This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and ...This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and propofol（10 mg/kg） was administrated intravenously. Artery blood samples were collected at various time points after injection, and plasma concentrations of propofol were measured. Pharmacokinetic modeling was performed using Win Nonlin software. Propofol TCI within the acquired parameters integrated was conducted to achieve different anesthetic depths in rabbits, monitored by narcotrend. The pharmacodynamics was analyzed using a sigmoidal inhibitory maximal effect model for narcotrend index（NI） versus effect-site concentration. The results showed the pharmacokinetics of propofol in Japanese white rabbits was best described by a two-compartment model. The target plasma concentrations of propofol required at light anesthetic depth was 9.77±0.23 μg/m L, while 12.52±0.69 μg/m L at deep anesthetic depth. NI was 76.17±4.25 at light anesthetic depth, while 27.41±5.77 at deep anesthetic depth. The effect-site elimination rate constant（ke0） was 0.263/min, and the propofol dose required to achieve a 50% decrease in the NI value from baseline was 11.19 μg/m L（95% CI, 10.25–13.67）. Our results established a new propofol TCI animal model and proved the model controlled the anesthetic depth accurately and stably in rabbits. The study provides a powerful method for exploring general anesthetic mechanisms at different anesthetic depths in vivo.展开更多
Purpose: BupredermTM-Buprenorphine transdermal delivery system (BTDS) was developed for the treatment of post-operative and chronic pains. This study examined the relationship between the plasma concentration of bupre...Purpose: BupredermTM-Buprenorphine transdermal delivery system (BTDS) was developed for the treatment of post-operative and chronic pains. This study examined the relationship between the plasma concentration of buprenorphine and its analgesic effect (tail flick test) in order to assess the usefulness of pharmacokinetic-pharmacodynamic (PK-PD) modeling in describing this relationship. Methods: After patch application, plasma concentrations of bu- prenorphine in mice were measured for 72 hours with a validated LC/MS/MS system, and the analgesic effects were assessed by tail flick test for the period of 24 hours. A modified two- compartment open model was used to explain the PK properties of BTDS, and the PD model was characterized by slow receptor binding. Results: The peak buprenorphine level in plasma was achieved at 1-24 h and the effective therapeutic drug concentration was maintained for 72 hours. BupredermTM induced prolongation of tail-flick latency in a dose and time dependent manner. Maximum analgesic effect was attained at 3-6 h and was maintained for 24 h after patch application. Counter-clockwise hysteresis between the plasma concentration and the analgesic efficacy of BTDS was observed after BupredermTM application, indicating there was a delay between plasma concentrations and the effect observed. From the developed PK-PD model, Kd values (0.69-0.82 nM) that were derived from the pharmacodynamic parameters (Kon and Koff) are similar to the reported values (Kd = 0.76 ± 0.14 nM). Good agreement between the predicted and observed values was noted for the rate of change in analgesic effect data (R2 = 0.822, 0.852 and 0.774 for 0.24, 0.8 and 2.4 mg/patch, respectively). Conclusions: The established PK- PD model successfully described the relationship between plasma concentration of buprenorphine and its analgesic efficacy measured by the tail flick test. Our model might be useful in estimation and prediction of onset, magnitude and time course of concentration and pharmacological effects of BTDS and will be useful to simulate PK-PD profiles with clinical regimens.展开更多
