Abstract

Background and Objective: Amoebiasis, also known amoebic dysentery, is an infection caused by amoebas of the Entamoeba group. Symptoms may include abdominal pain, diarrhoea, or bloody diarrhoea. Complications can include inflammation of the colon with tissue death or perforation, which may result in peritonitis. People affected may develop anemia due to loss of blood. The purpose of present study was to develop Eudragit S100 coated colon targeted sustained release formulations of alginate-pectin and alginate-HPMC microbeads containing Norfloxacin (NF) and Tinidazole (TZ) for the treatment of amoebiasis.

Methods: The formulations were prepared by ionotropic gelation method. Simultaneous estimations of Norfloxacin and Tinidazole were carried out spectrophotometrically at selected wavelengths of 273 and 310 nm. Optimized core beads of alginate-pectin were enteric coated with Eudragit S100. Formulations were evaluated for surface phenomenon, shape of beads, entrapment efficiency and in vitro drug release.

Results: The average size of optimized alginate-pectin microbeads was found to be 881±0.05μm with an entrapment efficiency of 78.50±0.28% (NF) and 86.50±0.32% (TZ). The drug release was 71.16±0.45% (NF) and 80.63±0.56% (TZ) after 8 hr in phosphate buffer pH 6.8. Alginate- HPMC beads were of 902±0.02μm size with entrapment efficiency of 70.47±0.65% (NF) and 69.51±0.09% (TZ). The drug release was 66.95±0.55% (NF) and 73.37±0.43% (TZ) after 8 hr in phosphate buffer of pH 6.8. Enteric coating (10% weight gain) with Eudragit S100 of optimized alginate-pectin microbeads showed 73.15±0.54% (NF) and 81.59±0.56% (TZ) drug release in 12hr. The determined value of regression coefficients for zero order, first order and Higuchi models were found to be 0.777, 0.906 and 0.951, respectively.

Conclusion: The formulated enteric coated sodium alginate and pectin microbeads may be taken orally to deliver Norfloxacin and Tinidazole specifically to the colon for effective treatment of amoebiasis. The approach described appears promising for the colonic delivery of drugs.

Keywords: Alginate, colon targeting, Eudragit S100, HPMC, microbeads, norfloxacin, pectin, tinidazole.

Graphical Abstract