Efficacy, safety, and tolerability of microsphere adapalene vs. conventional adapalene for acne vulgaris

BACKGROUND: The present study was undertaken to compare the efficacy, safety and tolerability of a new microsphere adapalene formulation and conventional adapalene in adult patients with mild to moderate acne vulgaris. MATERIALS AND METHODS: This prospective, randomized, assessor-blind, multi-centric (3 centres) comparative, post-marketing phase IV study was undertaken in 175 patients with mild to moderate acne after approval by respective Institutional review boards. Patients fulfilling selection criteria were randomly assigned to either microsphere adapalene gel or conventional adapalene gel both once daily in the evening for 12 weeks after obtaining their informed consent. Efficacy variables included success rate and percent lesion reduction from baseline. Safety and tolerability was assessed on the basis of physical examination and monitoring of treatment-emergent adverse events. RESULTS: Of the 175 patients (88 in microsphere and 87 in conventional) 21 were lost to follow-up and considered drop-outs. There was a significant decrease (P < 0.05) in mean inflammatory and non-inflammatory lesion and total lesion counts from 1st week onwards in both groups. A significantly lower number of microsphere treated patients (50%) reported a side effect (P < 0.05) as compared to 71.3% in conventional users. A highly significant decrease was observed in dryness and erythema (P < 0.01) in microsphere group compared to conventional. Eight patients in conventional group discontinued therapy due to severe irritation as compared to none in microsphere adapalene group. COMMENT: Therapy with microsphere adapalene provided a better tolerability with minimal irritation compared to conventional adapalene, without compromising efficacy and could be a better therapeutic option for acne.