Cryogels are gel matrices that have interconnected macropores and are formed in freezing-thawing systems. These interconnected macropores give elasticity to cryogels. Transdermal controlled-release systems can be used...Cryogels are gel matrices that have interconnected macropores and are formed in freezing-thawing systems. These interconnected macropores give elasticity to cryogels. Transdermal controlled-release systems can be used to deliver drugs with short biological half-life and can maintain plasma levels of very potent drugs within a narrow therapeutic range for prolonged periods. In this study, cryogels have been used in a different area--transdermal controlled-release system, to obtain controlled drug release medium. For this purpose, naproxen sodium has been selected as a model drug. Naproxen, a propionic acid derivative, is a NSAID （nonsteroidal anti-inflammatory drug）. For controlled releasing of naproxen sodium, cryogels that have naproxen sodium in macropores have been prepared in sheet form for local application. Acrylamide based cryogel bands have been synthesized by flee radical cryogelation process. These cryogel bands have different pore size and includes naproxen sodium in their pores. This cryogel material has been characterized by swelling tests and SEM. Then, releasing ofnaproxen sodium from cryogels has been investigated at two different pH values, 7.4 and 5.5. According to experimental data, it has seen that these cryogel matrices that including naproxen sodium in macropores could be used in controlled drug releasing systems as bandages or other transdermal controlled releasing agents at room temperature展开更多
The pharmacokinetics of a sustained- release formulation and an enteric- coated tablet of diclofenac sodium were studied on 8 healthy male volunteers in an open,randomized crossover study.Drug level in serum was assay...The pharmacokinetics of a sustained- release formulation and an enteric- coated tablet of diclofenac sodium were studied on 8 healthy male volunteers in an open,randomized crossover study.Drug level in serum was assayed by HPLC method.The changes in serum concentration were conformed to a l-compartment open model.The t_1/2 (Ke)averaged 2.15±0.17 and ll.60 ± l.95 h,and the areas under the drug concentration curves were 5.87 ± 0.67 and 5.55 ± 0.57μgh/ml for enteric-coated and sustained-release tablet of diclofenac sodium,respectively. The mean relative bioavailability of sustained-release tablet was 0.95 to that of enteric-coated tablet.展开更多
A new rapid, simple and reproducible UV spectrophotometric method was developed and validated for the estimation of Naproxen Sodium (NpSd) in bulk and pharmaceutical formulation. The quantification of NpSd was done at...A new rapid, simple and reproducible UV spectrophotometric method was developed and validated for the estimation of Naproxen Sodium (NpSd) in bulk and pharmaceutical formulation. The quantification of NpSd was done at 230 nm in methanol and in buffer of pH 6.8 and 9. Beer’s law was obeyed in the concentration range of 4 - 36 (r2 = 0.999) in methanol and 5 - 25 μgmL﹣1 in buffer of pH 6.8 and 9 (r2 = 0.988 and 0.997) respectively. The apparent molar absorptivity values were also calculated in all mediums. All parameters according to ICH guideline were tested and validated. The detection and quantitation limits were found to be 0.054, 0.083, 0.073 and 0.181, 0.251, 0.211 μgmL﹣1 respectively. These methods were applied directly to the analysis of the pharmaceutical tablet preparations (Anex? tablet 250 mg). The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation 3%), while being simple, cheap and less time consuming and hence can be suitably applied for the estimation of NpSd in dosage forms and dissolution studies.展开更多
Background Mycophenolic acid （MPA） as an anti-proliferative immune-suppressive agent is used in the majority of immunosuppressive regimens in solid organ transplantation. This study aimed to investigate the pharmaco...Background Mycophenolic acid （MPA） as an anti-proliferative immune-suppressive agent is used in the majority of immunosuppressive regimens in solid organ transplantation. This study aimed to investigate the pharmacokinetic （PK） characteristics of enteric-coated mycophenolate sodium （EC-MPS） and area under the curve （AUC） from 0 to 12 hours with limited sampling strategies （LSSs） in Chinese renal transplant recipients. Methods This study was conducted in 10 Chinese renal transplant patients receiving living donor and treated with EC-MPS, cyclosporine, and corticosteroids. MPA concentrations were measured by enzyme multiplied immunoassay technique （EMIT）. Whole 12-hour PK profiles