Oral drug delivery using a polymeric nanocarrier: chitosan nanoparticles in the delivery of rifampicin

Oral delivery of drugs is the most common method of drug administration. However, the poor bioavailability of drugs in the systemic circulation makes achieving therapeutic levels via the gastrointestinal (GI) tract challenging. Polymeric nanoparticle drug carriers can shield drugs from degradation and deliver them in the upper intestinal region of the GI tract. In this regard, we have developed a nanocarrier from a naturally occurring polymer, chitosan, to investigate its efficacy in a pH-responsive environment to be used as a potential drug delivery vehicle. We have monitored the encapsulation of an anti-tuberculosis drug, rifampicin (RF), to investigate its pH-responsive delivery activity. Although RF is poorly soluble in aqueous media, it is a clinically effective drug due to its ability to inhibit bacterial RNA polymerase. The inescapable necessity and poor solubility automatically necessitate an alternative drug delivery/carrier system. The chitosan nanoparticle system ensures a burst delivery efficiency of 75% of rifampicin at a simulated intestinal pH over a period of 24 hours. Our studies have successfully established the chitosan nanocarrier as a promising oral drug delivery vehicle.