AQUEOUS, HEXANE AND ETHYL ACETATE EXTRACTS OF Chlorella vulgaris (Chlorellaceae) AS AN ALTERNATIVE PRESERVATIVE FOR AN ANTACID SUSPENSION

Chlorella vulgaris is a green plant-like, unicellular and spherical microscopic algae. The extract from C. vulgaris contains antioxidant and antimicrobial compounds (Dalton 2002). This study was conducted to assess the potential of C. vulgaris extracts as an alternative preservative for an antacid suspension. The antioxidant property of C. vulgaris was determined using the method of Yen and Chen (1995). Hexane, ethyl acetate and aqueous extracts of C. vulgaris (p=0.000) at 500 ppm, 100 ppm, 50 ppm, and 25 ppm exhibited incomparable antioxidant property with BHT. Ethyl acetate extract (500 ppm) showed the highest antioxidant activity while hexane extract (25 ppm) showed the lowest antioxidant activity, 12.65% and 3.23%, respectively. Still, most of the extracts exhibited inferior antioxidant activity compared with BHT. The formulated antacid suspension with aqueous extracts of C. vulgaris prevented the growth of S. aureus and E. coli up to 28 days as compared to propylparaben. Ethyl acetate and hexane extracts of C. vulgaris also showed reduction in bacterial growth. The decrease in the number of S. aureus and E. coli at 14th and 28th day indicates that C. vulgaris is a potential antimicrobial preservative. C. vulgaris conformed to the preservative standards of Category 4 products (USP 51).