were obtained on Day 4 after operation. LSSs with jackknife technique, multiple stepwise regression analysis, and Bland-Altman analysis were developed to estimate MPAAUC. Results The mean maximum plasma concentration, the mean time for it to reach peak （Tmax）, and the mean MPA AUC were （11.38±2.49） mg/L, （4.85±3.32） hours, and （63.19±13.54） mg.h.L1, respectively. Among the 10 profiles, MPA AUC of four patients was significantly higher than that of the other six patients, and the corresponding Tmax was significantly longer than that of the other six patients. No patient exhibited a second peak caused by enterohepatic recirculation. The best models were as follows： 27.46＋0.94C3＋3.24C8＋2.81C10 （f2=0.972）, which was used to predict AUC of fast metabolizer with a mean prediction error （MPE） of -0.21% and a mean absolute prediction error （MAE） of 2.59%; 36.65＋3.08Ce＋5.30C10-4.04C12 （r2=0.992）, which was used to predict AUC of slow metabolizer with a MPE of 0.58% and a MAE of 1.95%. Conclusions The PKs of EC-MPS had a high variability among Chinese renal transplant recipients. The preliminary PK data indicated the existence of slow and fast metabolizer. These findings may be associated with the enterohepatic rec.irculation.展开更多
The aim of the research was to investigate the pharmacokinetics(PK) of enteric-coated mycophenolate sodium(EC-MPS) by quantification of the active metabolite of mycophenolic acid(MPA)after multiple escalating oral dos...The aim of the research was to investigate the pharmacokinetics(PK) of enteric-coated mycophenolate sodium(EC-MPS) by quantification of the active metabolite of mycophenolic acid(MPA)after multiple escalating oral doses in Han kidney transplant recipients. A total of 28 Han postoperative kidney transplant recipients were given a multiple-dose of 540, 720 or 900 mg of EC-MPS two times a day in combination with tacrolimus for 6 days. Blood specimens were collected at each time point from0 to 12 h after EC-MPS administration. MPA plasma concentrations were measured by UPLC–UV. The relationship between the EC-MPS dose and its PK parameters was assessed. In the range from 540 to900 mg, C_(max) and AUC_(0–12h) did not increase with dose escalation. The AUC_(0–12h), C_(max), C_0 and T_(max) for the 540 720 and 900 mg doses were not significantly different, respectively(P 40.05). AUC_0–12 h and C_(max) were increased less than proportionally with increasing EC-MPS dose levels. Inter-individual variability in AUC_(0–12h), C_(max) and C_0 were considerable. Nonlinear PK relationships were found from the doses of 540–900 mg of EC-MPS.展开更多
文摘Cryogels are gel matrices that have interconnected macropores and are formed in freezing-thawing systems. These interconnected macropores give elasticity to cryogels. Transdermal controlled-release systems can be used to deliver drugs with short biological half-life and can maintain plasma levels of very potent drugs within a narrow therapeutic range for prolonged periods. In this study, cryogels have been used in a different area--transdermal controlled-release system, to obtain controlled drug release medium. For this purpose, naproxen sodium has been selected as a model drug. Naproxen, a propionic acid derivative, is a NSAID （nonsteroidal anti-inflammatory drug）. For controlled releasing of naproxen sodium, cryogels that have naproxen sodium in macropores have been prepared in sheet form for local application. Acrylamide based cryogel bands have been synthesized by flee radical cryogelation process. These cryogel bands have different pore size and includes naproxen sodium in their pores. This cryogel material has been characterized by swelling tests and SEM. Then, releasing ofnaproxen sodium from cryogels has been investigated at two different pH values, 7.4 and 5.5. According to experimental data, it has seen that these cryogel matrices that including naproxen sodium in macropores could be used in controlled drug releasing systems as bandages or other transdermal controlled releasing agents at room temperature
文摘The pharmacokinetics of a sustained- release formulation and an enteric- coated tablet of diclofenac sodium were studied on 8 healthy male volunteers in an open,randomized crossover study.Drug level in serum was assayed by HPLC method.The changes in serum concentration were conformed to a l-compartment open model.The t_1/2 (Ke)averaged 2.15±0.17 and ll.60 ± l.95 h,and the areas under the drug concentration curves were 5.87 ± 0.67 and 5.55 ± 0.57μgh/ml for enteric-coated and sustained-release tablet of diclofenac sodium,respectively. The mean relative bioavailability of sustained-release tablet was 0.95 to that of enteric-coated tablet.
