Abstract Bioequivalence (BE) assessment of topical drug products is a long-standing challenge. Agencies such as the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have published several drafts in recent years suggesting different approaches as alternative to evaluate the BE. A proposed Topical Classification System (TCS) has even been discussed. Given the above, the objective of this research was to use in vitro and in vivo BE approaches to evaluate Brazilian marketed mupirocin (MPC) ointments, previously classified as TCS class The in vitro permeation test (IVPT) was performed by applying formulations to pig skin by Franz cells. The in vivo methodology was dermatopharmacokinetic (DPK). These approaches (in vivo tape stripping and IVPT) demonstrated capability of distinguishing among different formulations, thus making them useful methodologies for BE evaluation.

ABSTRACT BACKGROUND: The World Health Organization has declared that a pandemic situation exists in relation to the disease caused by the new coronavirus, COVID-19. So far, the absence of a vaccine against the new coronavirus has led people worldwide to seek various therapeutic alternatives, including use of cholecalciferol. DESIGN AND SETTING: Narrative review developed by a research group at a public university in Recife (PE), Brazil. METHODS: We searched the literature on the use of cholecalciferol for prevention or treatment of COVID-19, using the MEDLINE and LILACS databases, with the keywords “vitamin D”, “cholecalciferol”, “SARS-CoV-2”, “COVID-19” and “coronavirus”, from January 1, 2020, to June 10, 2020. Narrative reviews, cohort studies and ecological studies were selected. RESULTS: We retrieved 32 references, of which 8 were considered eligible for intensive review and critical analysis. These comprised five narrative reviews, two observational studies and one protocol proposal. Most of the studies selected reported positive effects from use of vitamin D for prevention or treatment of COVID-19. However, there was little quantitative data to assess the real impact of using this vitamin as an intervention against this disease. CONCLUSIONS: Current studies on vitamin D used for purposes other than bone health promotion cannot be taken as support to justify its use in a disease as recent as COVID-19. Studies of greater robustness, with higher levels of clinical evidence, need to be conducted. Rational use of this vitamin needs to be ensured, thereby minimizing the impacts on the patient and the public healthcare system.

ABSTRACT Metronidazole (MTZ) is widely used as the standard antibiotic for the treatment of rosacea and, more recently, is being used off label in Brazilian hospitals for the treatment of wounds. Following oral administration, minimal amounts of active agent reaches the skin and side effects are strongly induced. Consequently, MTZ is currently being applied topically in order to improve the therapeutic efficacy with reduced side effects, with Rozex(r) (RZ) (an MTZ gelled formulation) being the only marketed product. This study examined whether the use of MTZ 0.75% from thermogel formulations could improve drug retention and reduce dermal exposure compared to that by Rozex(r). Following a 21 h permeation study, the highest total amount of MTZ permeated through the rat healthy and disturbed skin was seen with Rozex(r), but similar to all formulations regardless of the skin condition. On the other hand, the amount retained in the epidermis/dermis was larger for thermogel formulations; at least 4 fold that of Rozex(r), when the stratum corneum was present as a barrier. In conclusion, thermogel formulations can be favorable alternatives to Rozex(r) for the topical application of MTZ with improved efficacy and reduced side effects.