Design of ileo-colon releasing tablet dosage form by compression coating: effect of carboxymethyl chitosan on budesonide release.

Microbiotically activated ileo-colonic delivery of budesonide from compression coated tablets with considerably reduced carboxymethyl chitosan (CMCH) concentration was designed and investigated. CMCH was synthesized from chitosan dissolved in 20%w/v sodium hydroxide (NaOH) with monochloroacetic at 40 ± 5 °C and characterized by proton NMR, FTIR and Degree of Substitution. The microbiotically activated compression coated tablets (MACC-TABs) were prepared by wet granulation and compression coated with Eudragit S100: HPMC K100M in different ratios for enteric protection and ileo-colon selectivity. Dissolution studies without enzymes and in the presence of enzymes such as pepsin at pH 1.2, diastase and pancreatin at pH 6.8, the F1C3 did not show significant changes. Addition of colonic enzymes at the tenth hour resulted in significant increase in release of budesonide. The % Cumulative Drug Release was 98.49 ± 1.42%, due to the enzymatic triggering (produced by the colonic microflora) leading to the lysis of glycosidic bonds. Scanning electron microscopy revealed the pores formed after dissolution was due to the water-soluble nature of CMCH to release budesonide. The evidence during in-vitro dissolution studies confirmed the pH sensitivity along with microbiotic activation of the MACC-TABs tablets to efficiently and reproducibly release budesonide in the ileo-colon site in the presence of the bacterial enzymes. [ABSTRACT FROM AUTHOR]