Release Characteristics and Bioavailability of Norfloxacin from Suppository Bases

Abstract

The in vitro release of norfloxacin (a new broad spectrum antimicrobial agent whose pharmacokinetics are characterised by varied gastrointestinal absorption and irregular plasma level) from different suppository bases was studied in order to obtain suitable formulation with good release and satisfactory drug concentrations in plasma. The bioavailability of suppositories containing 200 mg drug made from the bases that showed the best in vitro release was investigated. The release rate was in the order of PEG 400, 1540, 4000 mixture in ratio of 20: 33: 47 respectively > Witepsol H1S > Witepsol W 35 > Witepsol E 75. Addition of Tween 20, Tween 80 and Myrj 45 to the Witepsol members greatly increased the release rate especially at surfactant concentration of 5 × 10 mol.g. of the drug.