Abstract
Topical clindamycin is used in the treatment of acne vulgaris at this time. In hospital pharmacy, 1 % clindamycin phosphate lotion for acne vulgaris is prepared from the injectable form of clindamycin phosphate dissolved in the hydroalcoholic vehicle.
Stability of the preparation and 1% clindamycin phosphate aqueous solution was studied at 5° and 25° for 180 day. The pH of the sample was observed along with a periodical visual inspection. The amount of clindamycin phosphate in solution was determined by reversed-phase ion-pairing high-performance liquid chromatography (HPLC) with UV detector at 210 nm.
1% clindamycin phosphate lotion maintained 92% of its activity during the period of 180 days at 5°, and 88 % at 25°.1 % clindamycin phosphate aqueous solution retained 91 % of its activity over the period of 180 days at 5°, and 90% at 25°. As a primary degradation product of clindamycin phosphate in solution, lincomycin-2-phosphate was found in small amount.
1% clindamycin phosphate lotion is relatively stable and good for more than 180 days at 5°.
