摘要
建立利培酮(RIP)和其活性代谢物9-羟基利培酮代谢动力学模型,并考察其在健康男性志愿者中的药动学特征。22名健康男性志愿者单剂量口服利培酮2 mg,在服药前及服药后96 h内的不同时间点取血。HPLC-MS法测定RIP和9-羟基利培酮的血药浓度;依据RIP和9-羟基利培酮的T1/2确定志愿者中CYP2D6快代谢(EM)、中代谢(IM)和慢代谢(PM)型的分布,相似转换法(similarity transformation)进行模型结构鉴别,依据鉴别结果进行模型修正;加权最小二乘法进行模型参数估算;以Monte Carlo法产生的模拟数据进行模型验证,评估模型参数求算的准确性。22名健康男性志愿者中EM型18名,IM型4名;模型鉴别结果提示假设模型不可整体鉴别,当获知RIP代谢为9-羟基利培酮的转换分数时,模型参数均可求算;模型对于EM型和IM型RIP和9-羟基利培酮血药浓度经时过程和主要药动学参数AUC0-t,Cmax和Tmax预测效果均较好。RIP代谢为9-羟基利培酮的转换速率常数EM型为(0.12±0.08)h-1,IM型为(0.014±0.007)h-1,RIP的消除速率常数EM型为(0.25±0.18)h-1,IM型为(0.05±0.23)h-1。模型验证结果提示:参数估算值的均值与实际值较为接近;大多数参数的平均预测误差均在±15%内。模型具有代表性,不同CYP2D6表型者RIP代谢药动学参数差异较大,可为RIP进一步临床研究打下基础。同时模型结构鉴别可为复杂药动学模型的参数求算和实验设计提供有力的帮助。
To develop a parent-metabolite pharmacokinetic model for risperidone （RIP） and its major active metabolite （9-hydroxyrisperidone） and investigate their pharmacokinetics characteristics in healthy male volunteers, twenty-two healthy volunteers were orally given a single dose of 2 mg RIP. Plasma samples were collected in the period of 96 hours and concentrations of RIP and 9-hydroxyrisperidone were measured by a validated HPLC/MS method. CYP2D6 phenotypes were identified by the T1/2 of RIP and 9-hydroxyrisperidone according to the literature. Model structure identifiability analysis was performed by the similarity transformation approach to investigate whether the unknown parameters of the proposed model could be estimated from the designed experiment. Pharmacokinetics parameters were estimated using weighted least squares method, and the final pharmacokinetics model were tested and evaluated by Monte Carlo simulation. Eighteen volunteers were phenotyped as extensive metabolizers （EM） and four volunteers were identified as intermediate metabolizers （IM） The final model included central and peripheral compartment for both parent （RIP） and metabolite （9-hydroxyrisperidone） respectively. Model structure identifiability analysis indicated that the proposed model was local identifiable. However, if the ratio of RIP converted to 9-hydroxyrisperidone was assumed to be 32% in EM, and 22% in IM, the model could be globally identifiable. The predicted time-concentration curve and AUC0-1, Cmax, Tmax of RIP and 9-hydroxyrisperidone estimated by the established model were in agreement with the observations and noncompartment analysis. Rate constant of RIP conversion to 9-hydroxyrisperidone was （0. 12 ±0. 08） h^-1 and （0. 014 ±0. 007） h ^-1 for EM and IM, respectively. Elimination rate constants of RIP were （0. 25± 0. 18） and （0.05 ±0.23） h^-1 for EM and IM, respectively. Model validation result showed that all parameters derived from the concentration data fitted well with the theoretical value, with mean prediction error of most PK parameter within ＋ 15%. The established model well defined the disposition of RIP and 9-hydroxyrisperidone simultaneously and showed large inter-individual pharmacokinetics variation in different CYP2D6 phenotype. The model also provide a useful approach to characterize pharmacokinetics of other parent-metabolite drugs.
出处
《药学学报》
CAS
CSCD
北大核心
2007年第6期631-638,共8页
Acta Pharmaceutica Sinica
