Objectives: Evaluate the bioequivalence (BE) of two oral tablets formulations of diclofenac 150 mg in healthy male subjects under fasting condition. This was a phase I, randomized, open label, balanced, two period, tw...Objectives: Evaluate the bioequivalence (BE) of two oral tablets formulations of diclofenac 150 mg in healthy male subjects under fasting condition. This was a phase I, randomized, open label, balanced, two period, two sequences, single oral dose, crossover, analyst blind study. Methods: Twenty four (24) healthy subjects were randomly assigned to one of two sequences protocol: 150 mg XR of reference formulation (R), diclofenac sodium in the first period or the test formulation (T), diclofenac potassium in the second or vice versa. The plasma concentrations were determined using a validated LC-MS/MS method. Pharmacokinetic (PK) parameters included: maximum plasma concentration (C<sub>max</sub>), area under the plasma concentration—time curve from time 0 to the last measurable concentration (AUC<sub>0-t</sub>), and area under the plasma concentration—time from time 0 to infinity (AUC<sub>0-∞</sub>), were evaluated for BE. Results: The results showed that 90% confidence intervals for the test/reference geometric mean ratios (GMR) of C<sub>max</sub> (90.43 - 107.17), AUC<sub>0-t</sub> (93.08 - 116.46) and AUC<sub>0-∞</sub> (92.52 - 117.39) were within the BE (80% - 125%) acceptance range. Conclusions: Two formulations, reference product (R) Voltaren® (diclofenac sodium) of Novartis and test product (T), Diklason Bi (diclofenac potassium) of Laboratorios Leti S.A.V., with a single dose of 150 mg XR, under fasting conditions were bioequivalent. No severe, serious or unexpected adverse events (AEs) were reported in this study.展开更多
Obesity can be considered as a chronic illness of epidemic proportion and its incidents have increased exponentially in recent years. The use of anti-obesity drugs such as sibutramine is somewhat helpful. There is a n...Obesity can be considered as a chronic illness of epidemic proportion and its incidents have increased exponentially in recent years. The use of anti-obesity drugs such as sibutramine is somewhat helpful. There is a need to quantify such drugs in biological samples, which is generally quite difficult. In this report, we developed and validated a simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of sibutramine (SB) and its two metabolites N-des methyl sibutramine (DSB) and N-di desmethyl sibutramine (DDSB) in human plasma. Zorbax SBC18 (4.6 mm 75 mm, 3.5 mm, 80 A) analytical column and 5 mM ammonium formate:acetonitrile (10:90, v/v) mobile phase were used for chromatographic separation of SB, DSB and DDSB. Multiple reaction monitoring (MRM) in the positive mode was used to detect SB, DSB and DDSB at m/z 280.3/124.9, 266.3/ 125.3 and 252.2/124.9, respectively. Liquid-liquid extraction was used for the extraction of analytes and internal standard from human plasma. This method was validated over a linear concentration range of 10.0-10,000.0 pg/mL for SB, DSB and DDSB with correlation coefficients (r) of Z0.9997. The drug and the two metabolites were stable in plasma samples. The validated method was successfully applied in a bioequivalence and pharmacokinetic study with human volunteers under fasting condition.展开更多
The aim of the present study was to investigate virtual population pharmacokinetic using physiologically based pharmacokinetic(PBPK) model for evaluating bioequivalence of oral lacidipine formulations in dogs. The dis...The aim of the present study was to investigate virtual population pharmacokinetic using physiologically based pharmacokinetic(PBPK) model for evaluating bioequivalence of oral lacidipine formulations in dogs. The dissolution behaviors of three lacidipine formulations including one commercial product and two self-made amorphous solid dispersions(ASDs)capsules were determined in 0.07% Tween 80 media. A randomized 3-period crossover design in 6 healthy beagle dogs after oral administration of the three formulations at a single dose of 4 mg was conducted. The PBPK modeling was utilized for the virtual bioequivalence study.In vitro dissolution experiment showed that the dissolution behaviors of lacidipine amorphous solid dispersions(ASDs) capsules, which was respectively prepared by HPMC-E5 or Soluplus, as polymer displayed similar curves compared with the reference formulation in 0.07% Tween 80 media. In vivo pharmacokinetics experiments showed that three formulations had comparable maximum plasma drug concentration(Cmax), and the time(Tmax) to reach Cmax of lacidipine tablet, which was prepared by Soluplus, as polymer was slower than other two formulations in consistency with the in vitro dissolution rate. The 90% confidence interval(CI) for the Cmax, AUC0–24 h and AUC0–∞ of the ratio of the test drug to the reference drug exceeded the acceptable bioequivalence(BE) limits(0.80–1.25). However, the 90% CI of the AUC0–24 h, AUC0–∞ and Cmax of the ratio of test to reference drug were within the BE limit,calculated using PBPK modeling when the virtual subjects reached 24 dogs. The results all demonstrated that virtual bioequivalence study can overcome the inequivalence caused by inter-subject variability of the 6 beagle dogs involved in in vivo experiments.展开更多
Bioequivalence(BE) assessment of topical dermatological products is a long standing challenge. The development of generic topical dermatological products has often been hampered due to the limited number of acceptable...Bioequivalence(BE) assessment of topical dermatological products is a long standing challenge. The development of generic topical dermatological products has often been hampered due to the limited number of acceptable approaches, which are capable of determining the BE between generic products and reference list products. The aim of this manuscript is to review different BE assessment approaches of topical dermatological products. Besides, the advances in BE evaluation and biowaivers are also provided. Currently, except in the case of dermatological corticosteroids, the golden rule to establish the BE of most topical dermatological products still heavily relied on clinical endpoint trials,which are often unreliable, time-consuming and expensive. The regulatory agencies and pharmaceutical industries are forging ahead to the development of new surrogate BE assessment approaches for other topical dermatological products. These promising approaches include dermatopharmacokinetic study(DPK), dermal microdialysis(DMD), in vitro studies, pharmacokinetic study(PK), near-infrared spectrometry(NIR), and confocal Raman spectroscopy(CRS). In addition, the expansion of biowaivers for topical dermatological products has been explored by pharmaceutical scientists. In conclusion, to accelerate the development and approval of topical dermatological products, emphasis should be put on the following areas, i.e., optimizing and standardizing the existing BE assessment methods, exploring novel alternatives of BE assessment approaches, and expanding biowaivers for topical dermatological products.展开更多
