The aim of this study was to investigate the effect of high-pressure homogenization on the droplet size and physical stability of different formulations of pectin–zein stabilized rice bran oil emulsions. The obtained...The aim of this study was to investigate the effect of high-pressure homogenization on the droplet size and physical stability of different formulations of pectin–zein stabilized rice bran oil emulsions. The obtained emulsions, both before and after passing through highpressure homogenizer, were subjected to stability test under environmental stress conditions,that is, temperature cycling at 4 °C/40 °C for 6 cycles and centrifugal test at 3000 rpm for 10 min. Applying high-pressure homogenization after mechanical homogenization caused only a small additional decrease in emulsion droplet size. The droplet size of emulsions was influenced by the type of pectin used;emulsions using high methoxy pectin(HMP) were smaller than that using low methoxy pectin(LMP). This is due to a greater emulsifying property of HMP than LMP. The emulsions stabilized by HMP–zein showed good physical stability with lower percent creaming index than those using LMP, both before and after passing through high-pressure homogenizer. The stability of emulsions after passing through high-pressure homogenizer was slightly higher when using higher zein concentration, resulting from stronger pectin–zein complexes that could rearrange and adsorb onto the emulsion droplets.展开更多
2,3-Dihydro-2-aryl-4(1H)-quinazolinones were prepared in good yields via condensation of o-aminobenzamide with aldehydes promoted by a catalytic amount of Sc(OTf)_3 under mild conditions.
We investigated the delivery of drugs to the posterior segment of the eye by non-invasive topical instillation using submicron-sized poly(D,L-lactide-co-glycolide)(PLGA) nanoparticles(NPs). Surface-modified PLGA NPs w...We investigated the delivery of drugs to the posterior segment of the eye by non-invasive topical instillation using submicron-sized poly(D,L-lactide-co-glycolide)(PLGA) nanoparticles(NPs). Surface-modified PLGA NPs were developed to improve the drug delivery efficiency to the retina and were administered as topical eye drops to mice. Chitosan(CS) and glycol chitosan(GCS), which are mucoadhesive polymers, and polysorbate 80(P80) were used as surface modifiers, and have been reported to increase the association of NPs with cells.Coumarin-6 was used as a model drug and fluorescent marker, and after ocular administration of PLGA NP eye drops, the fluorescence intensity of coumarin-6 was observed in the retina. The fluorescence image analysis indicated that there are several possible routes to the retina and fates of PLGA NPs in ocular tissue, and that these pathways involved the corneal,non-corneal, or uveal routes. Delivery to the mouse retina segments after topical administration was increased by surface modification with CS, GCS, or P80. Surface-modified PLGA NPs are a promising method for retinal drug delivery via topical instillation.展开更多
We previously determined 'Tableting properties' by using a multi-functional single-punch tablet press(GTP-1). We proposed plotting 'Compactability' on the x-axis against'Manufacturability' on t...We previously determined 'Tableting properties' by using a multi-functional single-punch tablet press(GTP-1). We proposed plotting 'Compactability' on the x-axis against'Manufacturability' on the y-axis to allow visual evaluation of 'Tableting properties'. Various types of tableting failure occur in commercial drug production and are influenced by the amount of lubricant used and the shape of the punch. We used the GTP-1 to measure'Tableting properties' with different amounts of lubricant and compared the results with those of tableting on a commercial rotary tableting machine. Tablets compressed with a small amount of lubricant showed bad 'Manufacturability', leading to sticking of powder on punches.We also tested various punch shapes. The GTP-1 correctly predicted the actual tableting results for all punch shapes. With punches that were more likely to cause tableting failure, our system predicted the effects of lubricant quantity in the tablet formulation and the occurrence of sticking in the rotary tableting machine.展开更多
