Topical antifungal-corticosteroid combination therapy for the treatment of superficial mycoses: conclusions of an expert panel meeting

Drilling down the bioequivalence assessment of topical antifungal products: Microstructure and release

In recent years, the regulatory mechanisms for topical generic product bioequivalence (BE) assessment have been subjected to noteworthy changes, with the FDA issuing product specific guidances, and the EMA adopting a more universal approach with the quality and equivalence of topical products draft guideline. The agencies advise on a modular strategy for BE documentation. Nevertheless, their scope, data analysis and criteria are rather distinct. This study aims to tackle bioequivalence assessment issues of complex topical formulations starting by statistical implications of the EMA/FDA approaches concerning the documentation of qualitative (Q1), quantitative (Q2), microstructure (Q3) and performance requirements (Q4). As a model drug product, a bifonazole 10 mg/g cream formulation was selected. For this specific formulation, the commercially available Reference Product (RP) was compared with two comparator products, also commercially available, referred to as comparator product A (CPA) and comparator product B (CPB). The former displays Q1 sameness and Q2 differences, whilst CPB is categorically considered as Q1/Q2 different. Furthermore, intending to establish a regulatory rationale for the submission of a generic product according to the updated regulatory requirements, the RP was likewise compared with a Test Product (TP). This formulation was designed to display equal Q1/Q2 profile to that of the RP. Validated rheology and in vitro release test (IVRT) methods were used to infer on Q3/Q4 characteristics. During rheology studies, statistically significant RP batch to batch differences were observed. Therefore, in an attempt to surpass this heterogeneity, the initial pool of RP batches was expanded to include RP product batches at different lifecycle stages. Despite this effort, it was not possible to classify the RP/TP, RP/CPA or RP/CPB as rheologically equivalent products. Nevertheless, product performance results, retrieved from IVRT, were able to sustain equivalence between the RP and the formulations exhibiting Q1 sameness (TP and CPA). It should however be mentioned, that for some RP batch combinations, the IVRT results failed to demonstrate equivalence according to the EMA requirements. Enlarging the RP batch pool was then a critical step in further understanding an optimum statistical approach for establishing equivalence in product performance. This study highlights the need to that a 'one-fits-all approach' may not be an optimum path way for establishing the regulatory strategy and requirements to support generic product bioequivalence.

Emerging Trends in the Use of Topical Antifungal-Corticosteroid Combinations

A broad range of topical antifungal formulations containing miconazole or terbinafine as actives are commonly used as efficacious choices for combating fungal skin infections. Their many benefits, owing to their specific mechanism of action, include their ability to target the site of infection, enhance treatment efficacy and reduce the risk of systemic side effects. Their proven efficacy, and positioning in the treatment of fungal skin infections, is enhanced by high patient compliance, especially when appropriate vehicles such as creams, ointments and gels are used. However, inflammation as a result of fungal infection can often impede treatment, especially when combined with pruritus (itch), an unpleasant sensation that elicits an urge to scratch. The scratching that occurs in response to pruritus frequently accelerates skin damage, ultimately aggravating and spreading the fungal infection. To help overcome this issue, a topical antifungal-corticosteroid combination consisting of miconazole or terbinafine and corticosteroids of varying potencies should be used. Due to their inherent benefits, these topical antifungal-corticosteroid combinations can concomitantly and competently attenuate inflammation, relieve pruritus and treat fungal infection.

Presumptive Zoonotic Kerion by Nannizzia gypsea: Case Report

Nannizzia gypsea (formerly Microsporum gypseum) belongs to geophilic dermatophytes, fungi involved in keratin degradation in the soil; however, they are also found in dogs and cats. Transmission to humans can occur directly by contact with soil, but indirect transmission via domestic animals is reported too. The exact source of the infection is usually difficult to assess and in most cases only hypothesised and rarely investigated. This case report describes a kerion caused by N. gypsea in a 2-year-old boy, where the contagion was probably secondary to domestic healthy carrier dogs. A “One-Health” approach involving human dermatologists and veterinarians, combined with the use of conventional and molecular-based techniques, allowed tracing of the epidemiological chain and managing of not only the treatment but also the prevention of a recurrence. The child's lesion began to regress after about 8 weeks of treatment with both systemic and topical therapy, while the dogs were given chlorhexidine and miconazole baths. No recurrences nor new infections occurred, demonstrating the effectiveness of the strategies used.

Topical antimicrobial prescribing patterns in residents of Australian aged-care facilities: use of a national point prevalence survey to identify opportunities for quality improvement

BACKGROUND

Australian residential aged care facilities (RACFs) are encouraged to participate in an annual Aged Care National Antimicrobial Prescribing Survey. This data source was analysed to describe patterns of topical antimicrobial prescribing and thereby provide insight into antimicrobial stewardship (AMS) changes that might be required.