文摘A new rapid, simple and reproducible UV spectrophotometric method was developed and validated for the estimation of Naproxen Sodium (NpSd) in bulk and pharmaceutical formulation. The quantification of NpSd was done at 230 nm in methanol and in buffer of pH 6.8 and 9. Beer’s law was obeyed in the concentration range of 4 - 36 (r2 = 0.999) in methanol and 5 - 25 μgmL﹣1 in buffer of pH 6.8 and 9 (r2 = 0.988 and 0.997) respectively. The apparent molar absorptivity values were also calculated in all mediums. All parameters according to ICH guideline were tested and validated. The detection and quantitation limits were found to be 0.054, 0.083, 0.073 and 0.181, 0.251, 0.211 μgmL﹣1 respectively. These methods were applied directly to the analysis of the pharmaceutical tablet preparations (Anex? tablet 250 mg). The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation 3%), while being simple, cheap and less time consuming and hence can be suitably applied for the estimation of NpSd in dosage forms and dissolution studies.
文摘Background Mycophenolic acid （MPA） as an anti-proliferative immune-suppressive agent is used in the majority of immunosuppressive regimens in solid organ transplantation. This study aimed to investigate the pharmacokinetic （PK） characteristics of enteric-coated mycophenolate sodium （EC-MPS） and area under the curve （AUC） from 0 to 12 hours with limited sampling strategies （LSSs） in Chinese renal transplant recipients. Methods This study was conducted in 10 Chinese renal transplant patients receiving living donor and treated with EC-MPS, cyclosporine, and corticosteroids. MPA concentrations were measured by enzyme multiplied immunoassay technique （EMIT）. Whole 12-hour PK profiles were obtained on Day 4 after operation. LSSs with jackknife technique, multiple stepwise regression analysis, and Bland-Altman analysis were developed to estimate MPAAUC. Results The mean maximum plasma concentration, the mean time for it to reach peak （Tmax）, and the mean MPA AUC were （11.38±2.49） mg/L, （4.85±3.32） hours, and （63.19±13.54） mg.h.L1, respectively. Among the 10 profiles, MPA AUC of four patients was significantly higher than that of the other six patients, and the corresponding Tmax was significantly longer than that of the other six patients. No patient exhibited a second peak caused by enterohepatic recirculation. The best models were as follows： 27.46＋0.94C3＋3.24C8＋2.81C10 （f2=0.972）, which was used to predict AUC of fast metabolizer with a mean prediction error （MPE） of -0.21% and a mean absolute prediction error （MAE） of 2.59%; 36.65＋3.08Ce＋5.30C10-4.04C12 （r2=0.992）, which was used to predict AUC of slow metabolizer with a MPE of 0.58% and a MAE of 1.95%. Conclusions The PKs of EC-MPS had a high variability among Chinese renal transplant recipients. The preliminary PK data indicated the existence of slow and fast metabolizer. These findings may be associated with the enterohepatic rec.irculation.
基金supported by the youth fund of The First Affiliated Hospital of Zhengzhou University
文摘The aim of the research was to investigate the pharmacokinetics(PK) of enteric-coated mycophenolate sodium(EC-MPS) by quantification of the active metabolite of mycophenolic acid(MPA)after multiple escalating oral doses in Han kidney transplant recipients. A total of 28 Han postoperative kidney transplant recipients were given a multiple-dose of 540, 720 or 900 mg of EC-MPS two times a day in combination with tacrolimus for 6 days. Blood specimens were collected at each time point from0 to 12 h after EC-MPS administration. MPA plasma concentrations were measured by UPLC–UV. The relationship between the EC-MPS dose and its PK parameters was assessed. In the range from 540 to900 mg, C_(max) and AUC_(0–12h) did not increase with dose escalation. The AUC_(0–12h), C_(max), C_0 and T_(max) for the 540 720 and 900 mg doses were not significantly different, respectively(P 40.05). AUC_0–12 h and C_(max) were increased less than proportionally with increasing EC-MPS dose levels. Inter-individual variability in AUC_(0–12h), C_(max) and C_0 were considerable. Nonlinear PK relationships were found from the doses of 540–900 mg of EC-MPS.
