Biovailability and stability of erythromycin delayed release tablets

Sydney Ogwal* and Xide T .U
Department of pharmacy , Faculty of Medicine, Makerere University P . O. Box 7072 Kampala Uganda
Department of Biopharmaceutics, Faculty of Pharmacy , China Pharmaceutical University , 24 Tong jia Xiang, 210009,Nanjing P . R. of china.

ABSTRACT
Background Erythromycin is available as the free base, ethylsuccinate, estolate, stearate, gluceptate, and lactobionate derivatives. When given orallyerythromycin and its derivatives except the estolate are inactivated to some extent by the gastric acid and poor absorption may result.

Objectives
To establish whether delayed release erythromycin tablets meet the bioequivalent requirement for the market
Methods Spectrophotometric analysis was used to determine the dissolution percentage of the tablets in vitro. High performance liquid chromatography and IBM/XT microcomputer was used to determine the biovailability and pharmacokinetic parameters in vivo.

Results
Dissolution percentage in thirty minutes reached 28.9% and in sixty minutes erythromycin was completely released. The parameters of the delayed release tablets were Tlag 2.3hr,Tmax.4.5hr, and Cmax 2.123g/ml Ka 0.38048hr
-1T ½ 1.8 hr, V*C/F 49.721 AUC 12.9155.The relative biovailability of erythromycin delayed release tablet to erythromycin capsules was 105.31%

Conclusion
The content, appearance, and dissolution biovailability of delayed release erythromycin tablets conforms to the United States pharmacopoeia standards. The tablets should be stored in a cool and dry place in airtight containers and the shelf life is temporarily assigned two years