BASF offers broad portfolio of solubilization polymers and solvents that have been used in FDA-approved transdermal patches, including, the Kollidon® CL series (crospovidones or cross-linked povidones), Kollidon®s (povidones of different molecular weights).
A critical quality attribute for transdermal patches is the ability to maintain API solubilization, and prevent recrystallization, throughout the specified lifetime of the patch. There are two classes of materials that can help to achieve this objective; solvents and solubilizers. At BASF Pharma Solutions, we define these as follows:
Solvents are well known as fluids into which crystalline material can be dissolved. Depending upon the design of the patch, these fluids can be formulated into the adhesive/polymer matrix in such a way that they maintain the homogeneous solubilization of the API. Examples of fluids that have been used in approved transdermal patch products include, Octyldodecanol (Kollicream® OD), isopropyl myristate (Kollicream® IPM), Oleyl alcohol (Kollicream® OA), Polysorbate 80 (Kolliphor® PS80), Triacetin (Kollisolv® GTA) and Propylene glycol (Kollisolv® PG). For the innovator, working on new drug applications or new patch technologies other fluids may be considered. BASF has a robust portfolio of hydrophilic and hydrophobic fluids to choose from.
Solubilizers are larger polymeric molecules that may be used to disperse and/or solubilize APIs, or to retard or prevent the crystallization of the API, in the finished patch. They can do this by:
In our portfolio we have numerous examples of polymers that have been used in FDA-approved transdermal patches, including, the Kollidon® CL series (crospovidones or cross-linked povidones), Kollidon®s (povidones of different molecular weights, i.e. Kollidon® 12 PF, Kollidon® 17 PF, Kollidon® 25, Kollidon® 30 and Kollidon® 90 F and Kollidon® VA64 (copovidone).