Physicochemical characterization of the metamorphosis of film-forming formulations of betamethasone-17-valerate.

Following topical application of a dermatological product, the loss (by evaporation and/or absorption through the skin) of volatile excipients will alter the composition of the formulation remaining on the tissue. This so-called metamorphosis impacts the concentration of the drug in the residual vehicle, (potentially) its physical form therein and, as a result, its uptake into and subsequent permeation through the skin. This research aimed to characterise - using primarily confocal Raman microspectroscopy - the metamorphosis of film-forming formulations of betamethasone-17-valerate (at different loadings) comprised of hydroxypropyl cellulose (film-forming agent), triethyl citrate (plasticizer) and ethanol (solvent).

Assessment of dermal bioavailability: predicting the input function for topical glucocorticoids using stratum corneum sampling.

Predicting the dermal bioavailability of topically delivered drugs is challenging. In this work, minimally invasive stratum corneum (SC) sampling was used to quantify the delivery of betamethasone valerate (BMV) into the viable skin. Betnovate® cream (0.

Skin Pharmacokinetics of Transdermal Scopolamine: Measurements and Modeling.

Prediction of skin absorption and local bioavailability from topical formulations remains a difficult task. An important challenge in forecasting topical bioavailability is the limited information available about local and systemic drug concentrations post application of topical drug products. Commercially available transdermal patches, such as Scopoderm (Novartis Consumer Health UK), offer an opportunity to test these experimental approaches as systemic pharmacokinetic data are available with which to validate a predictive model.

Stratum Corneum Sampling to Assess Bioequivalence between Topical Acyclovir Products.

Purpose: To examine the potential of stratum corneum (SC) sampling via tape-stripping in humans to assess bioequivalence of topical acyclovir drug products, and to explore the potential value of alternative metrics of local skin bioavailability calculable from SC sampling experiments.

Methods: Three acyclovir creams were considered in two separate studies in which drug amounts in the SC after uptake and clearance periods were measured and used to assess bioequivalence. In each study, a "reference" formulation (evaluated twice) was compared to the "test" in 10 subjects.