For non-inflammatory lesions, the mean percent reduction was 25% for clindamycin phosphate gel and 12% for the vehicle gel. The total mean percent reduction in lesion counts at the end of treatment was 38% for clindamycin phosphate gel and 27% for the vehicle gel.In a contact sensitization trial, four of the 200 subjects appeared to develop suggestive evidence of allergic contact sensitization to clindamycin phosphate gel.There was no signal for contact sensitization in the clinical trials under normal use conditions.he total mean percent reduction in lesion counts at the end of treatment was 38% for clindamycin phosphate gel and 27% for the vehicle gel. In a contact sensitization trial, four of the 200 subjects appeared to develop suggestive evidence of allergic contact sensitization to clindamycin phosphate gel.