A sensitive and selective method has been proposed for the simultaneous determination of amlodipine(AML),valsartan(VAL) and hydrochlorothiazide(HCTZ) in human plasma by liquid chromatography–tandem mass spectrometry...A sensitive and selective method has been proposed for the simultaneous determination of amlodipine(AML),valsartan(VAL) and hydrochlorothiazide(HCTZ) in human plasma by liquid chromatography–tandem mass spectrometry(LC–MS/MS). The analytes and their deuterated analogs were quantitatively extracted from100 μL human plasma by solid phase extraction on Oasis HLB cartridges. The chromatographic separation of the analytes was achieved on a Chromolith RP18 e(100 mm × 4.6 mm) analytical column within 2.5 min. The resolution factor between AML and VAL, AML and HCTZ, and VAL and HCTZ was 2.9, 1.5 and 1.4, respectively,under isocratic conditions. The method was validated over a dynamic concentration range of 0.02–20.0 ng/m L for AML, 5.00–10,000 ng/m L for VAL and 0.20–200 ng/m L for HCTZ. Ion-suppression/enhancement effects were investigated by post-column infusion technique. The mean IS-normalized matrix factors for AML, VAL and HCTZ were 0.992, 0.994 and 0.998, respectively. The intra-batch and inter-batch precision(% CV) across quality control levels was ≤ 5.56% and the recovery was in the range of 93.4%–99.6% for all the analytes. The method was successfully applied to a bioequivalence study of 5 mg AML + 160 mg VAL + 12.5 mg HCTZ tablet formulation(test and reference) in 18 healthy Indian males under fasting. The mean log-transformed ratios of C max, AUC0–120 h and AUC0-inf and their 90% CIs were within 90.2%–102.1%. The assay reproducibility was demonstrated by reanalysis of 90 incurred samples.展开更多
Orally inhaled drug products(OIPs),such as corticosteroids and bronchodilators,are at the forefront of asthma and chronic obstructive pulmonary disease treatments,two diseases that afflict worldwide populations.Introd...Orally inhaled drug products(OIPs),such as corticosteroids and bronchodilators,are at the forefront of asthma and chronic obstructive pulmonary disease treatments,two diseases that afflict worldwide populations.Introducing generics of these products is essential,as the pricing of these medications remain a barrier to adequate patient care.Currently,there is no consensus between regulatory bodies as to the bioequivalence and equivalence requirements of OIPs that are intended for local action in the lungs.This manuscript critically reviews these requirements and presents future directions for clinicians,scientists,and regulators to consider to optimize the development and approval of OIPs.展开更多
BACKGROUND The pharmacokinetics and bioequivalence of esomeprazole in healthy Chinese subjects and the effects of food on the pharmacokinetics have not been well studied.AIM To evaluate the pharmacokinetic characteris...BACKGROUND The pharmacokinetics and bioequivalence of esomeprazole in healthy Chinese subjects and the effects of food on the pharmacokinetics have not been well studied.AIM To evaluate the pharmacokinetic characteristics of esomeprazole magnesium(Eso)enteric-coated capsule in the healthy subjects in China and the bioequivalence of the two formulations.METHODS This study was conducted in the Phase I Clinical Trial Unit of the Affiliated Hospital of Changchun University of Chinese Medicine.A total of 64 healthy subjects were enrolled in the study.Thirty-two subjects fasted or fed,took the test or reference formulation Eso enteric-coated capsule by a four-cycle,two-sequence crossover of fasting/fed,self-controlled method.The liquid chromatographymass spectrometry was performed to determine the drug plasma concentration at 16 different time points within 12 h after drug administration.The pharmacokinetic parameters Cmax,area under the curve(AUC)0-t,and AUC0-inf were calculated to evaluate the bioequivalence.RESULTS Pharmacokinetic parameters were evaluated after subjects took the test formulation and control formulation under fasting status.The ratio of geometric means of Cmax was 104.15%,with a confidence interval(CI)of 98.20-110.46%.The ratio of geometric means of AUC0-t was 105.26%,with a CI of 99.80-111.01%.The ratio of geometric means of AUC0-inf was 105.37%,with a CI of 99.97-111.06%.The pharmacokinetic parameters were also evaluated after subjects took the reference formulation of Eso enteric-coated capsule after eating.The upper limit of 95%CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state Cmax was-0.1689,and the point estimate was 0.9509(0.80-1.25).The upper limit of 95%CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state AUC0-t was-0.1015(≤0),and the point estimate was 0.9003(0.80-1.25).The upper limit of 95%CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state AUC0-inf was-0.0593(≤0),and the point estimate was 0.8453(0.80-1.25).The results indicated that the two formulations were bioequivalent under both fasting and fed states.CONCLUSION The two types of esomeprazole tablets were bioequivalent under both fasting and fed states,and both were generally well tolerated.展开更多
Objective To evaluate the bioavailability and bioequivalence of oseltamivir capsule in Chinese health male volunteers.Methods A randomized,two period,two treatment,two sequence crossover bioequivalence trial was desig...Objective To evaluate the bioavailability and bioequivalence of oseltamivir capsule in Chinese health male volunteers.Methods A randomized,two period,two treatment,two sequence crossover bioequivalence trial was designed,24 Chinese health volunteers were randomly divided into two groups,each group was orally given single dose oseltamivir phosphate(tamifla)or AMMS 607 capsule.The active metabolite oseltamivir carboxylate of oseltamivir in the plasma were determined by liquid chromatographic-tandem mass spectrometric(LC-MS/MS)method.The pharmacokinetics parameters and relative bioavailability were calculated to evaluate the bioequivalence of AMMS 607 and tamifla.Results Cmax of the AMMS 607 and tamifla were 602.07±153.27 ng·mL-1 and 620.09±132.39 ng·mL-1 respectively;tmax were 4.2±1.1 h and 4.8±1.0 h;t1/2β were 6.60±0.87 h and 6.61±0.83 h;MRT were 10.00±1.77 h and 10.40±1.62 h;AUC0-24 were 6285.88±1083.66 ng·h·mL-1 and 6546.01±1199.32 ng·h·mL-1;Compared with the reference of tamifla capsule,the bioavailability F0-tn of AMMS 607 capsule was 99.5±27.7%.The main pharmacokinetics parameters of AUC0-24,Cmax and Tmax showed no statistically significant difference between the two capsules.Conclusions The AMMS 607 capsule and tamifla capsule are bioequivalent.展开更多
A sensitive and selective liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of rosuvastatin in human plasma using gliclazide as ...A sensitive and selective liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of rosuvastatin in human plasma using gliclazide as an internal standard (IS). Rosuvastatin and gliclazide in plasma were extracted with ethyl acetate, separated on a C18 reversed phase column, eluted with mobile phase of acetonitrile-methanoic acid (0.1%) (60:40, v/v), ionized by positive ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor → product ions of m/z 482.1 → 258.1 for rosuvastatin and m/z 324.2 → 127.2 for IS, respectively. The calibration curve was linear (r2 > 0.99, n = 5) over the concentration range of 0.1 - 60 ng/mL. The speci?city, matrix effect, recovery, sensitivity, linearity, accuracy, precision, and stabilities were validated for rosuvastatin in human plasma. In conclusion, the validation results showed that this method was sensitive, economical and less toxic and it can successfully ful?ll the requirement of bioequivalence study of rosuvastatin calcium tablets in Chinese healthy volunteers.展开更多
