D. Vijay Kumar*, CH. Praveen Kumar, CH. Pradeep kumar, K. Gnanaprakash
Department of Pharmaceutics,
Ratnam Institute of Pharmacy, SPSR Nellore, Andhra Pradesh, India-524346
The aim of the present study was to develop colon targeted drug delivery system for Levamisole using Eudragit L-100 and cellulose acetate phthalate (CAP). Levamisole is an anthelminthic and immunomodulator belonging to the class of imidazothiazole derivatives. It is a white to pale cream powder, odorless and soluble in water. Levamisole is rapidly absorbed from GIT and its half life is 4.4 to 5.6 hrs which is major limitation for levamisole. Due to its less t1/2,doses of levamisole produced severe reactions in the GIT. Hence matrix formulation containing various proportions of Eudragit L-100 and CAP were prepared by direct compression technique. All the formulations were evaluated for in-process quality control tests and the in-vitro drug release study was undertaken at 37 + 0.50c in 0.1N HCl for 2hrs followed by 7.4 pH phosphate buffer for 3hrs and 6.8 pH phosphate buffer for 19hrs. Results indicated that drug release has been retarded more by using Eudragit L-100 than by using CAP and 1:1 ratios of Eudragit L-100 and CAP. Formulation LM-4 (Eudragit L100 -5 % w/v) seems to quiet promising for colonic drug delivery with only 7.6 % drug release in first 5hrs. After 24 hrs cumulative percent drug release for LM-4 was found to be 98.4%. Drug release kinetics revealed that, drug release from LM-4 follows zero order release with fickian diffusion. Whereas Levamisole formulations did not release drug in stomach and small intestine but delivered drug to the colon resulting in slow absorption of drug and making drug available for local action in the colon.
Key words: Colon specific drug delivery system, CDDS, Esemoprazole, cellulose acetate phthalate, entric coated tablet.