METHODS

2018 and 2019 survey data was analysed.

RESULTS

The overall prevalence of the 52,431 audited residents (629 facilities) who were prescribed 1 or more topical antimicrobials was 2.9%. Of all prescribed antimicrobials (n=4899), 33.0% were for topical application. Most frequently prescribed topical antifungals were clotrimazole (85.3%) and miconazole (9.1%), and antibacterials chloramphenicol (64.1%) and mupirocin (21.8%). Tinea (38.3%) and conjunctivitis (23.8%) were the 2 most common indications. Topical antimicrobials were sometimes prescribed for pro re nata administration (38.8%) and greater than 6 months (11.3%). The review or stop date was not always documented (38.7%).

CONCLUSIONS

To reduce the possibility of adverse consequences associated with antimicrobial use, antimicrobial stewardship programs in Australian residential aged care facilities should at least ensure mupirocin is appropriately used, first line antimicrobial therapy is prescribed for tinea, chloramphenicol is prescribed for conjunctivitis only if necessary, pro re nata orders for prescriptions are discouraged and to avoid prolonged duration of prescriptions, review or stop dates are always documented.

S1 guidelines: Tinea capitis

Tinea capitis describes a dermatophyte infection of scalp and hair that predominately occurs in children. The diagnostic workup includes microscopic examination, culture and/or molecular tests. Treatment is guided by the specific organism involved and should consist of systemic agents as well as adjuvant topical treatment. The aim of the present update of the interdisciplinary German S1 guidelines is to provide dermatologists, pediatricians and general practitioners with a decision tool for selecting and implementing appropriate diagnostic and therapeutic measures in patients with tinea capitis. The guidelines were developed based on current international guidelines, in particular the 2010 European Society for Pediatric Dermatology guidelines and the 2014 British Association of Dermatologists guidelines, as well as on a review of the literature conducted by the guideline committee. This multidisciplinary committee consists of representatives from the German Society of Dermatology (DDG), the German-Speaking Mycological Society (DMykG), the German Society for Hygiene and Microbiology (DGHM), the German Society of Pediatric and Adolescent Medicine (DGKJ) and the German Society for Pediatric Infectious Diseases (DGPI). The Division of Evidence-based Medicine (dEBM) provided methodological assistance. The guidelines were approved by the participating medical societies following a comprehensive internal and external review.

Updates on Genital Dermatophytosis

Dermatophytes are a group of keratinophilic fungi, which normally cause superficial infection of skin, hair and nails. Based on ecology, they are classified into three groups: anthropophilic, zoophilic and geophilic. Superficial dermatophytic infection of the genital region is called genital dermatophytosis, tinea genitalis or pubo-genital dermatophytosis. In this review, we would like to discuss briefly, the various clinical presentations of genital dermatophytosis, current changes in the taxonomy and nomenclature, introduction of new diagnostic techniques and briefly describe some common dermatophytes and their sources. Also, there are serious concerns associated with the recent development of antifungal resistance among the dermatophytes. We are also facing the scenario of hard-to-treat dermatophytosis.

Simultaneous HPLC Determination of Betamethasone Esters-Containing Mixtures: Analysis of Their Topical Preparations

Topical pharmaceutical preparations containing betamethasone esters are widely prescribed for treatment of severe inflammatory skin conditions. Some betamethasone esters-containing preparations are formulated with either an antibacterial or an antifungal agent or a vitamin D3 derivative. A fast reversed-phase high-performance liquid chromatography method has been developed for the simultaneous determination of three betamethasone esters-containing binary mixtures along with the excipients of their dosage forms using clobetasone butyrate as internal standard. The first mixture was betamethasone valerate and fusidic acid (Mixture I) with chlorocresol as preservative. The second mixture was betamethasone dipropionate (BTD) and clotrimazole (Mixture II) with benzyl alcohol as preservative. The third mixture was BTD and calcipotriol monohydrate (Mixture III). Optimized chromatographic separation was achieved on a Discovery® C18 (4.6 × 250 mm, 5 μm) column, using water: acetonitrile (35:65, v/v) as mobile phase at flow rate of 1 mL/min with UV detection at 230 nm. The method was validated according to ICH guidelines. The regression coefficients were > 0.999 for all drugs. The method was successfully applied for the determination of the studied drugs in bulk, synthetic mixtures and dosage forms. The developed method is accurate, sensitive, selective and precise and can be used for routine analysis in quality control laboratories.