Objective To develop methods for determining a suitable sample size for bioequivalence assessment of generic topical ophthalmic drugs using crossover design with serial sampling schemes.Methods The power functions of ...Objective To develop methods for determining a suitable sample size for bioequivalence assessment of generic topical ophthalmic drugs using crossover design with serial sampling schemes.Methods The power functions of the Fieller-type confidence interval and the asymptotic confidence interval in crossover designs with serial-sampling data are here derived.Simulation studies were conducted to evaluate the derived power functions.Results Simulation studies show that two power functions can provide precise power estimates when normality assumptions are satisfied and yield conservative estimates of power in cases when data are log-normally distributed.The intra-correlation showed a positive correlation with the power of the bioequivalence test.When the expected ratio of the AUCs was less than or equal to 1, the power of the Fieller-type confidence interval was larger than the asymptotic confidence interval.If the expected ratio of the AUCs was larger than 1, the asymptotic confidence interval had greater power.Sample size can be calculated through numerical iteration with the derived power functions.Conclusion The Fieller-type power function and the asymptotic power function can be used to determine sample sizes of crossover trials for bioequivalence assessment of topical ophthalmic drugs.展开更多
A selective, sensitive and rugged liquid chromatography–tandem mass spectrometry(LC–MS/MS) assay has been developed for the simultaneous determination of doxepin(Dox) and its pharmacologically active metabolite, nor...A selective, sensitive and rugged liquid chromatography–tandem mass spectrometry(LC–MS/MS) assay has been developed for the simultaneous determination of doxepin(Dox) and its pharmacologically active metabolite, nordoxepin(NDox) in human plasma. The analytes and their internal standards(IS)were extracted from 500 m L of human plasma by liquid-liquid extraction using methyl tert-butyl ether.Chromatographic separation was achieved on Hypurity C8 column(100 mm ? 4.6 mm, 5 mm) using a mixture of acetonitrile-methanol(95:5, v/v) and 2.0 mM ammonium formate in 93:7(v/v) ratio. Detection was accomplished by tandem mass spectrometry in the positive ionization and multiple reaction monitoring acquisition mode. The protonated precursor to product ion transitions studied for Dox, NDox,and their corresponding ISs, propranolol and desipramine, were m/z 280.1-107.0, 266.0-107.0,260.1-116.1 and 267.1-72.1, respectively. A linear dynamic range of 15.0–3900 pg/mL for Dox and 5.00–1300 pg/mL for NDox was established with mean correlation coefficient(r2) of 0.9991 and 0.9993, respectively. The extraction recovery ranged from 86.6%–90.4% and 88.0%–99.1% for Dox and NDox, respectively. The intra-batch and inter-batch precision(% CV) across quality control levels was r 8.3% for both the analytes. Stability evaluated under different storage conditions showed no evidence of degradation and the % change in stability samples compared to nominal concentration ranged from 4.7% to12.3%. The method was successfully applied to a bioequivalence study of 6 mg doxepin hydrochloride orally disintegrating tablet in 41 healthy Indian subjects under fasting and fed conditions.展开更多
A highly sensitive and selective high performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of alverine(ALV) and its active metabolite, para hydroxy alve...A highly sensitive and selective high performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of alverine(ALV) and its active metabolite, para hydroxy alverine(PHA), in human plasma. For sample preparation, solid phase extraction of analytes was performed on Phenomenex Strata-X cartridges using alverine-d5 as the internal standard. The analytes were separated on Symmetry Shield RP18(150 mm×3.9 mm, 5 μm) column with a mobile phase consisting of acetonitrile and10 mM ammonium formate(65:35, v/v). Detection and quantitation was done by electrospray ionization mass spectrometry in the positive mode using multiple reaction monitoring. The assay method was fully validated over the concentration range of 15.0–15,000 pg/mL for ALV and 30.0–15,000 pg/mL for PHA. The intra-day and inter-day accuracy and precision(% CV) ranged from 94.00% to 96.00% and 0.48% to 4.15% for both the analytes. The mean recovery obtained for ALV and PHA was 80.59% and 81.26%, respectively. Matrix effect,expressed as IS-normalized matrix factor ranged from 0.982 to 1.009 for both the analytes. The application of the method was demonstrated for the specific analysis of ALV and PHA for a bioequivalence study in 52 healthy subjects using 120 mg ALV capsules. The assay reproducibility was also verified by reanalysis of 175 incurred subject samples.展开更多
Abacavir/lamivudine is a combination of two synthetic nucleoside analogues which is indicated in antiretroviral combination therapy for the treatment of human immunodeficiency virus(HIV)infection in adults and adolesc...Abacavir/lamivudine is a combination of two synthetic nucleoside analogues which is indicated in antiretroviral combination therapy for the treatment of human immunodeficiency virus(HIV)infection in adults and adolescents[1].A generic product of abacavir/lamivudine has been developed with lower price by the Government Pharmaceutical Organization(GPO)to be an alternative choice of related physicians and patients who will gain access to the lower price medicines at the same quality and safety as the reference product.展开更多
AIM:To assess the relative bioavailability and pharmacokinetic properties of two formulations(test and reference) of Lafutidine 10 mg.METHODS:The study was performed as an open label,randomized,two-way,two-period,two-...AIM:To assess the relative bioavailability and pharmacokinetic properties of two formulations(test and reference) of Lafutidine 10 mg.METHODS:The study was performed as an open label,randomized,two-way,two-period,two-treatment,single dose cross-over bioequivalence study,under non-fed condition to compare the pharmacokinetic prof iles of the lafutidine formulation manufactured by Emcure Pharmaceuticals Ltd.,India using an indigenously developed active pharmaceutical ingredient(API) and the commercially available Stogra formulation,of UCB Japan Co.,Ltd.,Japan.The two treatments were separated by a washout period of 5 d.After an overnight fasting period of 10 h,the subjects were administered either the test or the reference medication as per the randomization schedule.Blood samples were collected at intervals up to 24 h,as per the approved protocol.Concentrations of lafutidine in plasma were analyzed by a validated liquid chromatography/tandem mass spectrometry(LC/MS/MS) method,and a non-compartmental model was used for pharmacokinetic analysis.The pharmacokinetic parameters were subjected to a 4-way ANOVA accounting for sequence,subjects,period and treatment.Statistical significance was evaluated at 95% conf idence level(P ≥ 0.05).RESULTS:The mean(±SD) values of the pharmacokinetic parameters(test vs reference) were Cmax(265.15±49.84 ng/mL vs 246.79±29.30 ng/mL,P<0.05),Area under the curve(AUC)(0-t)(1033.13±298.74 ng.h/mL vs 952.93±244.07 ng.h/mL,P < 0.05),AUC(0-∞)(1047.61±301.22 ng.h/mL vs 964.21±246.45 ng.h/mL,P<0.05),and tv2(1.92±0.94 h vs 2.05±1.01 h,P<0.05).The 90% conf idence intervals(CI) for the test/reference ratio of mean Cmax,AUC(0-t),and AUC(0-∞) were within the acceptable range of 80.00 to 125.00.The mean times(± SD) to attain maximal plasma concentration(tmax) of lafutidine were 0.95±0.24 h vs 1.01±0.29 h(P<0.05) for the test and the reference formulations respectively.Both the formulations were well tolerated.展开更多
