Design and evaluation of bilayer floating tablets of cefuroxime axetil for bimodal release

Study aims to design a gastroretentive delivery system for bimodal release of cefuroxime axetil (CA). CA has site-specific absorption from upper gastrointestinal tract and in intestine it undergoes hydrolysis to cefuroxime having poor absorption. Unabsorbed drug causes high concentration of antibiotic entering colon. and contributes to the side effects like colitis. Therefore, a gastro-retentive dosage form is required to ensure controlled drug delivery within drug-absorbable regions. Bilayer tablet, each layer containing half the dose of drug was formulated with one immediate release layer (IRL) and another floating matrix layer (FML). The FML showed good floating properties with buoyancy lag time of 12-35 min and floating time of 8-24 h. Thus, bimodal drug release comprising of immediate release for quick onset of action followed by controlled release minimizing the concentration of unabsorbed drug entering colon was achieved. No change in amorphous nature of drug during processing was observed, which was confirmed by differential scanning colorimeter and X-ray diffractometer. The gamma-sintigraphy confirmed the gastric residence of tablets in human volunteers.