The purpose of this study was to design a submicron-sized liposomal non-steroidal antiinflammatory drug(NSAID)preparation that targets the retina via topical instillation of eye drops.Bromfenac(BRF)-loaded liposomes w...The purpose of this study was to design a submicron-sized liposomal non-steroidal antiinflammatory drug(NSAID)preparation that targets the retina via topical instillation of eye drops.Bromfenac(BRF)-loaded liposomes were prepared using the calcium acetate gradient method.Liposome sizes and encapsulation efficiencies were optimized by screening several liposome formulations of lipid,drug concentration,and buffer solution.BRF entrapment efficiency was greater than 90%using this method,and was low using conventional hydration methods.High initial BRF loading using the pH gradient method caused aggregation of liposomes.To circumvent aggregation,the negatively charged lipid dicetylphosphate was incorporated into liposomes,which formed anion layer preventing coalescence.Release of BRF from liposomes was sustained for several hours depending on lipid concentration,inner water phase,initial drug amounts,and surface properties.Surface modification with chitosan(CS),a mucoadhesive cationic polymer,was achieved using electrostatic interactions of negatively charged liposomes.The optimal concentration of CS for evasion of liposome aggregation was 0.15%.展开更多
We previously determined "Tableting properties" by using a multi-functional single-punch tablet press(GTP-1). We plotted "Compactability" on the x-axis against "Manufacturability"on the y...We previously determined "Tableting properties" by using a multi-functional single-punch tablet press(GTP-1). We plotted "Compactability" on the x-axis against "Manufacturability"on the y-axis to allow visual evaluation of "Tableting properties". Here, we examined whether this evaluation method can be used in the formulation design of tablets prepared by wet granulation. We used the GTP-1 to measure "Tableting properties" with different amounts of binder, disintegrant, and lubricant, and compared the results with those of tableting on a commercial rotary tableting machine. Tableting failures(capping and binding in particular) occurred when samples that had been evaluated as having poor "Compactability" or"Manufacturability" on the GTP-1 were compressed on the rotary tableting machine. Thus,our evaluation method predicted tableting failure at the commercial scale. The method will prove useful for scaling up production.展开更多
A Yb(OTf)_3-catalyzed approach for the synthesis of pyrroles under solvent-free conditions was achieved,which could afford the desired products with yields ranged from moderate to excellent.
This investigation was undertaken to enhance the solubility and consequent antibacterial activity of cefuroxime axetil (CA), a </span><i><span style="font-family:Verdana;">β</span>&l...This investigation was undertaken to enhance the solubility and consequent antibacterial activity of cefuroxime axetil (CA), a </span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-lactamase-stable broad spectrum second generation cephalosporin through solid dispersion (SD) technique. For this purpose, CA loaded SDs (CSDs) were prepared by solvent evaporation method using different concentrations of microcrystalline cellulose (MCC) as carrier. The CSDs were characterized by </span><i><span style="font-family:Verdana;">in-vitro</span></i><span style="font-family:Verdana;"> dissolution study, thermal analysis (DSC), crystallinity (PXRD), interactions (FTIR) and morphology (SEM). Among the formulations, CSD-2 showed the highest dissolution rate which was 2.59-fold higher than pure CA with a drug-carrier (CA: MCC) ratio of 1:3. Enhanced dissolution rate was attributed to conversion of drug from crystalline to amorphous state during preparation of SDs, which was validated by DSC, PXRD, FTIR and SEM analyses. Antibacterial activity of CSD-2 against </span><i><span style="font-family:Verdana;">Staphylococcus aureus</span></i><span style="font-family:Verdana;"> (ATCC 25923) and </span><i><span style="font-family:Verdana;">Escherichia coli</span></i><span style="font-family:Verdana;"> (ATCC 25922) showed 1.94- and 6.75-fold higher relative zone of inhibition (RZOI), respectively than pure CA. CSD-2 has been found to be the most effective optimized formulation in terms of both enhanced dissolution rate and antibacterial activity. Thus, it can be an effective alternative to conventional dosage forms of CA. However, further investigations are needed to validate its pharmacokinetic properties, </span><i><span style="font-family:Verdana;">in-vivo </span></i><span style="font-family:Verdana;">antibacterial efficacy and safety before recommending as a novel展开更多
