BIOAVAILABILITY OF TETRACYCLINE, TETRACYCLINE HYDROCHLORIDE AND COMPLEXES

Document Type : Original Article

Authors

Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt

Abstract

The irregular and incomplete absorption of tetracycline from the GIT, directs the attention to use the organic complexes of this compound in therapy. Tetracycline complexes with urea, gentisic and pyrocatechuic acids were prepared and investigated in comparison with both tetracycline base and its hydrochloride salt. No correlation was found between the in-vitro results of lipophilicity of tetracycline base and its complexes and their availability. However, a correlation existed between the in-vitro T50% dissolution of tetracycline base, tetracycline hydrochloride and its complexes in distilled water adjusted to pH 2 and their cumulative urinary excretion by human volunteers. The impaired absorption of tetracycline when administered with milk was found to be greatly reduced in case of tetracycline hydrochloride, while the absorption of tetracycline-pyrocatechuic and gentisic acids complexes were the least affected.