Objective:To determine the dissolution of SMZ and TMP from compound
sulfamethoxazole and trime-thoprim tablets of different
manufacturers,provide reference for ChP to set the standard for the dissolution of
compound sulfamethoxazole and trimethoprim tablets. Methods:Use HPLC method,the Diamosil C18 column(200 mm × 4. 6 mm, 5 μm) was used, and the mobile phase was methanol - buffer solution ( add 1 mL glacial acetic acid to 400 mL distilled water,and adjust pH to 7. 0±0. 1 by ammonia) (40: 60) ,the flow rate was 1. 0 mL·min ,detection wavelength was at 240 nm, injection volumn was 10 μL;Refer to ChP(2000) ,Appendix XC II ,compare the dissolution of compound
Sulfamethoxazole and trimethoprim tablets of different manufacturers in three kinds of medium: hydrochloric acid(9 →1 000) ,distilled water and pH 6. 8 phosphate buffer. Results:The linear response range from 100-500 μg· mL-1 of SMZ ( r = 0. 999 7 ) and 20 - 100 μg·mL-1 of TMP ( r = 0. 999 5 ) . The most significant difference was observed in the dissolution experiment using distilled water as release medium. Conclusion: The method is simple and accurate. It was suggested that the dissolution standard should be established in Chinese phar-macopia and distilled water be used as dissolution medium, detected by HPLC method.