A series of(Z)-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis(tri...A series of(Z)-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis(trichloromethyl) carbonate(BTC, triphosgene) and DMF.A possible mechanism was also proposed,where sequential ring-opening,halogenation and elimination reactions were involved.展开更多
基金financially supported by the Research and Development Institute, Silpakorn University
文摘The aim of this study was to investigate the effect of high-pressure homogenization on the droplet size and physical stability of different formulations of pectin–zein stabilized rice bran oil emulsions. The obtained emulsions, both before and after passing through highpressure homogenizer, were subjected to stability test under environmental stress conditions,that is, temperature cycling at 4 °C/40 °C for 6 cycles and centrifugal test at 3000 rpm for 10 min. Applying high-pressure homogenization after mechanical homogenization caused only a small additional decrease in emulsion droplet size. The droplet size of emulsions was influenced by the type of pectin used;emulsions using high methoxy pectin(HMP) were smaller than that using low methoxy pectin(LMP). This is due to a greater emulsifying property of HMP than LMP. The emulsions stabilized by HMP–zein showed good physical stability with lower percent creaming index than those using LMP, both before and after passing through high-pressure homogenizer. The stability of emulsions after passing through high-pressure homogenizer was slightly higher when using higher zein concentration, resulting from stronger pectin–zein complexes that could rearrange and adsorb onto the emulsion droplets.
基金We are grateful to the National Basic Research Program （No. 2003CB114402）；the National Natural Science Foundation of China （Nos. 20476098 and 20676123） ；Wenzhou University Post-graduate Innovation Foundation （No. YCX0515） for financial support.
文摘2,3-Dihydro-2-aryl-4(1H)-quinazolinones were prepared in good yields via condensation of o-aminobenzamide with aldehydes promoted by a catalytic amount of Sc(OTf)_3 under mild conditions.
基金supported by JSPS KAKENHI Grant Number JP16K18948
文摘We investigated the delivery of drugs to the posterior segment of the eye by non-invasive topical instillation using submicron-sized poly(D,L-lactide-co-glycolide)(PLGA) nanoparticles(NPs). Surface-modified PLGA NPs were developed to improve the drug delivery efficiency to the retina and were administered as topical eye drops to mice. Chitosan(CS) and glycol chitosan(GCS), which are mucoadhesive polymers, and polysorbate 80(P80) were used as surface modifiers, and have been reported to increase the association of NPs with cells.Coumarin-6 was used as a model drug and fluorescent marker, and after ocular administration of PLGA NP eye drops, the fluorescence intensity of coumarin-6 was observed in the retina. The fluorescence image analysis indicated that there are several possible routes to the retina and fates of PLGA NPs in ocular tissue, and that these pathways involved the corneal,non-corneal, or uveal routes. Delivery to the mouse retina segments after topical administration was increased by surface modification with CS, GCS, or P80. Surface-modified PLGA NPs are a promising method for retinal drug delivery via topical instillation.
基金the National Basic Research Program of China 973 Program(No.2003CB114400)the National Natural Science Foundation of China(No.20476098)for financial support.(No.20676123)
文摘We previously determined 'Tableting properties' by using a multi-functional single-punch tablet press(GTP-1). We proposed plotting 'Compactability' on the x-axis against'Manufacturability' on the y-axis to allow visual evaluation of 'Tableting properties'. Various types of tableting failure occur in commercial drug production and are influenced by the amount of lubricant used and the shape of the punch. We used the GTP-1 to measure'Tableting properties' with different amounts of lubricant and compared the results with those of tableting on a commercial rotary tableting machine. Tablets compressed with a small amount of lubricant showed bad 'Manufacturability', leading to sticking of powder on punches.We also tested various punch shapes. The GTP-1 correctly predicted the actual tableting results for all punch shapes. With punches that were more likely to cause tableting failure, our system predicted the effects of lubricant quantity in the tablet formulation and the occurrence of sticking in the rotary tableting machine.
