The objectives of this study are to evaluate the therapeutic equivalence and safety of Clindamycin and Benzoyl Peroxide Gel 1%/5% (Taro Pharmaceuticals Inc.) and BenzaClin® (clindamycin 1%/benzoyl peroxide 5%) Topical Gel (Sanofi Aventis, US) in the treatment of acne vulgaris and to demonstrate the superiority of the efficacy of the test and reference products over the placebo control