US Patent 9452137 Pharmaceutical compositions comprising silica microspheres

A topical composition which includes a silica microspheres and an active ingredient in the amount of 0.01 to 15.0% w/w wherein the active ingredient is selected from adapalene, an antibiotic, tazarotene, tretinoin, a retinoid, or any combination thereof. The topical composition may also include benzoyl peroxide as an active ingredient. The topical compositions provide sustained release of the active ingredient so as to reduce skin irritation.