Design and formulation of Paclitaxel colon drug delivery system by using chitosan/cellulose acetate phthalate two layer coating

Abstract

Introduction: Colorectal cancer medicine nowadays consists mostly of injection form which can have severe adverse effects. Therefore, attempts on designing and formulating the oral form of the drug have been made for local treatment of cancer and to reduce negative side effects. Aim: The goal of the present study is to design a colon drug delivery system consisting of two-layer enteric and colonic coating to prevent drug release in GI tract. Since Paclitaxel is rapidly released in colon and is not absorbed in GI tract, it will directly affect the colon epithelial cells, significantly reducing the adverse side effects of systemic absorption of drug. Methods: The central core was made using direct compression and it was coated in two stages using dip coating method. Formulation of colonic coating consists of chitosan and plasticizer in acetic acid solution using tri-poly phosphate solution as partial crosslink. In the second coating stage, acetate phthalate cellulose was used as colonic coating. Results: Test results showed reliable resistance of enteric coating in SGF medium and biodegradable coating in SIF medium. Dissolution tests showed no drug release in these media. Biodegradable coating tests showed that the coating was degraded in biological medium via the tests in rats’ colon and cecum for a variety of time durations. Discusion: Statistical analysis of results showed no significant difference between drug release in colon and cecum. However, a correlation between elapsed time and drug release was observed in a way that in the biological medium, more drug was released with passing of time.