Abstract

FORMULATION OF EUDRAGIT S 100 COATED SODIUM ALGINATE MICROSPHERES OF AZATHIOPRINE FOR COLON TARGETING

Abhishek S. B.*, Parthiban S., Senthil Kumar G. P., Tamizh Mani T.

ABSTRACT

The purpose of this investigation was to prepare and evaluate colon specific microspheres of Azathioprine for the treatment of bowel syndrome. Sodium alginate microspheres were prepared by iontropic gelation method using different ratios of Azathioprine and sodium alginate (1:3, 1:4, 1:5). Eudragit S 100-coating of Azathioprine sodium alginate microspheres was performed by coacervation phase separation technique. The microspheres were characterized by shape, particle size, size distribution, drug content, entrapment efficiency, in-vitro drug release studies and stability studies. The outer surfaces of the core and coated microspheres, which were spherical in shape, were rough and smooth, respectively. FTIR study confirmed the compatibility of drug and polymer in physical mixture and coated formulation. The size of the core microspheres ranged from 300-1200μm, and the size of the coated microspheres ranged from 500-1500μm. The core microspheres sustained the release 80 % of drug release at about 12 hrs at pH 7.4 dissolution medium. The release studies of coated microspheres were performed in a pH progression medium mimicking the condition of GIT. The results revealed the absence of drug release for the 2 hrs in pH 1.2 followed by 2-4 hrs (2 hrs) and 4-6 hrs (2hrs) in pH 5.5 and 6.8 respectively, however, the drug was released quickly at pH 7.4 and their release was sustained over a period of 6 – 20 hrs (14 hrs). The thickness of coating influences the release pattern due to more time to dissolve at pH 7.4 It is concluded from the present investigation that Eudragit-coated sodium alginate microspheres are promising controlled release carriers for colon targeted delivery of Azathioprine.

Keywords: Azathioprine, Colon specific, Microspheres, Sodium alginate, Eudragit S-100, Multiparticulate system.