Various drugs are used to maintain normoglycemia in subjects with type 2 diabetes mellitus.The combination of the drugs from different classes in one single tablet may enhance the effectiveness of the anti-diabetic dr...Various drugs are used to maintain normoglycemia in subjects with type 2 diabetes mellitus.The combination of the drugs from different classes in one single tablet may enhance the effectiveness of the anti-diabetic drugs.To investigate the impact of combining drugs on the glucose regulation of subjects with type 2 diabetes,we propose a pharmacokinetic/pharmacodynamics(PK/PD)mathematical modeling approach for a combination of metformin and vildagliptin drugs.In the proposed modeling approach,two separate PK models representing oral administration of metformin and vildagliptin for diabetic subjects are interconnected to a PD model comprising a detailed compartmental physiological model representing the regulatory effect of insulin,incretins and glucagon hormones on glucose concentration in a human body.The impact of doses of individual drugs and their combination on the blood glucose concentration of a group of type 2 diabetic subjects is investigated.It is indicated that while administration of individual drugs reduces the blood glucose levels,since they have separate mechanisms of action,combining them synergizes lowering the blood glucose levels.展开更多
With the interdisciplinary development of multiple disciplines,mathematical models play a role as a bridge in the research process of Chinese herbal compounds,which can make full use of the interrelationships of knowl...With the interdisciplinary development of multiple disciplines,mathematical models play a role as a bridge in the research process of Chinese herbal compounds,which can make full use of the interrelationships of knowledge,making the research and use of Chinese herbal compounds from complex and cumbersome to simple.This paper reviewed the research and application of mathematical models in the production and preparation,pharmacodynamics,pharmacokinetics and other aspects of Chinese herbal compound prescriptions,providing a theoretical basis for the development of the modern Chinese medicine industry.展开更多
数学建模与模拟(modeling and simulation,M&S)是药代动力学(药动学)与药效动力学(药效学)中重要的定量研究方法,在研究药物的处置和作用的机理、治疗药物监测及新药开发中发挥越来越重要的作用。但目前国内该领域的研究尚不多,有...数学建模与模拟(modeling and simulation,M&S)是药代动力学(药动学)与药效动力学(药效学)中重要的定量研究方法,在研究药物的处置和作用的机理、治疗药物监测及新药开发中发挥越来越重要的作用。但目前国内该领域的研究尚不多,有待大力发展。另外,M&S涉及的数学知识较多,造成研究者阅读文献和实际应用的困难。本系列文章简要介绍M&S的一些基本概念及重要原理,供读者参考。本部分着重说明了数学模型的定义、特点、分类,以及建模解决实际问题的基本思路。展开更多
数学建模与模拟(modeling and simulation,M&S)是药代动力学(药动学)与药效动力学(药效学)中重要的定量研究方法,在研究药物的处置和作用的机理、治疗药物监测及新药开发中发挥越来越重要的作用。但目前国内该领域的研究尚不多,有...数学建模与模拟(modeling and simulation,M&S)是药代动力学(药动学)与药效动力学(药效学)中重要的定量研究方法,在研究药物的处置和作用的机理、治疗药物监测及新药开发中发挥越来越重要的作用。但目前国内该领域的研究尚不多,有待大力发展。另外,M&S涉及的数学知识较多,造成研究者阅读文献和实际应用的困难。本系列文章简要介绍M&S的一些基本概念及重要原理,供读者参考。本部分着重讨论模型开发过程及拟合优度标准的有关问题。展开更多
基金supported by a grant from Shenzhen Baoan Hospital Affiliated to Southern Medical University
文摘This study aimed to establish a new propofol target-controlled infusion（TCI） model in animals so as to study the general anesthetic mechanism at multi-levels in vivo. Twenty Japanese white rabbits were enrolled and propofol（10 mg/kg） was administrated intravenously. Artery blood samples were collected at various time points after injection, and plasma concentrations of propofol were measured. Pharmacokinetic modeling was performed using Win Nonlin software. Propofol TCI within the acquired parameters integrated was conducted to achieve different anesthetic depths in rabbits, monitored by narcotrend. The pharmacodynamics was analyzed using a sigmoidal inhibitory maximal effect model for narcotrend index（NI） versus effect-site concentration. The results showed the pharmacokinetics of propofol in Japanese white rabbits was best described by a two-compartment model. The target plasma concentrations of propofol required at light anesthetic depth was 9.77±0.23 μg/m L, while 12.52±0.69 μg/m L at deep anesthetic depth. NI was 76.17±4.25 at light anesthetic depth, while 27.41±5.77 at deep anesthetic depth. The effect-site elimination rate constant（ke0） was 0.263/min, and the propofol dose required to achieve a 50% decrease in the NI value from baseline was 11.19 μg/m L（95% CI, 10.25–13.67）. Our results established a new propofol TCI animal model and proved the model controlled the anesthetic depth accurately and stably in rabbits. The study provides a powerful method for exploring general anesthetic mechanisms at different anesthetic depths in vivo.
