EFFECT OF GUAR GUM AND XANTHAN GUM COMPRESSION COATING ON RELEASE STUDIES OF METRONIDAZOLE IN HUMAN FECAL MEDIA FOR COLON TARGETED DRUG DELIVERY SYSTEMS

摘要

Objective: Compression coating with polysaccharides such as guar gum (GG) and xanthan gum (XG) mixture has been pioneer to be useful for microflora activated colon drug delivery systems. Method: In the present investigation bacteria triggered colon-targeted delivery of metronidazole (MTZ) was developed by compression coating with GG and XG in different coat weights. Rapidly disintegrating core tablets containing 100 mg of MTZ were prepared and compression coated with 150 mg, 250 mg and 350 mg of granules containing a mixture of GG and XG. Results: Drug release was highly retarded with 350 mg of coat weight, After 24 h of dissolution in human fecal media the cumulative percentage of drug release form the 350 mg compression coated tablets was found to be around 21.0±1.65%. As a result, the coat weight was further reduced to 250 mg. It was perceived that reduction in coat weight to 250 mg did not affect the initial drug release rate in simulated upper gastrointestinal tract (GIT) conditions, but at the end of the 24 h of dissolution the amount of drug release was increased to 84.8±1.22% in simulated human fecal media. On the other hand, 150 mg compression coated tablets showed 28.56±1.89% drug release in upper GIT, which indicates uncontrolled drug release within 5 h of the dissolution study. Conclusion: As a consequence, results of the present investigation shows that compression coated MTZ tablets with 250 mg of guar and xanthan gum coat is most likely to promise in exploiting the MTZ release in colon to treat amoebiasis and other local colonic diseases.