Pharmacology: Mechanism of Action: Clindamycin phosphate is the ester of clindamycin [7-(S)-chlorolincomycin], a semi-synthetic antibiotic. Clindamycin has been shown to have in vitro activity against isolates of Propionibacterium acnes. This may account for its usefulness in acne. Clindamycin has no fungicidal activity.
Pharmacokinetics: When applied topically, clindamycin has been shown to be absorbed from the skin in small amounts. Following multiple topical applications of clindamycin phosphate at a concentration equivalent to 10 mg clindamycin/mL in an isopropyl alcohol and water solution, very low levels of clindamycin are present in the serum (0-3 ng/mL) and <0.2% of the dose is recovered in urine as clindamycin.