文摘Purpose: BupredermTM-Buprenorphine transdermal delivery system (BTDS) was developed for the treatment of post-operative and chronic pains. This study examined the relationship between the plasma concentration of buprenorphine and its analgesic effect (tail flick test) in order to assess the usefulness of pharmacokinetic-pharmacodynamic (PK-PD) modeling in describing this relationship. Methods: After patch application, plasma concentrations of bu- prenorphine in mice were measured for 72 hours with a validated LC/MS/MS system, and the analgesic effects were assessed by tail flick test for the period of 24 hours. A modified two- compartment open model was used to explain the PK properties of BTDS, and the PD model was characterized by slow receptor binding. Results: The peak buprenorphine level in plasma was achieved at 1-24 h and the effective therapeutic drug concentration was maintained for 72 hours. BupredermTM induced prolongation of tail-flick latency in a dose and time dependent manner. Maximum analgesic effect was attained at 3-6 h and was maintained for 24 h after patch application. Counter-clockwise hysteresis between the plasma concentration and the analgesic efficacy of BTDS was observed after BupredermTM application, indicating there was a delay between plasma concentrations and the effect observed. From the developed PK-PD model, Kd values (0.69-0.82 nM) that were derived from the pharmacodynamic parameters (Kon and Koff) are similar to the reported values (Kd = 0.76 ± 0.14 nM). Good agreement between the predicted and observed values was noted for the rate of change in analgesic effect data (R2 = 0.822, 0.852 and 0.774 for 0.24, 0.8 and 2.4 mg/patch, respectively). Conclusions: The established PK- PD model successfully described the relationship between plasma concentration of buprenorphine and its analgesic efficacy measured by the tail flick test. Our model might be useful in estimation and prediction of onset, magnitude and time course of concentration and pharmacological effects of BTDS and will be useful to simulate PK-PD profiles with clinical regimens.
文摘Various drugs are used to maintain normoglycemia in subjects with type 2 diabetes mellitus.The combination of the drugs from different classes in one single tablet may enhance the effectiveness of the anti-diabetic drugs.To investigate the impact of combining drugs on the glucose regulation of subjects with type 2 diabetes,we propose a pharmacokinetic/pharmacodynamics(PK/PD)mathematical modeling approach for a combination of metformin and vildagliptin drugs.In the proposed modeling approach,two separate PK models representing oral administration of metformin and vildagliptin for diabetic subjects are interconnected to a PD model comprising a detailed compartmental physiological model representing the regulatory effect of insulin,incretins and glucagon hormones on glucose concentration in a human body.The impact of doses of individual drugs and their combination on the blood glucose concentration of a group of type 2 diabetic subjects is investigated.It is indicated that while administration of individual drugs reduces the blood glucose levels,since they have separate mechanisms of action,combining them synergizes lowering the blood glucose levels.
文摘With the interdisciplinary development of multiple disciplines,mathematical models play a role as a bridge in the research process of Chinese herbal compounds,which can make full use of the interrelationships of knowledge,making the research and use of Chinese herbal compounds from complex and cumbersome to simple.This paper reviewed the research and application of mathematical models in the production and preparation,pharmacodynamics,pharmacokinetics and other aspects of Chinese herbal compound prescriptions,providing a theoretical basis for the development of the modern Chinese medicine industry.
文摘数学建模与模拟(modeling and simulation,M&S)是药代动力学(药动学)与药效动力学(药效学)中重要的定量研究方法,在研究药物的处置和作用的机理、治疗药物监测及新药开发中发挥越来越重要的作用。但目前国内该领域的研究尚不多,有待大力发展。另外,M&S涉及的数学知识较多,造成研究者阅读文献和实际应用的困难。本系列文章简要介绍M&S的一些基本概念及重要原理,供读者参考。本部分着重说明了数学模型的定义、特点、分类,以及建模解决实际问题的基本思路。
文摘数学建模与模拟(modeling and simulation,M&S)是药代动力学(药动学)与药效动力学(药效学)中重要的定量研究方法,在研究药物的处置和作用的机理、治疗药物监测及新药开发中发挥越来越重要的作用。但目前国内该领域的研究尚不多,有待大力发展。另外,M&S涉及的数学知识较多,造成研究者阅读文献和实际应用的困难。本系列文章简要介绍M&S的一些基本概念及重要原理,供读者参考。本部分着重讨论模型开发过程及拟合优度标准的有关问题。
