BASF offers a variety of products that enhance API permeation through the skin.
Skin Penetration Enhancement
The penetration of the API through the barrier of the stratum corneum is one of the challenges for developers of topical products designed for the dermal delivery of drugs through the skin. Numerous methods for achieving this have been and continue to be explored. One well-known approach is to use excipients that can accelerate the passage of API through the stratum corneum by altering the state of the lipids in the stratum corneum or by increasing the solubility of the drug in the stratum corneum. Materials that can do this are often called “penetration enhancers”. Classic examples of potent and broad spectrum penetration enhancers include Azone® and dimethyl sulfoxide, among others.
The ability of an excipient to accelerate stratum corneum permeation through the skin barrier is dependent on the physico-chemical properties (e.g. melting point, molecular weight, molecular geometry, charge, lipophilicity, etc.) of the API. For new APIs studies may need to be conducted to determine the optimal choice of penetration enhancer and/or full formulation to achieve desired dermal delivery.
Excipients that have been utilized or explored as penetration enhancers include isopropyl myristate (Kollicream® IPM), decyl oleate (Kollicream® DO), oleyl alcohol (Kollicream® OA), octyldodecanol (Kollicream® OD), propylene glycol (Kollisolv® PG) and triacetin (Kollisolv® GTA). Increasing evidence suggests that cocoyl caprylocaprate (Kollicream® 3C) may also accelerate the permeation of some APIs through the skin.