pH and Buffer Capacity of Topical Formulations.

Abstract

The pH is an important physicochemical factor that plays a significant role in various metabolic, molecular and cell-regulating processes. In the epidermis, the pH affects the barrier function on different levels. In many dermatoses that come along with an impaired barrier, shifts in the pH can be observed, and this is a problem that definitely needs to be addressed by finding appropriate galenic formulas when prescribing barrier protective basic care. With this in mind, 66 cosmetic preparations have been chosen following German market analysis. These preparations have been investigated regarding phase relation of the emulsion, absolute pH value and buffer capacity. The results show that only 23 preparations have an appropriate pH of ≤5.5 and only 3 preparations show a buffer capacity of ≥1.0. This outcome demonstrates the fact that the significance of pH and buffer capacity as quality criteria for barrier-protective preparations is still highly underrated from the view point of manufacturers and users.