Pharmacokinetic Comparison of Once-Daily Topical Minocycline Foam 4% vs Oral Minocycline for Moderate-to-Severe Acne.

OBJECTIVE: To characterize minocycline pharmacokinetics and relative bioavailability following multiple-dose topical administration of minocycline hydrochloride (HCl) foam 4% (FMX101 4%) as compared with single-dose oral administration of minocycline HCl extended-release tablets (Solodyn®) in subjects with moderate-to-severe acne.

METHODS: A Phase 1, single-center, nonrandomized, open-label, active-controlled, 2-period, 2-treatment crossover clinical study. The study included 30 healthy adults (mean age, 22.6 years; 90% white, and 60% females) who had moderate-to-severe acne. Subjects were assigned to first receive a single oral dose of a minocycline HCl extended-release tablet (approximately 1 mg/kg). At 10 days after the oral minocycline dose, topical minocycline foam 4% was applied, once daily for 21 days. Serial blood samples were obtained before and after administration of oral minocycline and each topical application of minocycline foam 4% on days 1, 12, and 21.

RESULTS: Following oral administration of minocycline (approximately 1 mg/kg), plasma minocycline concentration increased until 3 hours, followed by a log-linear decrease over the remainder of the 96-hour sampling period. Following topical application of a 4-g maximal-use dose of minocycline foam 4% for 21 days, plasma minocycline concentration was very low, with geometric mean Cmax values ranging from 1.1 ng/mL to 1.5 ng/mL. Steady state was achieved by day 6. Overall, minocycline exposure with topical minocycline foam 4% was 730 to 765 times lower than that with oral minocycline. There was no evidence of minocycline accumulation over the 21 days of topical application of minocycline foam 4%. Topical minocycline foam 4% appeared to be safe and well tolerated, with no serious treatment-emergent adverse events (TEAEs), treatment-related TEAEs, or TEAEs that led to treatment discontinuation.

CONCLUSION: Once-daily topical application of minocycline foam 4% did not lead to significant systemic exposure to minocycline. It appears to be a well-tolerated treatment option for individuals with moderate-to-severe acne. <p><em>J Drugs Dermatol. 2017;16(10):1022-1028.</em></p>.