Bioavailability and stability of erythromycin delayed release tablets.
BACKGROUND
Erythromycin is available as the free base, ethylsuccinate, estolate, stearate, gluceptate, and lactobionate derivatives. When given orally erythromycin and its derivatives except the estolate are inactivated to some extent by the gastric acid and poor absorption may result.


OBJECTIVE
To establish whether delayed release erythromycin tablets meet the bioequivalent requirement for the market.


METHODS
Sectrophotometric 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 bioavailability 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 2.3 hr, Tmax.4.5 hr, and Cmax 2.123 g/ml Ka 0.38048 hr(-1) T (1/2) 1.8 hr, V*C/F 49.721 AUC 12.9155. The relative bioavailability of erythromycin delayed release tablet to erythromycin capsules was 105.31%


CONCLUSIONS
The content, appearance, and dissolution bioavailability 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.
Ogwal
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S
Department of pharmacy, Faculty of Medicine, Makerere University, P. O. Box 7072, Kampala Uganda. sidneyogwal@hotmail.com
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D000284:Administration, Oral; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics*; D001682:Biological Availability; D003692:Delayed-Action Preparations; D004917:Erythromycin / Q000493:pharmacokinetics*; D005765:Gastrointestinal Agents / Q000493:pharmacokinetics*; D006801:Humans; D066298:In Vitro Techniques; D013270:Stomach / Q000187:drug effects; D013608:Tablets, Enteric-Coated
D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D005765:Gastrointestinal Agents; D013608:Tablets, Enteric-Coated; D004917:Erythromycin