Foams can be produced using two distinct technologies:
- In an aerosol using propellant gas, the formulation consists of an emulsion. The creamy foam obtained is suitable for damaged or sensitive skin (e.g., psoriasis or atopy).
- In a propellant-free device, the formulation consists of a microemulsion. The light texture obtained is suitable for quick absorption without residue and is convenient for hair-bearing skin. It may, for example, be used with disinfectant or anti-inflammatory drugs.
Excipients for propellant device emulsion formulation:
Tefose® 63 is an O/W emulsifier with foaming capacity and high mucosal tolerance. It is often used in combination with Labrafil® M 1944 CS as a co-emulsifier and Transcutol® P as solvent.
Excipients for propellant-free device micro-emulsion formulation:
Labrasol® is a good solubilizer with foaming capacity. It is often used in combination with Plurol® Oleique CC 497 as cosurfactant and Labrafac® Lipophile WL 1349 as an oily vehicle and emollient.
Gattefossé can provide formulation tips for pharmaceutical foams using propellant and propellant-free devices, guidelines on how to formulate and select excipients, and case studies with model drugs.