The goal of our research was to compare the pharmacokinetics and evaluate the bioequivalence of two brands of cephradine 500 mg capsules in 24 normal Korean volunteers. The plasma samples were acquired at 13 time poin...The goal of our research was to compare the pharmacokinetics and evaluate the bioequivalence of two brands of cephradine 500 mg capsules in 24 normal Korean volunteers. The plasma samples were acquired at 13 time points for 8 h after administration. The concentrations of cephradine in human plasma were measured by a high-performance liquid chromatography (HPLC). Isocratic mobile phase which consisted of acetonitrile, methanol, and 20 mM potassium phosphate (15/5/80, v/v/v, pH 3.48) was used to separate the analytical column cosmosil cholester (250 × 4.6 mm, 3 μm). Analytes were detected in ultraviolet (260 nm). The novel analytical method was described as simple sample preparation, a short retention time (less than 6 min) and making it suitable for use in clinical trials. Pharmacokinetic parameters, such as AUC0-t (20.54 vs 18.42 μg·h/mL), AUC0-infinity (21.22 vs 19.14 μg·h/mL), Cmax (12.69 vs 12.81 μg/mL), Tmax (1.22 vs 0.92 h), half-life (1.02 vs 1.13 h), extrapolation (3.22% vs 3.75%), and Ke (0.73 vs 0.69 h–1) were determined for the reference and test drugs in plasma. Pharmacokinetic parameters with a 90% confidence interval were 87% - 95% for AUC0-t and 91% - 115% for Cmax. They were satisfied within the bioequivalence range 80% - 125% of the KFDA guidelines. Therefore, our HPLC method was well applied in a bioequivalence and pharmacokinetic study of two formulations in normal subjects.展开更多
A sensitive and reproducible liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of amlodipine in human plasma, with gliclazide a...A sensitive and reproducible liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of amlodipine in human plasma, with gliclazide as an internal standard (IS). The analyte was extracted with ethyl acetate and analyzed on a Diamond C18 (150 mm× 4.6 mm, 5 μm) column. The mobile phase was composed of methanol ?10 mM ammonium acetate with gradient flow rates and gradient conditions. Amlodipine and IS were ionized by positive ion pneumatically assisted electrospray and detected in the multi-reaction monitoring (MRM) mode using precursor→productions of m/z 409.2→238.1, 294.1 and m/z 324.2→127.3, respectively. The specificity, matrix effect, recovery, sensitivity, linearity, accuracy, precision, and stabilities were all validated over the concentration range of 0.05 - 12 ng/mL. The 90% confidence interval (CI) for AUC0-t, AUC0-∞ and Cmax ratios (test: reference) were all within 80% - 125% interval proposed by FDA. It is concluded that the validated method can successfully fulfill the requirement of clinical bioequivalence study of amlodipine in healthy Chinese subjects after administration of amlodipine/losartan combination tablets and amlodipine tablets, and the test and reference tablets were bioequivalent.展开更多
Aims: The present study was designed to assess the comparative bio-equivalence of Doxysol® and Doxymed® in healthy broiler chickens after oral administration of both products in a dose of 20 mg doxycycli...Aims: The present study was designed to assess the comparative bio-equivalence of Doxysol® and Doxymed® in healthy broiler chickens after oral administration of both products in a dose of 20 mg doxycycline/kg.b.wt. Materials and Methods: Twenty broiler chickens were divided into two groups. The first group was designed to study the pharmacokinetics of Doxysol, while the 2nd group was designed to study the pharmacokinetics of Doxymed. Each broiler chickens in both groups were injected intravenously with 20 mg doxycycline/kg.b.wt. Blood samples were obtained from the wing vein and collected immediately before and at 5, 15, 30 minute, 1, 2, 4, 6, 8, 12 and 24 hours after a single intravenous or oral administration. Results: Doxycycline in both products obeyed a two compartments open model following I.V. injection in a dose of 20 mg/kg.b.wt. The disposition kinetics of Doxysol® and Doxymed® following oral administration of 20 mg doxycycline base/kg.b.wt. revealed that the maximum blood concentration [Cmax.] were 4.70 and 4.65 μg/ml and attained at [tmax.] of 1.30 and 1.40 hours, respectively. Doxycycline in Doxysol® and Doxymed® was eliminated with half-lives [t0.5(β)] equal to 1.98 and 2.31 hours, respectively. The mean systemic bioavailability of doxycycline in Doxysol® and Doxymed® after oral administration in healthy chickens was 92.57 and 88.21%, respectively. Conclusion: Doxymed® is bioequivalent to Doxysol® since Cmax test/Cmax reference and AUCtest/AUCreference ratios were 99% and 90%, respectively.展开更多
Background: Telmisartan is a highly variable drug which is used to treat hypertension. This study compared to compare the bioavailability of two 40 mg Telmisartan tablets in adult and healthy Bangladeshi subjects. Mat...Background: Telmisartan is a highly variable drug which is used to treat hypertension. This study compared to compare the bioavailability of two 40 mg Telmisartan tablets in adult and healthy Bangladeshi subjects. Materials and Method: This study was open label, randomized, laboratory blind, single dose, three periods, two treatments, three-sequence, partial-replicate, crossover and comparative oral bioavailability study. In this study, 18 Bangladeshi subjects were enrolled and 17 subjects were completed. Serial blood samples were collected up to 96 hours following drug administration. By using Liquid Chromatography Mass Spectrometry (LC-MS/MS) method, plasma concentrations of Telmisartan were determined. Results: The two formulations of Telmisartan were considered bioequivalent if 90% Confidence Interval (CI) fall within the range of 80.00% - 125.00% for AUC parameters and reference-scaled-average bioequivalence of 69.84% - 143.19% for C<sub>max</sub>. The 90% Confidence Interval for C<sub>max</sub>, AUC<sub>0-t</sub> & AUC<sub>0-∞</sub> was found 84.88% - 107.79%, 89.76% - 109.55%, and 91.20% - 114.52%, respectively. Conclusion: According to rate and extent of absorption with the single dose of Reference Product (R): Micardis<sup><sup><sup>®</sup></sup></sup> 40 mg Tablet, under fasting conditions, a single dose of Telmisartan 40 mg Tablet is bioequivalent.展开更多
A method for the determination of carvedilol in human plasma was developed using a high-performance liquid chromatography with tandem mass spectrometer (HPLC-MS/MS). Plasma samples were deproteinized using acetonitril...A method for the determination of carvedilol in human plasma was developed using a high-performance liquid chromatography with tandem mass spectrometer (HPLC-MS/MS). Plasma samples were deproteinized using acetonitrile and the supernatant was directly injected onto the HPLC column without any preparative steps. Chromatography was performed on a reversed-phase (C18) column with isocratic mobile phase for 2 min. The calibration curve was linear over the range of 2 to100 ng/ml (R2 > 0.9998) and the lower limit of quantitation (LLOQ) was 2 ng/ml. This method showed acceptable precision and accuracy, good recovery from the plasma matrix, and stability during the analytical procedures. When its application to the bioequivalence test of two carvedilol 25 mg tablet formulations in male healthy 28 volunteers, this validated analysis method was appropriate resulting in the bioequivalence of two formulations: no statistically significant difference was observed between the logarithmic transformed area under curve (AUC) and maximum plasma concentration (Cmax) values of the two formulations. The 90% confidence interval for the ratio of the above mentioned two parameters were within the bioequivalence limit of 0.80-1.25. These results suggested that the HPLC-MS/MS analysis method developed was suitable for the carvedilol analysis in human plasma.展开更多
