[Regulatory requirements for topical preparations]. / Regulatorische Besonderheiten für Topika.

Professional use of topical treatment in dermatological practice requires not only knowledge about the pharmacological properties, efficacy, safety and pharmaceutical quality of a preparation, but also about its regulatory classification. The latter essentially determines the physician's prescription practice and therapeutic freedom. The regulatory framework with which one is confronted unfortunately lacks transparency. It regulates not only the prescribability and reimbursability of proprietary medicinal products and extemporaneous preparations, but also the obligation to give information as well as the details of liability of both the prescriber (physician) and the manufacturer (pharmaceutical company or pharmacist). The prescriber needs to be aware of to what extent the pharmacist has the possibility and even obligation to change the prescribed preparation. In some cases this can directly affect the therapeutic concept of the physician and even impair the effectiveness and safety of the chosen therapy.

[In vitro measurement of digitalis-like compounds by inhibition of Na+ K+-ATPase: determination of the inhibitory effect]. / In vitro-Messung digitalisähnlicher Verbindungen durch Hemmung des Enzyms Na+/K(+)-ATPase: Bestimmung von Störeinflüssen.

The linked optical test for the analysis of digital-like substances with the enzyme Na+/K(+)-ATPase was investigated with regard to inhibition by components of the reaction medium. Most of the tested inorganic salts influenced the activity of the enzyme. However, the concentrations of the salts in human tissues and fluids are too small to cause measurable effects. Higher concentration of salts, which may be obtained by the preparative treatment of clinical material can influence the test. The determination of a reference value is recommended in these cases. The organic solvents DMSO and Methanol influenced the activity of the Na+/K(+)-ATPase, too. While the influence of DMSO in concentrations below 50% (v/v) was negligible, the measurement of a reference sample at higher DMSO concentrations and for methanolic samples is necessary.