Pharmacological Efficacy of Insulin-Loaded Granules Made Up of Various Grades of Hydroxypropyl Methylcellulose in Normal Rats

The mucoadhesive polymers, if not targeted to colon may increase co-adherence of some drugs’ fate to normal physiology through small intestine, which is most usual site for drugs absorption. The oral delivery of insulin to colon has been proposed to be a reason for promoting cancers as it by-passes liver, a major site of action of insulin. This also increases insulin’s liability to be picked up by various precancerous and cancerous cells having abundance (~10 times more as compared to normal cells) of insulin receptors or insulin-like growth factor receptors [1,2]. In normal physiology, insulin is secreted in small intestine, which enters into portal circulation and acts upon liver for controlling glucose metabolism. Any remaining fraction from liver thereafter enters into systemic circulation [3]. Therefore, if insulin is made to get absorbed from small intestine instead of targeting to colon, it may follow normal route of absorption and can act as per its normal physiology.