抄録
Dissolution profiles of newly marketed sustained-release preparations of Flemphyline® tablets containing 100 and 200mg theophylline were compared with those of Theo-Dur® tablets under various media and conditions. The dissolution patterns of theophylline generated by the new preparations examined in the media at pH 1.2 and 6.8 were found to be different. Differences were also apparent in the dissolution rates seen among the preparations.
The bioavailabilities following oral administration of Flemphyline tablets was studied in five volunteers by measuring the salivary concentrations and comparing them with those derived from the Theo-Dur tablets. The pharmacokinetic parameters, area under the salivary concentration-time curve up to 24h, and maximum salivary concentration for Flemphyline (100mg) and Theo-Dur were significantly larger compared to Flemphyline (200mg), but there was no difference in the times to maximum salivary concentration among them. These data suggest that each preparation examined in this study is not bioequivalent in the extent of bioavailability.
