Development and validation of a simultaneous analytical method for non-steroidal therapeutic compounds in cosmetics using liquid chromatography-tandem mass spectrometry.

Atopic dermatitis is a typical chronic inflammatory skin disease that affects all age groups and requires basic skin care for treatment. Anti-inflammatory and antiallergy steroids are the most frequently used treatments but they are limited due to their side effects caused by a weakening of the immune system. Many consumers focus on performance as a criterion for selecting cosmetics. However, steroids have been illegally used to improve the performance of cosmetics, and consumers have been adversely affected by the corresponding side effects. In this paper, we propose a simple and rapid method using liquid chromatography-tandem mass spectrometry to simultaneously analyze ten non-permitted atopic therapeutic compounds in cosmetic products: chlorpheniramine maleate, ketotifen fumarate, doxepin hydrochloride, azelastine hydrochloride, bufexamac, clotrimazole, tranilast, fusidic acid, tacrolimus, and pimecrolimus. Additionally, the major characteristic fragment ions for tacrolimus, pimecrolimus, and clotrimazole were identified by time-of-flight mass spectrometry. The specificity, linearity, limit of detection, limit of quantification, recovery, precision, accuracy, and stability of the proposed method were validated. The limit of detection and quantification were in the ranges of 5.05-203.30 pg/mL and 15.15-609.90 pg/mL, respectively. The proposed analysis method could help improve the safety management of cosmetics.

Opportunities for topical antimicrobial therapy: permeation of canine skin by fusidic acid.

BACKGROUND: Staphylococcal infection of the canine epidermis and hair follicle is amongst the commonest reasons for antimicrobial prescribing in small animal veterinary practice. Topical therapy with fusidic acid (FA) is an attractive alternative to systemic therapy based on low minimum inhibitory concentrations (MICs, commonly <0.03 mg/l) documented in canine pathogenic staphylococci, including strains of MRSA and MRSP (methicillin-resistant Staphylococcus aureus and S. pseudintermedius). However, permeation of canine skin by FA has not been evaluated in detail. This study aimed to define the degree and extent of FA permeation in canine skin in vitro from two sites with different hair follicle density following application of a licensed ophthalmic formulation that shares the same vehicle as an FA-betamethasone combination product approved for dermal application in dogs. Topical FA application was modelled using skin held in Franz-type diffusion cells. Concentrations of FA in surface swabs, receptor fluid, and transverse skin sections of defined anatomical depth were determined using high-performance liquid chromatography and ultraviolet (HPLC-UV) analysis. RESULTS: The majority of FA was recovered by surface swabs after 24 h, as expected (mean ± SEM: 76.0 ± 17.0%). FA was detected within 424/470 (90%) groups of serial sections of transversely cryotomed skin containing follicular infundibula, but never in 48/48 (100%) groups of sections containing only deeper follicular structures, nor in receptor fluid, suggesting that FA does not permeate beyond the infundibulum. The FA concentration (mean ± SEM) in the most superficial 240 µm of skin was 2000 ± 815 µg/g. CONCLUSIONS: Topically applied FA can greatly exceed MICs for canine pathogenic staphylococci at the most common sites of infection. Topical FA therapy should now be evaluated using available formulations in vivo as an alternative to systemic therapy for canine superficial bacterial folliculitis.

Detection and quantification of phytotoxic metabolites of Sarocladium oryzae in sheath rot-infected grains of rice.

AIMS: The present study describes the detection and quantification of the Sarocladium oryzae metabolites, helvolic acid and cerulenin in extracts of rice grains collected from plants infected with sheath rot. It also describes the phytotoxicity of these metabolites on rice seedlings. METHODS AND RESULTS: Helvolic acid and cerulenin in sheath rot-infected rice grains were detected using thin layer chromatography (TLC) and nuclear magnetic resonance (NMR) analyses. On the TLC plates helvolic acid and cerulenin moved as brownish yellow spots and showed R(F) values of 0.61 and 0.49, respectively. A standard assay curve was developed on the basis of selective toxicity of helvolic acid towards Calvibacter michiganensis ATCC 2140 and cerulenin towards Candida albicans 1150. The amounts of helvolic acid and cerulenin on the basis of standard assay curve were 2.2 and 1.75 microg g(-1) of infected seeds. Treatment of IR 36 rice seedlings with metabolites induced chlorosis and reduced shoot length by 20%, root length by 30% and root number by 7% relative to control. CONCLUSIONS: Helvolic acid and cerulenin were detected in infected rice grains and these metabolites induced chlorosis and reduced the seed viability and seedling health of rice. SIGNIFICANCE AND IMPACT OF THE STUDY: Antimicrobial and phytotoxic metabolites, helvolic acid and cerulenin are present in infected grains and reduce the seed viability and seedling health. These metabolites may increase the pathogenic potential and survival of S. oryzae in rice seed by competing with other seed-borne fungi.