Novel
tretinoin cream and gel formulations have been developed that incorporate
polyolprepolymer-2, which is a material designed to help retain
drug molecules in and on the skin when applied in topical vehicles. The results of preclinical and clinical investigations have confirmed the beneficial impact of such a vehicle on
tretinoin tolerability. In vitro studies with selected polyolprepolymer-containing formulations have reduced initial and cumulative
tretinoin percutaneous penetration, and guinea pig studies showed that the gel formulation containing
polyolprepolymer-2 caused less
erythema and
edema than did the corresponding commercially-available
tretinoin gel formulation. Human studies with
tretinoin containing
polyolprepolymer-2 have consistently demonstrated a favorable tolerability profile when compared with commercially-available
tretinoin. Use of the polyolprepolymer-2-containing
tretinoin formulation in human studies has resulted in reductions in peeling--a problem commonly associated with use of standard
tretinoin formulations. These reductions in irritation have not been at the expense of efficacy;
acne clinical trial results indicate comparable effectiveness between
tretinoin containing polyolprepolymer2 and commercially-available
tretinoin.