The aim of this study was to apply the reference-scaled average bioequivalence(RSABE)approach to evaluate the bioequivalence of 2 formulations of agomelatine,and to investigate the pharmacokinetic properties of agomel...The aim of this study was to apply the reference-scaled average bioequivalence(RSABE)approach to evaluate the bioequivalence of 2 formulations of agomelatine,and to investigate the pharmacokinetic properties of agomelatine in Chinese healthy male subjects.This was performed in a single-dose,randomized-sequence,open-label,four-way crossover study with a one-day washout period between doses.Healthy Chinese males were randomly assigned to receive 25 mg of either the test or reference formulation.The formulations were considered bioequivalent if 90% confidence intervals(CIs)for the log-transformed ratios and ratio of geometric means(GMR)of AUC and C_(max) of agomelatine were within the predetermined bioequivalence range based on RSABE method.Results showed that both of the90% CIs for the log-transformed ratios of AUC and C_(max) of 7-desmethyl-agomelatine and 3-hydroxyagomelatine were within the predetermined bioequivalence range.The 90% CIs for natural logtransformed ratios of C_(max) ,AUC_(0–t)and AUC_(0–∞) of agomelatine(104.42–139.86,101.33–123.83 and97.90–117.94)were within the RSABE acceptance limits,and 3-hydroxy-agomelatine(105.55–123.03,101.95–109.10 and 101.72–108.70)and 7-desmethyl-agomelatine(104.50–125.23,102.36–111.50 and101.62–110.64)were within the FDA bioequivalence definition intervals(0.80–1.25 for AUC and0.75–1.33 for C_(max)).The RSABE approach was successful in evaluating the bioequivalence of these two formulations.展开更多
文摘Objectives: Evaluate the bioequivalence (BE) of two oral tablets formulations of diclofenac 150 mg in healthy male subjects under fasting condition. This was a phase I, randomized, open label, balanced, two period, two sequences, single oral dose, crossover, analyst blind study. Methods: Twenty four (24) healthy subjects were randomly assigned to one of two sequences protocol: 150 mg XR of reference formulation (R), diclofenac sodium in the first period or the test formulation (T), diclofenac potassium in the second or vice versa. The plasma concentrations were determined using a validated LC-MS/MS method. Pharmacokinetic (PK) parameters included: maximum plasma concentration (C<sub>max</sub>), area under the plasma concentration—time curve from time 0 to the last measurable concentration (AUC<sub>0-t</sub>), and area under the plasma concentration—time from time 0 to infinity (AUC<sub>0-∞</sub>), were evaluated for BE. Results: The results showed that 90% confidence intervals for the test/reference geometric mean ratios (GMR) of C<sub>max</sub> (90.43 - 107.17), AUC<sub>0-t</sub> (93.08 - 116.46) and AUC<sub>0-∞</sub> (92.52 - 117.39) were within the BE (80% - 125%) acceptance range. Conclusions: Two formulations, reference product (R) Voltaren® (diclofenac sodium) of Novartis and test product (T), Diklason Bi (diclofenac potassium) of Laboratorios Leti S.A.V., with a single dose of 150 mg XR, under fasting conditions were bioequivalent. No severe, serious or unexpected adverse events (AEs) were reported in this study.
文摘Obesity can be considered as a chronic illness of epidemic proportion and its incidents have increased exponentially in recent years. The use of anti-obesity drugs such as sibutramine is somewhat helpful. There is a need to quantify such drugs in biological samples, which is generally quite difficult. In this report, we developed and validated a simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of sibutramine (SB) and its two metabolites N-des methyl sibutramine (DSB) and N-di desmethyl sibutramine (DDSB) in human plasma. Zorbax SBC18 (4.6 mm 75 mm, 3.5 mm, 80 A) analytical column and 5 mM ammonium formate:acetonitrile (10:90, v/v) mobile phase were used for chromatographic separation of SB, DSB and DDSB. Multiple reaction monitoring (MRM) in the positive mode was used to detect SB, DSB and DDSB at m/z 280.3/124.9, 266.3/ 125.3 and 252.2/124.9, respectively. Liquid-liquid extraction was used for the extraction of analytes and internal standard from human plasma. This method was validated over a linear concentration range of 10.0-10,000.0 pg/mL for SB, DSB and DDSB with correlation coefficients (r) of Z0.9997. The drug and the two metabolites were stable in plasma samples. The validated method was successfully applied in a bioequivalence and pharmacokinetic study with human volunteers under fasting condition.
基金the National Natural Science Foundation of China (No. 81173009)the Technology Bureau in Shenyang (No. ZCJJ2013402)the Project for New Century Excellent Talents of Ministry of Education (No. NCET-12-1015)
文摘The aim of the present study was to investigate virtual population pharmacokinetic using physiologically based pharmacokinetic(PBPK) model for evaluating bioequivalence of oral lacidipine formulations in dogs. The dissolution behaviors of three lacidipine formulations including one commercial product and two self-made amorphous solid dispersions(ASDs)capsules were determined in 0.07% Tween 80 media. A randomized 3-period crossover design in 6 healthy beagle dogs after oral administration of the three formulations at a single dose of 4 mg was conducted. The PBPK modeling was utilized for the virtual bioequivalence study.In vitro dissolution experiment showed that the dissolution behaviors of lacidipine amorphous solid dispersions(ASDs) capsules, which was respectively prepared by HPMC-E5 or Soluplus, as polymer displayed similar curves compared with the reference formulation in 0.07% Tween 80 media. In vivo pharmacokinetics experiments showed that three formulations had comparable maximum plasma drug concentration(Cmax), and the time(Tmax) to reach Cmax of lacidipine tablet, which was prepared by Soluplus, as polymer was slower than other two formulations in consistency with the in vitro dissolution rate. The 90% confidence interval(CI) for the Cmax, AUC0–24 h and AUC0–∞ of the ratio of the test drug to the reference drug exceeded the acceptable bioequivalence(BE) limits(0.80–1.25). However, the 90% CI of the AUC0–24 h, AUC0–∞ and Cmax of the ratio of test to reference drug were within the BE limit,calculated using PBPK modeling when the virtual subjects reached 24 dogs. The results all demonstrated that virtual bioequivalence study can overcome the inequivalence caused by inter-subject variability of the 6 beagle dogs involved in in vivo experiments.
文摘Bioequivalence(BE) assessment of topical dermatological products is a long standing challenge. The development of generic topical dermatological products has often been hampered due to the limited number of acceptable approaches, which are capable of determining the BE between generic products and reference list products. The aim of this manuscript is to review different BE assessment approaches of topical dermatological products. Besides, the advances in BE evaluation and biowaivers are also provided. Currently, except in the case of dermatological corticosteroids, the golden rule to establish the BE of most topical dermatological products still heavily relied on clinical endpoint trials,which are often unreliable, time-consuming and expensive. The regulatory agencies and pharmaceutical industries are forging ahead to the development of new surrogate BE assessment approaches for other topical dermatological products. These promising approaches include dermatopharmacokinetic study(DPK), dermal microdialysis(DMD), in vitro studies, pharmacokinetic study(PK), near-infrared spectrometry(NIR), and confocal Raman spectroscopy(CRS). In addition, the expansion of biowaivers for topical dermatological products has been explored by pharmaceutical scientists. In conclusion, to accelerate the development and approval of topical dermatological products, emphasis should be put on the following areas, i.e., optimizing and standardizing the existing BE assessment methods, exploring novel alternatives of BE assessment approaches, and expanding biowaivers for topical dermatological products.
