Effect of pectin and kaolin on bioavailability of co-trimoxazole suspension

Bioavailability of co-trimoxazole suspension was determined with and without concurrent administration of pectin and kaolin in 8 volunteers. Twenty ml suspension of co-trimoxazole containing 160 mg trimethoprim (TMP) and 800 mg sulphamethoxazole (SMX) and co-trimoxazole suspension along with 20 ml of pectin-kaolin suspension were administered in a random order with 7 days interval. Plasma estimation of trimethoprim and sulphonamide was carried out at serial intervals. Area under curve (AUC) and Cmax of TMP were significantly higher when co-trimoxazole suspension alone was used. No statistically significant changes were observed in case of sulphamethoxazole. Clinical study is necessary to verify whether concurrent administration of co-trimoxazole and pectin-kaolin leads to loss of antibacterial efficacy.