Preparation and characterization of aqueous dispersions of dextrin and policosanol composites

Abstract

Policosanol (50-100mg) was dispersed in an aqueous solution (0.5-2.0% solids, w/v, 50 mL) of an amylomaize starch dextrin at 90°C under different conditions. The dispersion of the mixture was opaque but remained homogenous for up to 7 days at an ambient temperature. The precipitates obtained by centrifuging the dispersion (5,000 × g, 30 min) contained crystalline V-amylose complex of policosanol. The supernatant also contained policosanol but not in the complex form. Stepwise addition of policosanol and longer time complex formation increased the dispersible policosanol: about 95% by 30 min interval, 1.0% dextrin solution and 12h complex formation time. Among the dispersible policosanol (95%), 70% policosanol resided in the precipitates and 25% was in the supernatant, indicating the dextrin behaved as a stabilizer for the dispersed policosanol as well as a complex forming agent with policosanol. The policosanol dispersion was sonicated up to 30s to evaluate physical stability. Around 70% policosanol in the dispersion remained stable against the sonication treatment.

Keywords: Aqueous dispersion; Dextrin; Inclusion complex; Policosanol; V-amylose.