Main Article Content
The pharmacokinetic study was carried out on levonorgestrel tablets from two different sources (Hugarian-and Thai-made). Both preparations contained 0.75 mg levonorgestrel and had been used for postcoital contraception. Twelve-female subjects were given a single oral dose of 0.75 mg tablets in a crossover design. Plasma levonorgestrel concentration were determined via radio-immunoassay technique. The pharmacokinetic analysis of the levonorgestrel data was performed on the basis of a two-compartment open model using a M.K. model program. Absorption and bioavailability of the Hungarian-made tablets were slightly higher as evidenced by higher serum concentrations of levonorgestrel in the first 2 hours. Thai-made tablets showed a slightly greater area under the concentration-time curve (AUC) during the first 24 hours. The volume distribution (Vd), the clearance (CL) and elimination half-life (T1/2) of both preparations were closely. Comparing the pharmacokinetic parameters (Cmax, Tmax, T1/2, CL, Vd, AUC) by using t-test were not statistically significant difference. It implied that both preparations (Hungarian-and Thai-made) were bioequivalent with each other.
Upon acceptance of an article, the Pharmacological and Therapeutic Society of Thailand will have exclusive right to publish and distribute the article in all forms and media and grant rights to others. Authors have rights to use and share their own published articles.