文摘A sensitive and selective method has been proposed for the simultaneous determination of amlodipine(AML),valsartan(VAL) and hydrochlorothiazide(HCTZ) in human plasma by liquid chromatography–tandem mass spectrometry(LC–MS/MS). The analytes and their deuterated analogs were quantitatively extracted from100 μL human plasma by solid phase extraction on Oasis HLB cartridges. The chromatographic separation of the analytes was achieved on a Chromolith RP18 e(100 mm × 4.6 mm) analytical column within 2.5 min. The resolution factor between AML and VAL, AML and HCTZ, and VAL and HCTZ was 2.9, 1.5 and 1.4, respectively,under isocratic conditions. The method was validated over a dynamic concentration range of 0.02–20.0 ng/m L for AML, 5.00–10,000 ng/m L for VAL and 0.20–200 ng/m L for HCTZ. Ion-suppression/enhancement effects were investigated by post-column infusion technique. The mean IS-normalized matrix factors for AML, VAL and HCTZ were 0.992, 0.994 and 0.998, respectively. The intra-batch and inter-batch precision(% CV) across quality control levels was ≤ 5.56% and the recovery was in the range of 93.4%–99.6% for all the analytes. The method was successfully applied to a bioequivalence study of 5 mg AML + 160 mg VAL + 12.5 mg HCTZ tablet formulation(test and reference) in 18 healthy Indian males under fasting. The mean log-transformed ratios of C max, AUC0–120 h and AUC0-inf and their 90% CIs were within 90.2%–102.1%. The assay reproducibility was demonstrated by reanalysis of 90 incurred samples.
文摘Orally inhaled drug products(OIPs),such as corticosteroids and bronchodilators,are at the forefront of asthma and chronic obstructive pulmonary disease treatments,two diseases that afflict worldwide populations.Introducing generics of these products is essential,as the pricing of these medications remain a barrier to adequate patient care.Currently,there is no consensus between regulatory bodies as to the bioequivalence and equivalence requirements of OIPs that are intended for local action in the lungs.This manuscript critically reviews these requirements and presents future directions for clinicians,scientists,and regulators to consider to optimize the development and approval of OIPs.
文摘BACKGROUND The pharmacokinetics and bioequivalence of esomeprazole in healthy Chinese subjects and the effects of food on the pharmacokinetics have not been well studied.AIM To evaluate the pharmacokinetic characteristics of esomeprazole magnesium(Eso)enteric-coated capsule in the healthy subjects in China and the bioequivalence of the two formulations.METHODS This study was conducted in the Phase I Clinical Trial Unit of the Affiliated Hospital of Changchun University of Chinese Medicine.A total of 64 healthy subjects were enrolled in the study.Thirty-two subjects fasted or fed,took the test or reference formulation Eso enteric-coated capsule by a four-cycle,two-sequence crossover of fasting/fed,self-controlled method.The liquid chromatographymass spectrometry was performed to determine the drug plasma concentration at 16 different time points within 12 h after drug administration.The pharmacokinetic parameters Cmax,area under the curve(AUC)0-t,and AUC0-inf were calculated to evaluate the bioequivalence.RESULTS Pharmacokinetic parameters were evaluated after subjects took the test formulation and control formulation under fasting status.The ratio of geometric means of Cmax was 104.15%,with a confidence interval(CI)of 98.20-110.46%.The ratio of geometric means of AUC0-t was 105.26%,with a CI of 99.80-111.01%.The ratio of geometric means of AUC0-inf was 105.37%,with a CI of 99.97-111.06%.The pharmacokinetic parameters were also evaluated after subjects took the reference formulation of Eso enteric-coated capsule after eating.The upper limit of 95%CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state Cmax was-0.1689,and the point estimate was 0.9509(0.80-1.25).The upper limit of 95%CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state AUC0-t was-0.1015(≤0),and the point estimate was 0.9003(0.80-1.25).The upper limit of 95%CI of the geometric mean ratio of pharmacokinetic parameters of Eso enteric-coated capsules in the postprandial state AUC0-inf was-0.0593(≤0),and the point estimate was 0.8453(0.80-1.25).The results indicated that the two formulations were bioequivalent under both fasting and fed states.CONCLUSION The two types of esomeprazole tablets were bioequivalent under both fasting and fed states,and both were generally well tolerated.
文摘Objective To evaluate the bioavailability and bioequivalence of oseltamivir capsule in Chinese health male volunteers.Methods A randomized,two period,two treatment,two sequence crossover bioequivalence trial was designed,24 Chinese health volunteers were randomly divided into two groups,each group was orally given single dose oseltamivir phosphate(tamifla)or AMMS 607 capsule.The active metabolite oseltamivir carboxylate of oseltamivir in the plasma were determined by liquid chromatographic-tandem mass spectrometric(LC-MS/MS)method.The pharmacokinetics parameters and relative bioavailability were calculated to evaluate the bioequivalence of AMMS 607 and tamifla.Results Cmax of the AMMS 607 and tamifla were 602.07±153.27 ng·mL-1 and 620.09±132.39 ng·mL-1 respectively;tmax were 4.2±1.1 h and 4.8±1.0 h;t1/2β were 6.60±0.87 h and 6.61±0.83 h;MRT were 10.00±1.77 h and 10.40±1.62 h;AUC0-24 were 6285.88±1083.66 ng·h·mL-1 and 6546.01±1199.32 ng·h·mL-1;Compared with the reference of tamifla capsule,the bioavailability F0-tn of AMMS 607 capsule was 99.5±27.7%.The main pharmacokinetics parameters of AUC0-24,Cmax and Tmax showed no statistically significant difference between the two capsules.Conclusions The AMMS 607 capsule and tamifla capsule are bioequivalent.
文摘A sensitive and selective liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of rosuvastatin in human plasma using gliclazide as an internal standard (IS). Rosuvastatin and gliclazide in plasma were extracted with ethyl acetate, separated on a C18 reversed phase column, eluted with mobile phase of acetonitrile-methanoic acid (0.1%) (60:40, v/v), ionized by positive ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor → product ions of m/z 482.1 → 258.1 for rosuvastatin and m/z 324.2 → 127.2 for IS, respectively. The calibration curve was linear (r2 > 0.99, n = 5) over the concentration range of 0.1 - 60 ng/mL. The speci?city, matrix effect, recovery, sensitivity, linearity, accuracy, precision, and stabilities were validated for rosuvastatin in human plasma. In conclusion, the validation results showed that this method was sensitive, economical and less toxic and it can successfully ful?ll the requirement of bioequivalence study of rosuvastatin calcium tablets in Chinese healthy volunteers.
基金supported by sub-project of National Major Scientific and Technological Special Project of China for ‘Significant New Drugs Development’[2015ZX09501008-004]
文摘Objective To develop methods for determining a suitable sample size for bioequivalence assessment of generic topical ophthalmic drugs using crossover design with serial sampling schemes.Methods The power functions of the Fieller-type confidence interval and the asymptotic confidence interval in crossover designs with serial-sampling data are here derived.Simulation studies were conducted to evaluate the derived power functions.Results Simulation studies show that two power functions can provide precise power estimates when normality assumptions are satisfied and yield conservative estimates of power in cases when data are log-normally distributed.The intra-correlation showed a positive correlation with the power of the bioequivalence test.When the expected ratio of the AUCs was less than or equal to 1, the power of the Fieller-type confidence interval was larger than the asymptotic confidence interval.If the expected ratio of the AUCs was larger than 1, the asymptotic confidence interval had greater power.Sample size can be calculated through numerical iteration with the derived power functions.Conclusion The Fieller-type power function and the asymptotic power function can be used to determine sample sizes of crossover trials for bioequivalence assessment of topical ophthalmic drugs.
