IN-VIVO PERFORMANCE OF A MULTIPARTICULATE MATRIX, CONTROLLED-RELEASE THEOPHYLLINE PREPARATION

An experimental multiparticulate matrix sustained-release theophylline preparation was evaluated in vivo, in comparison with Neulin-SR(R). T welve healthy volunteers participated in the study, conducted accordin g to a randomized, two-way crossover study design. The preparations we re compared using the pharmacokinetic parameters, peak serum concentra tion (C-max, total area under the serum concentration-rime curve (AUC( 0-infinity)), time to reach peak serum concentration (T-max), and time for 50% dose absorption in vivo (T-50%). A statistically significant difference was observed in the T-max and T-50% values (p < 0.05) but n ot in the logarithmic transformed values of C-max and AUC(0-infinity). These findings indicate that the two preparation are comparable in th e extent but differ in the rate of absorption, with the experimental p reparation being more sustained. In addition, the elimination rate con stant (K-e), elimination half-life (t(1/2)), and apparent volume of di stribution (V-d) of the drug were calculated. There was no statistical ly significant difference between the K-e, t(1/2), and V-d values obta ined from the data of the two preparations. Moreover, the values obtai ned are comparable to those reported in the literature. A satisfactory correlation was also obtained between the mean in vivo absorption and mean in vitro dissolution data (p < 0.001) for both preparations.