Investigation of naproxen compression coated tablets using polysaccharides as carriers for oral based site specific delivery to colon

Colonic drug delivery is naturally of value for the topical treatment of diseases associated with the colon such as Chron’s diseases, ulcerative colitis, colorectal cancer, amoebiasis, but also for its potential for the delivery of proteins and therapeutic peptides. Although oral delivery has become a widely accepted route of administration of therapeutic drugs, the gastrointestinal tract presents several formidable barriers to drug delivery. An attempt has been made to develop compressioncoated matrix tablets of naproxen using polysaccharides (Locust Bean Gum- LBG and Chitosan-CS) as coating materials for oral based colonic targeting. Core tablet containing 100 mg of naproxen were compression coated with LBG and CS. The FTIR studies indicated that the drug is intact in the formulations and no possibility of interaction between the naproxen and other formulation excipients was observed. It was found that the compression-coated tablets released the drug in the physiological environment of stomach and small intestine in simulated colonic fluid at a specific rate. In vitro studies conducted with and without rat caecal contents for the various formulations and revealed that dug delivery based on the microbially triggered enzyme activated system and followed with sustained release pattern for 48 h.