Relative bioavailability study of 20-mg enalapril tablets in healthy male volunteers.

The pharmacokinetic and relative bioavailability studies of 20-mg enalapril tablets, the test product manufactured by Biolab, Thailand compared to the reference product (Merck Sharp & Dohme, USA) was conducted in 14 healthy Thai male volunteers following a single dose, two-period, crossover design. Each subject received 20-mg enalapril tablets of both formulations with a 1-week washout period. Plasma samples collected over a 24-h period after administration were analyzed by LC/MS/MS. Pharmacokinetic parameters were determined by using non-compartmental analysis. Regarding bioequivalence testing, the 90 per cent confidence intervals of Cmax and AUC(0-infinity) ratios (test/reference) of enalapril were 101.8-134.9 per cent and 105.9-121.4 per cent and those of enalaprilat were 104.2-122.3 per cent and 104.5-118.1 per cent. Based on the European bioequivalence guideline, the 90 per cent confidence intervals of Cmax and AUC(0-infinity) ratios of both parent and metabolite forms were within the acceptable ranges of 70-143 per cent and 80-125 per cent, respectively. It was concluded that the test formulation was bioequivalent to the reference formulation and both formulations can be used interchangeably in clinical practice.

Bioequivalence study of ondansetron tablet in healthy Thai male volunteers.

OBJECTIVES: To assess the average bioequivalence of two formulations of 8-mg ondansetron tablets--test product (Unison Laboratories, Thailand) and reference product (Glaxo Wellcome, USA)--in 14 healthy Thai male volunteers. MATERIAL AND METHOD: In a randomized, single dose, fasting, two-period, crossover study design with a 1-week washout period, each subject received an 8-mg ondansetron tablet. Serum samples were collected over a 24-hour period after administration. Subsequently serum concentrations of ondansetron were analyzed by using a validated HPLC-UV method. Pharmacokinetic parameters were determined by using non-compartmental analysis. RESULTS: No significant difference was observed in any of the pharmacokinetic parameters analyzed. The time to reach the maximal concentration (Tmax, hour), the peak concentration (Cmax, ng/ ml) and the area under the concentration-time curve (AUC(0-infinity), ng x h/ml) of ondansetron for reference and test preparations were 2.6 + 1.8 vs 2.2 + 0.6, 49.5 +/- 18.9 vs 48.5 +/- 13.7 and 352.2 +/- 184.7 vs 323.8 +/- 154.5, respectively. The 90 per cent confidence intervals for Test/Reference ratio of Cmax and AUC(0-infinity) were found within the bioequivalence range of 80-125 per cent (90.3-110.0% and 88.4-99.6%, respectively). CONCLUSION: The bioequivalence of these two ondansetron preparations was demonstrated.

Bioequivalence study of enalapril tablets in healthy Thai male volunteers.

The bioequivalence study of 5-mg enalapril tablets, Enaril (Biolab, Thailand) compared to Renitec (Merck Sharp & Dohme, USA) was conducted in 14 healthy Thai male volunteers following a single dose, two-period, crossover design. Each subject received 4 tablets of 5-mg enalapril tablets of both formulations with a 1-week washout period. Plasma samples collected over a 24-hour period after administration were analyzed by LC/MS/MS. Pharmacokinetic parameters were determined by using non-compartmental analysis. Regarding bioequivalence testing, the 90 per cent confidence intervals of Cmax and AUC(0-infinity) ratios (Enaril/Renitec) of enalapril were 86.3-126.1 per cent and 93.0-118.5 per cent and those of enalaprilat were 86.4-124.1 per cent and 90.3-116.8 per cent. Based on the European bioequivalence guideline, the 90 per cent confidence interval of Cmax and AUC(0-infinity) ratios of both parent and metabolite forms were within acceptable ranges of 70-143 per cent and 80-125 per cent, respectively. It was concluded that Enaril 5 mg tablet was bioequivalent to Renitec 5 mg tablet.

Measurement of HDL-cholesterol in serum by a new enzymatic method.

High density lipoprotein (HDL) are responsible for the reverse transport of cholesterol from the peripheral cells to the liver. Here, cholesterol is metabolised. Monitoring of HDL-C in serum is of clinical importance since an inverse correlation exists between serum HDL-C concentrations and the risk of atheroselerotic disease. Elevated HDL-C concentrations are protective against coronary heart disease. In this study, an automated enzymatic method for the direct determination of HDL-C in serum was found to have good precision and accuracy. Reproducibility was determined daily using control precinorm? L in an internal protocol (n=20), within-run CV = 1.3% and between-day CV = 2.013%. The comparison of the HDL-C enzymatic assay with HDL-C precipitating agent was good with a correlation coefficient r = 0.965, Y = 1.981+ 0.959X, n =172. The normal range of HDL-C concentration in serum by this enzymatic method was 36.16 -86.08 mg./dl. Thus, a HDL-C level of over 35 mg/dl., shows the risk is not high and is protective against coronary heart disease.

Measurement of LDL-cholesterol in serum by new enzymatic method.

Low density Lipoprotein (LDL) plays a key role in causing and influencing the progression of atherosclerosis and coronary sclerosis in particular. The LDLs are derived from Very Low Density Lipoproteins (VLDLs). The elimination of LDL from plasma takes place mainly by the liver parenchymal cells via specific LDL receptors. The LDL-cholesterol value is the most powerful clinical predictor among all of the individual parameters with respect to coronary atherosclerosis., Therefore, therapies focusing on lipid reduction primarily target the reduction of LDL-cholesterol which is then expressed in prevention of atherosclerosis. This new enzymatic automated method for direct determinaton of LDL-cholesterol in serum had good precision and accuracy. Reproducibility was determined daily using control precinorm? L in an internal protocol (n = 20), within-run CV = 0.856%, and between-run CV = 2.6%. The comparison of the LDL-C level by enzymatic assayed with the calculated LDL-C using the HDL-C determination by enzymatic assayed and by precipitation, showed a good correlation ( r = 0.989, Y = 0.966X - 7.255, n = 188 and r = 0.977, Y = 0.957X - 7.049, n = 188). The normal range of LDL-C concentration in serum by this enzymatic method was 57.47 - 221.39 mg./dl. Thus,a normal level of LDL-C should be < 200 mg./dl. for good warning. A level > 200 mg/dl warns the doctors that the patient has a high risk of coronary atherosclerosis.