Design and Characterization of Hydrogel based Mesalamine Microbeads for Colon Targeted Drug Delivery System

Tadakapally Ramchandar^1*, Jimidi Bhaskar², Kanakam vijaya Bhaskar³, V.L. Narasaiah^4
1Department of Pharmaceutics, Mother Teresa college of Pharmacy, Ghatkesar, Hyderabad, Telangana.
²Department of Pharmaceutics, Avanthi Institute of Pharmaceutical Sciences, Gunthapally, Near Ramoji Film city, Hyderabad, Telangana, India.
³Department of Pharmacognosy, Sahasra Institute of Pharmaceutical Sciences, Warangal, Telangana.
⁴Dept. of Pharmaceutics, Dr Samuel George Institute of Pharmaceutical Sciences, Markapur, A.P, India.

A B S T R A C T
Mesalamine (5-ASA) is an anti-inflammatory drug used in treatment of Crohn’s disease and ulcerative-colitis. As Mesalamine is rapidly absorbed from the small intestine and it is necessary to develop a colon-specific delivery system for it. In the long-term management of ulcerative colitis patients, repeat dosing maybe required. Since Mesalamine (5-ASA) is largely absorbed from the upper intestine, selective delivery of drugs into the colon may be regarded as a better method of drug delivery with fewer side effects and a higher efficacy. An objective of the present investigation is to prepare and evaluate Mesalamine microbeads for colon targeting. These microbeads were prepared by emulsion solvent evaporation method using different ratios of Mesalamine, Carbopol (CP) and Guar gum (GG), stirring speed (1000rpm) and emulsifier concentration (0.5% w/v). Carbopol coated Mesalamine microbeads were evaluated for surface morphology, particle size analysis, percentage drug entrapment, percentage yield and in vitro drug release studies. Drug release studies carried out in acidic medium (0.1NHCl) for 2hr and in phosphate buffer pH 7.4 up to 12hrs. In acidic medium, the release rate was much slower; however, the drug was released quickly at phosphate buffer pH 7.4. Microbeads prepared by using drug: polymer: polymer ratio 1:0.75:0.75 stirring speed 1000 rpm, and 0.5% wt/v concentration of glutarldehyde (emulsifier) were selected as an optimized formulation. It is concluded from the present investigation that Mesalamine microbeads are promising controlled release carriers for colon-targeted drug delivery.
Keywords: Mesalamine, Carbopol, Guar gum, colon targeted, microbeads.