Topical preparations and their use in dermatology.

The challenges of everyday clinical routine require dermatologists to have a basic knowledge of the composition of topical preparations as well as the regulatory background associated with their prescription. Proper selection, prescription, and application of topical preparations, depending on the respective indication, are key to professional and responsible medical practice. Problems commonly arise with respect to regulatory classifications (medicinal products, medical devices, or cosmetics), eligibility for reimbursement by the statutory health insurances (GKV), and insufficient declaration of vehicle systems. Apart from selecting the appropriate active substance and its proper concentration, choosing a suitable pharmaceutical (galenic) formulation - and thus utilizing the intrinsic effects thereof - is pivotal in enhancing the intended therapeutic effects. When prescribing individual formulations, dermatologists should, to the greatest extent possible, always resort to standardized extemporaneous preparations. Given the multitude of potential ingredients available for pharmaceutical formulations as well as the complexity resulting therefrom, arbitrary changes in quality or quantity of individual components are associated with a high risk of instability, thus jeopardizing safety and the rationale behind any given formulation. Optimal use of topical preparations also requires basic knowledge in pharmacokinetics as well as evidence-based treatment planning.