文摘The purpose of this study was to design a submicron-sized liposomal non-steroidal antiinflammatory drug(NSAID)preparation that targets the retina via topical instillation of eye drops.Bromfenac(BRF)-loaded liposomes were prepared using the calcium acetate gradient method.Liposome sizes and encapsulation efficiencies were optimized by screening several liposome formulations of lipid,drug concentration,and buffer solution.BRF entrapment efficiency was greater than 90%using this method,and was low using conventional hydration methods.High initial BRF loading using the pH gradient method caused aggregation of liposomes.To circumvent aggregation,the negatively charged lipid dicetylphosphate was incorporated into liposomes,which formed anion layer preventing coalescence.Release of BRF from liposomes was sustained for several hours depending on lipid concentration,inner water phase,initial drug amounts,and surface properties.Surface modification with chitosan(CS),a mucoadhesive cationic polymer,was achieved using electrostatic interactions of negatively charged liposomes.The optimal concentration of CS for evasion of liposome aggregation was 0.15%.
文摘We previously determined "Tableting properties" by using a multi-functional single-punch tablet press(GTP-1). We plotted "Compactability" on the x-axis against "Manufacturability"on the y-axis to allow visual evaluation of "Tableting properties". Here, we examined whether this evaluation method can be used in the formulation design of tablets prepared by wet granulation. We used the GTP-1 to measure "Tableting properties" with different amounts of binder, disintegrant, and lubricant, and compared the results with those of tableting on a commercial rotary tableting machine. Tableting failures(capping and binding in particular) occurred when samples that had been evaluated as having poor "Compactability" or"Manufacturability" on the GTP-1 were compressed on the rotary tableting machine. Thus,our evaluation method predicted tableting failure at the commercial scale. The method will prove useful for scaling up production.
基金the National Key Technology R&D Program(No.2007BAI34B00)the National Natural Science Foundation of China(No.20876147 and 20676123)the Natural Science Foundation of Zhejiang Province(No.Y4080107) for financial support.
文摘A Yb(OTf)_3-catalyzed approach for the synthesis of pyrroles under solvent-free conditions was achieved,which could afford the desired products with yields ranged from moderate to excellent.
文摘This investigation was undertaken to enhance the solubility and consequent antibacterial activity of cefuroxime axetil (CA), a </span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-lactamase-stable broad spectrum second generation cephalosporin through solid dispersion (SD) technique. For this purpose, CA loaded SDs (CSDs) were prepared by solvent evaporation method using different concentrations of microcrystalline cellulose (MCC) as carrier. The CSDs were characterized by </span><i><span style="font-family:Verdana;">in-vitro</span></i><span style="font-family:Verdana;"> dissolution study, thermal analysis (DSC), crystallinity (PXRD), interactions (FTIR) and morphology (SEM). Among the formulations, CSD-2 showed the highest dissolution rate which was 2.59-fold higher than pure CA with a drug-carrier (CA: MCC) ratio of 1:3. Enhanced dissolution rate was attributed to conversion of drug from crystalline to amorphous state during preparation of SDs, which was validated by DSC, PXRD, FTIR and SEM analyses. Antibacterial activity of CSD-2 against </span><i><span style="font-family:Verdana;">Staphylococcus aureus</span></i><span style="font-family:Verdana;"> (ATCC 25923) and </span><i><span style="font-family:Verdana;">Escherichia coli</span></i><span style="font-family:Verdana;"> (ATCC 25922) showed 1.94- and 6.75-fold higher relative zone of inhibition (RZOI), respectively than pure CA. CSD-2 has been found to be the most effective optimized formulation in terms of both enhanced dissolution rate and antibacterial activity. Thus, it can be an effective alternative to conventional dosage forms of CA. However, further investigations are needed to validate its pharmacokinetic properties, </span><i><span style="font-family:Verdana;">in-vivo </span></i><span style="font-family:Verdana;">antibacterial efficacy and safety before recommending as a novel
基金the National Natural Science Foundation of China(Nos.20806073 and 20876147)the National Key Technology Research and Development Program(No.2007BAI34B06) for financial support
文摘A series of(Z)-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis(trichloromethyl) carbonate(BTC, triphosgene) and DMF.A possible mechanism was also proposed,where sequential ring-opening,halogenation and elimination reactions were involved.
