The characteristics and utility of solid phase porous microspheres: a review.

Topical drugs use a variety of ingredients to control the properties of the final product. Solid phase porous microspheres (SPPM, Microsponge) have been incorporated into several topical prescription products in an effort to improve performance or tolerability. SPPMs provide a reservoir effect allowing more prolonged skin exposure to the active ingredient. They are used in products for acne vulgaris, actinic keratoses, and pigmentary changes. The differences in clinical performance between existing formulations of these common active ingredients and the formulations using SPPMs are compared and contrasted.