文摘A selective, sensitive and rugged liquid chromatography–tandem mass spectrometry(LC–MS/MS) assay has been developed for the simultaneous determination of doxepin(Dox) and its pharmacologically active metabolite, nordoxepin(NDox) in human plasma. The analytes and their internal standards(IS)were extracted from 500 m L of human plasma by liquid-liquid extraction using methyl tert-butyl ether.Chromatographic separation was achieved on Hypurity C8 column(100 mm ? 4.6 mm, 5 mm) using a mixture of acetonitrile-methanol(95:5, v/v) and 2.0 mM ammonium formate in 93:7(v/v) ratio. Detection was accomplished by tandem mass spectrometry in the positive ionization and multiple reaction monitoring acquisition mode. The protonated precursor to product ion transitions studied for Dox, NDox,and their corresponding ISs, propranolol and desipramine, were m/z 280.1-107.0, 266.0-107.0,260.1-116.1 and 267.1-72.1, respectively. A linear dynamic range of 15.0–3900 pg/mL for Dox and 5.00–1300 pg/mL for NDox was established with mean correlation coefficient(r2) of 0.9991 and 0.9993, respectively. The extraction recovery ranged from 86.6%–90.4% and 88.0%–99.1% for Dox and NDox, respectively. The intra-batch and inter-batch precision(% CV) across quality control levels was r 8.3% for both the analytes. Stability evaluated under different storage conditions showed no evidence of degradation and the % change in stability samples compared to nominal concentration ranged from 4.7% to12.3%. The method was successfully applied to a bioequivalence study of 6 mg doxepin hydrochloride orally disintegrating tablet in 41 healthy Indian subjects under fasting and fed conditions.
基金the support and necessary facilities provided by Accutest Research Lab,Ahmedabad
文摘A highly sensitive and selective high performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of alverine(ALV) and its active metabolite, para hydroxy alverine(PHA), in human plasma. For sample preparation, solid phase extraction of analytes was performed on Phenomenex Strata-X cartridges using alverine-d5 as the internal standard. The analytes were separated on Symmetry Shield RP18(150 mm×3.9 mm, 5 μm) column with a mobile phase consisting of acetonitrile and10 mM ammonium formate(65:35, v/v). Detection and quantitation was done by electrospray ionization mass spectrometry in the positive mode using multiple reaction monitoring. The assay method was fully validated over the concentration range of 15.0–15,000 pg/mL for ALV and 30.0–15,000 pg/mL for PHA. The intra-day and inter-day accuracy and precision(% CV) ranged from 94.00% to 96.00% and 0.48% to 4.15% for both the analytes. The mean recovery obtained for ALV and PHA was 80.59% and 81.26%, respectively. Matrix effect,expressed as IS-normalized matrix factor ranged from 0.982 to 1.009 for both the analytes. The application of the method was demonstrated for the specific analysis of ALV and PHA for a bioequivalence study in 52 healthy subjects using 120 mg ALV capsules. The assay reproducibility was also verified by reanalysis of 175 incurred subject samples.
文摘Abacavir/lamivudine is a combination of two synthetic nucleoside analogues which is indicated in antiretroviral combination therapy for the treatment of human immunodeficiency virus(HIV)infection in adults and adolescents[1].A generic product of abacavir/lamivudine has been developed with lower price by the Government Pharmaceutical Organization(GPO)to be an alternative choice of related physicians and patients who will gain access to the lower price medicines at the same quality and safety as the reference product.
文摘AIM:To assess the relative bioavailability and pharmacokinetic properties of two formulations(test and reference) of Lafutidine 10 mg.METHODS:The study was performed as an open label,randomized,two-way,two-period,two-treatment,single dose cross-over bioequivalence study,under non-fed condition to compare the pharmacokinetic prof iles of the lafutidine formulation manufactured by Emcure Pharmaceuticals Ltd.,India using an indigenously developed active pharmaceutical ingredient(API) and the commercially available Stogra formulation,of UCB Japan Co.,Ltd.,Japan.The two treatments were separated by a washout period of 5 d.After an overnight fasting period of 10 h,the subjects were administered either the test or the reference medication as per the randomization schedule.Blood samples were collected at intervals up to 24 h,as per the approved protocol.Concentrations of lafutidine in plasma were analyzed by a validated liquid chromatography/tandem mass spectrometry(LC/MS/MS) method,and a non-compartmental model was used for pharmacokinetic analysis.The pharmacokinetic parameters were subjected to a 4-way ANOVA accounting for sequence,subjects,period and treatment.Statistical significance was evaluated at 95% conf idence level(P ≥ 0.05).RESULTS:The mean(±SD) values of the pharmacokinetic parameters(test vs reference) were Cmax(265.15±49.84 ng/mL vs 246.79±29.30 ng/mL,P<0.05),Area under the curve(AUC)(0-t)(1033.13±298.74 ng.h/mL vs 952.93±244.07 ng.h/mL,P < 0.05),AUC(0-∞)(1047.61±301.22 ng.h/mL vs 964.21±246.45 ng.h/mL,P<0.05),and tv2(1.92±0.94 h vs 2.05±1.01 h,P<0.05).The 90% conf idence intervals(CI) for the test/reference ratio of mean Cmax,AUC(0-t),and AUC(0-∞) were within the acceptable range of 80.00 to 125.00.The mean times(± SD) to attain maximal plasma concentration(tmax) of lafutidine were 0.95±0.24 h vs 1.01±0.29 h(P<0.05) for the test and the reference formulations respectively.Both the formulations were well tolerated.
文摘The goal of our research was to compare the pharmacokinetics and evaluate the bioequivalence of two brands of cephradine 500 mg capsules in 24 normal Korean volunteers. The plasma samples were acquired at 13 time points for 8 h after administration. The concentrations of cephradine in human plasma were measured by a high-performance liquid chromatography (HPLC). Isocratic mobile phase which consisted of acetonitrile, methanol, and 20 mM potassium phosphate (15/5/80, v/v/v, pH 3.48) was used to separate the analytical column cosmosil cholester (250 × 4.6 mm, 3 μm). Analytes were detected in ultraviolet (260 nm). The novel analytical method was described as simple sample preparation, a short retention time (less than 6 min) and making it suitable for use in clinical trials. Pharmacokinetic parameters, such as AUC0-t (20.54 vs 18.42 μg·h/mL), AUC0-infinity (21.22 vs 19.14 μg·h/mL), Cmax (12.69 vs 12.81 μg/mL), Tmax (1.22 vs 0.92 h), half-life (1.02 vs 1.13 h), extrapolation (3.22% vs 3.75%), and Ke (0.73 vs 0.69 h–1) were determined for the reference and test drugs in plasma. Pharmacokinetic parameters with a 90% confidence interval were 87% - 95% for AUC0-t and 91% - 115% for Cmax. They were satisfied within the bioequivalence range 80% - 125% of the KFDA guidelines. Therefore, our HPLC method was well applied in a bioequivalence and pharmacokinetic study of two formulations in normal subjects.
