Co-processing of Chitosan-Kaolin as a Novel Pharmaceutical tablet excipient

Abstract

Multifunctional excipients are gaining interest in tablet production especially the application for direct compression. Chitosan is not the common excipient for direct compression due to poor flowability and inadequate compressibility. Co-processing of chitosan and kaolin is challenge method to overcome these limitations of individual excipients. The purpose of the present study was to develop co-processed chitosankaolin by spray drying technique (rotary atomizer spray dryer) and to characterize the excipient properties. Preliminary study indicated that process parameters of spray drying could not significantly optimize the physicomechanical properties of coprocessed chitosan-kaolin. Meanwhile feed formulation containing chitosan of 70-90%, the developed co-processed excipient has better flow character comparison to the feed composed of 60% chitosan, but the compression of co-processed chitosan-kaolin presented a low tablet hardness. Formation of chitosan nanoparticles is the major factor for desirable tablet hardness. Type of kaolin is also another importance factor which coprocessed chitosan-Ranong kaolin granted the maximum strength. The successful development of co-processed chitosan-kaolin as novel tablet excipient was obtained from feed formulation composed of chitosan and Ranong kaolin paste of 55:45 (C55K45) and the optimum chitosan/tripolyphosphate ratio of 20:1. Co-processing altered the physical properties of co-processed C55K45 in such a way that it enhanced the flowability and tableting performance compare to physical mixture of chitosan and kaolin. Optimum tablet formulation consisted of acetaminophen 80 mg and coprocessed C55K45 320 mg which produced by direct compression. Various physicochemical parameters evaluation of this tablet formulation showed satisfactory results as seen from content uniformity of drug (97.17±1.71 %), disintegration time (1.96±0.67 min), hardness (15.92±1.98 kg), friability (0.22 %) and drug dissolution (>85 %). The results of short term stability study indicated that tablets were stable for the period of six months at 40 oC and 75% RH. These results suggested that coprocessed C55K45 can enhance tablet performances of low compressible drug and even as a multifunctional tablet excipient.