Shahul Hussain Shaik*1, Dr. Shailesh Sharma2
1Research Scholar, NIMS Institute of Pharmacy, NIMS University, Shobhanagar, Jaipur, Rajasthan
2Associate Professor, NIMS Institute of Pharmacy, NIMS University, Shobhanagar, Jaipur, Rajasthan
A B S T R A C T
A colonic drug delivery system is expected to protect the drug during the transit time in the GIT and to allow its release only in the colon. Colonic drug delivery is also useful for systemic absorption of drugs, especially peptides and proteins, because of less hostile environment prevailing in the colon compared to stomach and small intestine. The purpose of the present study is to investigate the colon specificity of polysaccharides in synthesis of prodrug and to formulate. The polysaccharides as polymer are mainly used to carry the drug moiety to the colon both in prodrug concept and formulation. Prodrug, Ibuprofen – β-cyclodextrin have been synthesized and investigated and was found to be colon specific, though, the yield was found to be very poor. From the in-vivo study it was also found to be very effective. As far as the formulations with polysaccharides are concerned, a novel polymer khaya gum was investigated for its colon specificity and compared with a well-established polysaccharide polymer guar gum. It was found that the polysaccharides are very effective for targeting the drug to colon provided they are further coated with enteric polymer. Further, the present investigation also revealed that the effect of solubility of the drugs on the colon specificity of the polysaccharides. The investigation revealed that the prodrugs of drug molecules with polysaccharides are better colon specific compared to the formulations prepared with the polysaccharides. This is because the hydrophilicity nature of the polysaccharides releases the drug in the stomach to some extent especially weakly basic drugs. However, they are very effective when coated further with enteric polymer. Prodrugs with polysaccharides, though soluble in the aqueous solutions, there is a need of enzyme system to break the covalent bond formed between the drug molecule and the polysaccharide. Hence, irrespective of the nature of the drug, prodrug approach is better to target the drugs to colon compared to the formulations with polysaccharides.
Keywords: Prodrug, polysaccharide, khaya gum, guar gum, colon specificity