基金supported by the National Basic Research Program(973)of China(No.2012CB725202)the National High-Tech R&D Program(863)of China(No.2011AA02A211)+4 种基金the National Natural Science Foundation of China(No.21276110)the Fundamental Research Funds for the Central Universities(Nos.JUSRP51306A and JUSRP11545)the National 111 Project of China’s Higher Education(No.111-2-06)the Program of the Key Laboratory of Industrial Biotechnology,Ministry of Education,China(No.KLIB-KF201406)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
文摘目的:获得一株高产雄甾-4-烯-3,17-二酮(AD)的Mycobacterium neoaurum突变株。创新点:获得了一株3-甾酮-Δ1-脱氢酶(KSDD)酶活缺陷型的高产AD的诱变菌株Mycobacterium neoaurum ZADF-4,并采用菌落显色法筛选KSDD酶活缺陷型M.neoaurum突变株。方法:(1)诱变方法:采用常压室温等离子体(ARTP)诱变技术来处理出发菌株M.neoaurum ZAD。ARTP诱变条件如下:功率40 W,气流量12.5 L/min,辐射距离1 cm,样品体积10μl,辐射时间为60、90、120、150和180 s;致死率统计优化后,最适辐射时间为150 s,致死率为90%~96%。(2)筛选方法:将ARTP诱变处理后的菌株点种在硝酸纤维滤膜上,30°C培养2 d,然后将长有菌落的滤膜小心取出并漂浮在4 mg/ml二氯靛酚(DCPIP)溶液(0.1 mmol/L磷酸缓冲液p H 7.0),30°C培养1 d直到全部菌落染成蓝色。然后将该滤膜取出,漂浮在250 mmol/L AD溶液(2%甲醇和50 mmol/L Tris p H 7.0缓冲液),室温放置15 min左右,观察菌落颜色变化。KSDD在底物AD存在时会脱氢产生雄甾-1,4-二烯-3,17-二酮(ADD)和H+,H+可以使被DCPIP染成蓝色的菌株褪色。因此,酶活缺陷型的菌株会仍保持蓝色,而酶活高的菌株会褪色为黄色(图3)。(3)对获得的潜在的高产AD菌株进行进一步的酶活检测以及产量验证,以期获得最优的突变株。结论:获得了4株具有潜在的高产AD能力的菌株,其中,最优的突变株ZADF-4的KSDD酶活相较于出发菌株ZAD下降了81.2%(图4),活性胶也证明其KSDD酶活相较于出发菌株下降明显(图5)。薄层色谱法(TLC)和高效液相色谱法(HPLC)实验证明突变株ZADF-4中,AD的产量有了明显的提高(图6和图7),提高到了(6.28±0.11)g/L,AD/ADD提高到8:1,AD的摩尔产率达到60.3%(表1)。对出发菌株ZAD和突变株ZADF-4的ksdd基因进行克隆和序列比对,发现ZADF-4的ksdd序列在5'端缺失9个核苷酸(atgttctac),导致3个氨基酸(MFY)的缺失;还发生了两个点突变,其中一个是无义突变(g.15a>6t),另一个是有义突变(g.413c>404t),并引起了相应位置上的氨基酸变化(p.138S>135L)。上述的基因突变及其引起的氨基酸序列的变化可能是引起M.neoaurum ZADF-4中KSDD酶活降低及AD产量提高的主要原因。
