Drug Quality and Registration DruQuaR Group, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium
Department of Plastic and Reconstructive Surgery, University Hospital Ghent, De Pintelaan 185, B-9000 Ghent, Belgium
Department of Veterinary Medical Imaging and Small Animal 0rthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
Department of Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
Funds:
The Special Research Fund (BOF) of Ghent University to Lien Taevernier
The Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen) to Jente Boonen
Pharmaceutical excipients for topical use may contain impurities, which are often neglected from a toxicity qualification viewpoint. The possible impurities in the most frequently used topical excipients were evaluated in-silico for their toxicity hazard. Acetol, an impurity likely present in different topical pharmaceutical excipients such as propylene glycol and glycerol, was withheld for the evaluation of its health risk after dermal exposure. An ex-vivo in-vitro permeation study using human skin in a Franz Diffusion Cell set-up and GC as quantification methodology showed a significant skin penetration with an overall Kp value of 1.82 ? 10 ? 3 cm/h. Using these data, limit specifications after application of a dermal pharmaceutical product were estimated. Based on the TTC approach of Cramer class I substances, i.e. 1800 mg/(day?person), the toxicity-qualified specification limits of acetol in topical excipients were calculated to be 90 mg/mL and 180 mg/mL for propylene glycol and glycerol, respectively.