文摘A sensitive and reproducible liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of amlodipine in human plasma, with gliclazide as an internal standard (IS). The analyte was extracted with ethyl acetate and analyzed on a Diamond C18 (150 mm× 4.6 mm, 5 μm) column. The mobile phase was composed of methanol ?10 mM ammonium acetate with gradient flow rates and gradient conditions. Amlodipine and IS were ionized by positive ion pneumatically assisted electrospray and detected in the multi-reaction monitoring (MRM) mode using precursor→productions of m/z 409.2→238.1, 294.1 and m/z 324.2→127.3, respectively. The specificity, matrix effect, recovery, sensitivity, linearity, accuracy, precision, and stabilities were all validated over the concentration range of 0.05 - 12 ng/mL. The 90% confidence interval (CI) for AUC0-t, AUC0-∞ and Cmax ratios (test: reference) were all within 80% - 125% interval proposed by FDA. It is concluded that the validated method can successfully fulfill the requirement of clinical bioequivalence study of amlodipine in healthy Chinese subjects after administration of amlodipine/losartan combination tablets and amlodipine tablets, and the test and reference tablets were bioequivalent.
文摘Aims: The present study was designed to assess the comparative bio-equivalence of Doxysol® and Doxymed® in healthy broiler chickens after oral administration of both products in a dose of 20 mg doxycycline/kg.b.wt. Materials and Methods: Twenty broiler chickens were divided into two groups. The first group was designed to study the pharmacokinetics of Doxysol, while the 2nd group was designed to study the pharmacokinetics of Doxymed. Each broiler chickens in both groups were injected intravenously with 20 mg doxycycline/kg.b.wt. Blood samples were obtained from the wing vein and collected immediately before and at 5, 15, 30 minute, 1, 2, 4, 6, 8, 12 and 24 hours after a single intravenous or oral administration. Results: Doxycycline in both products obeyed a two compartments open model following I.V. injection in a dose of 20 mg/kg.b.wt. The disposition kinetics of Doxysol® and Doxymed® following oral administration of 20 mg doxycycline base/kg.b.wt. revealed that the maximum blood concentration [Cmax.] were 4.70 and 4.65 μg/ml and attained at [tmax.] of 1.30 and 1.40 hours, respectively. Doxycycline in Doxysol® and Doxymed® was eliminated with half-lives [t0.5(β)] equal to 1.98 and 2.31 hours, respectively. The mean systemic bioavailability of doxycycline in Doxysol® and Doxymed® after oral administration in healthy chickens was 92.57 and 88.21%, respectively. Conclusion: Doxymed® is bioequivalent to Doxysol® since Cmax test/Cmax reference and AUCtest/AUCreference ratios were 99% and 90%, respectively.
文摘Background: Telmisartan is a highly variable drug which is used to treat hypertension. This study compared to compare the bioavailability of two 40 mg Telmisartan tablets in adult and healthy Bangladeshi subjects. Materials and Method: This study was open label, randomized, laboratory blind, single dose, three periods, two treatments, three-sequence, partial-replicate, crossover and comparative oral bioavailability study. In this study, 18 Bangladeshi subjects were enrolled and 17 subjects were completed. Serial blood samples were collected up to 96 hours following drug administration. By using Liquid Chromatography Mass Spectrometry (LC-MS/MS) method, plasma concentrations of Telmisartan were determined. Results: The two formulations of Telmisartan were considered bioequivalent if 90% Confidence Interval (CI) fall within the range of 80.00% - 125.00% for AUC parameters and reference-scaled-average bioequivalence of 69.84% - 143.19% for C<sub>max</sub>. The 90% Confidence Interval for C<sub>max</sub>, AUC<sub>0-t</sub> & AUC<sub>0-∞</sub> was found 84.88% - 107.79%, 89.76% - 109.55%, and 91.20% - 114.52%, respectively. Conclusion: According to rate and extent of absorption with the single dose of Reference Product (R): Micardis<sup><sup><sup>®</sup></sup></sup> 40 mg Tablet, under fasting conditions, a single dose of Telmisartan 40 mg Tablet is bioequivalent.
文摘A method for the determination of carvedilol in human plasma was developed using a high-performance liquid chromatography with tandem mass spectrometer (HPLC-MS/MS). Plasma samples were deproteinized using acetonitrile and the supernatant was directly injected onto the HPLC column without any preparative steps. Chromatography was performed on a reversed-phase (C18) column with isocratic mobile phase for 2 min. The calibration curve was linear over the range of 2 to100 ng/ml (R2 > 0.9998) and the lower limit of quantitation (LLOQ) was 2 ng/ml. This method showed acceptable precision and accuracy, good recovery from the plasma matrix, and stability during the analytical procedures. When its application to the bioequivalence test of two carvedilol 25 mg tablet formulations in male healthy 28 volunteers, this validated analysis method was appropriate resulting in the bioequivalence of two formulations: no statistically significant difference was observed between the logarithmic transformed area under curve (AUC) and maximum plasma concentration (Cmax) values of the two formulations. The 90% confidence interval for the ratio of the above mentioned two parameters were within the bioequivalence limit of 0.80-1.25. These results suggested that the HPLC-MS/MS analysis method developed was suitable for the carvedilol analysis in human plasma.
基金supported by the National Natural Science Foundation of China(No.81102499)Hunan Science and Technology Project(No.2011SK3261)+1 种基金the Fundamental Research Funds for the Central Universities of Central South University(No.2014zzts313)the support from Chongqing Fu An Pharmaceutical Group Qingyutang Pharmaceutical Co.,Ltd
文摘The aim of this study was to apply the reference-scaled average bioequivalence(RSABE)approach to evaluate the bioequivalence of 2 formulations of agomelatine,and to investigate the pharmacokinetic properties of agomelatine in Chinese healthy male subjects.This was performed in a single-dose,randomized-sequence,open-label,four-way crossover study with a one-day washout period between doses.Healthy Chinese males were randomly assigned to receive 25 mg of either the test or reference formulation.The formulations were considered bioequivalent if 90% confidence intervals(CIs)for the log-transformed ratios and ratio of geometric means(GMR)of AUC and C_(max) of agomelatine were within the predetermined bioequivalence range based on RSABE method.Results showed that both of the90% CIs for the log-transformed ratios of AUC and C_(max) of 7-desmethyl-agomelatine and 3-hydroxyagomelatine were within the predetermined bioequivalence range.The 90% CIs for natural logtransformed ratios of C_(max) ,AUC_(0–t)and AUC_(0–∞) of agomelatine(104.42–139.86,101.33–123.83 and97.90–117.94)were within the RSABE acceptance limits,and 3-hydroxy-agomelatine(105.55–123.03,101.95–109.10 and 101.72–108.70)and 7-desmethyl-agomelatine(104.50–125.23,102.36–111.50 and101.62–110.64)were within the FDA bioequivalence definition intervals(0.80–1.25 for AUC and0.75–1.33 for C_(max)).The RSABE approach was successful in evaluating the bioequivalence of these two formulations.
