抄録
The pharmacokinetic information provided in the package insert of the original pravastatin sodium product and the package inserts of 22 pravastatin sodium generics was examined. Pharmacokinetic parameters had been determined following the oral administration of 10 mg of pravastatin sodium. Package inserts were examined to see if all parameters were given or not and the ratios between the individual pharmacokinetic parameters of the original product (Op) and those of the generic products (Gp) were calculated using the formula PPr=Gp/Op (PPr= pharmacokinetic parameter ratio).
While the package insert of the original product gave values for all of the pharmacokinetic parameters, i.e., Cmax, Tmax, T1/2, and AUC, the package inserts of only 10 of the 22 generic products had values for all four parameters. The PPrs of the generic products were 2.63 ± 0.61, 1.03 3.61 (mean ± S.D., min-max) for Cmax, 0.55 ± 0.09, 0.45-0.80 for Tmax, 1.98±0.78, 0.89-3.92 for T1/2, and 2.95±1.10, 1.25-5.23 for AUC.
Though these results show that the generic products are definitely bioequivalent to the original product, many of them fall outside the acceptability limits (0.8-1.25) for bioequivalence when only the information in their package inserts is compared. Therefore, the package inserts of generic products should specify the name and manufacturer of the reference product used in the bioequivalence studies and also give the pharmacokinetic parameters determined for it. This information will make the package inserts of generic products more useful.
