Tolnaftate is a thiocarbamate antifungal drug which is therapeutically active against dermatophytes that cause various forms of tinea. Due to the small amount of tolnaftate released from ordinary ointment bases and insufficient penetration through the infected skin layers the need to incorporate the drug in a more suitable pharmaceutical form has evolved. A provesicular system is one such form that can solve these problems. Once in contact with the skin, dilution with moisture occurs and the provesicular system rapidly transforms into a vesicular one. Provesicular systems were prepared according to full-factorial experimental design. Plain provesicular systems were compared with systems containing Phospholipon 80 H and Lipoid S45 as penetration enhancers. Design expert software was used to analyze the effect of formulation variables (type of Span used as well as the presence or the absence of the penetration enhancer and its type) on the dependent variables: percent encapsulation efficiency (EE%), vesicle size and percent in vitro drug released). Three formulations were chosen; a plain provesicular system (PV-2), one containing Phospholipon 80H (PV-6) and another containing Lipoid S45 (PV-10) with the goal to reveal the effect of penetration enhancer on morphology, rheological properties and ex vivo permeation using confocal laser scanning microscopy (CLSM). Analysis of CLSM results showed that the penetration enhancing effect for the tested formulations followed the order PV-10 > PV-6 > PV-2. Promising clinically active treatment for tinea patients could be expected as shown by the in vivo permeation results for the provesicular systems as suggested by the CLSM results.

In vitro susceptibilities of 100 clinical dermatophyte isolates belonging to five species from Iran toward lanoconazole and luliconazole were compared with ten other antifungal agents including econazole, itraconazole, miconazole, fluconazole, griseofulvin, butenafine, terbinafine, caspofungin, anidulafungin and tolnaftate. MIC and MEC values were analyzed according to CLSI M38-A2 document. The isolates were previously identified to the species level using PCR-RFLP on ITS rDNA region. The range of luliconazole and lanoconazole minimum inhibitory concentrations (MICs) was 0.016-0.032 and 0.063-1 μg/ml, respectively for dermatophyte species. Luliconazole and lanoconazole revealed potent activity against all dermatophyte isolates. Anidulafungin, caspofungin, and luliconazole showed the best activity with the lowest geometric mean 0.01, 0.016, and 0.018 μg/ml, respectively, followed by tolnaftate (0.06 μg/ml), terbinafine (0.07 μg/ml), itraconazole (0.183 μg/ml), butenafine (0.188 μg/ml), econazole (0.20 μg/ml), lanoconazole (0.24 μg/ml), griseofulvin (1.28 μg/ml), miconazole (2.34 μg/ml) and fluconazole (15.34 μg/ml). The current study demonstrated luliconazole and lanoconazole displayed excellent activity against all dermatophyte isolates, although the majority of dermatophyte isolates showed low susceptibility to griseofulvin and very low to miconazole, and fluconazole.

A highly selective, sensitive, accurate, and reproducible luminescence procedure for determination of antifungal drug tolnaftate was developed. The introduced method was based on the formation of Europa Universalis III (Eu(III))-tolnaftate complex using sodium sulfite as a deoxygenated agent in the presence of acetate buffer (pH = 6) and micellar solution of anionic surfactant sodium dodecyl sulfate. The optimum conditions (effect of pH, buffer, surfactant, Eu(III), and sodium sulfite concentrations) for the luminescence signal were investigated and optimized. The luminescence signals were recorded at λex = 270 nm and λem = 460 nm. The method has a good linear response (0.2-130 μg/mL(-1)) between the luminescence intensity and the concentrations of the drug (r = 0.999), with a LOD 0.07 μg/mL(-1) and LOQ 0.2 μg/mL(-1). The luminescence signals of Eu (III)-tolnaftate-sodium dodecyl sulfate were found to be 200-fold more sensitive without the presence of micelle solution. The interferences of some additives, metals, amino acids, sugars, and other related pharmacological action drugs were examined and no interference was recorded. The proposed method was used for quick and simple determination of tolnaftate in its pharmaceuticals and biological fluids.

Fatty acids classified as chemical penetration enhancers (CPEs) might cause the fluidization and perturbation of stratum corneum (SC) lipid matrix. The penetration of oleic, linoleic, lauric and capric acids into human skin was studied by time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging and related to fatty acids enhancing effect on lipophilic model drug tolnaftate penetration into human epidermis and dermis ex vivo. Fatty acid enhancing effect on tolnaftate penetration into human skin was evaluated using Bronaugh-type flow-through diffusion cells. After in vitro penetration studies visualization and spatial localization of fatty acid molecules in human skin were performed using TOF-SIMS. Penetration of oleic, linoleic, lauric and capric acids into human skin was compared to the control skin sections by ion images and intensity profiles. Only oleic acid significantly (P<0.05) enhanced tolnaftate penetration into epidermis (enhancing ratio equal to 1.867). CPE might have no effect on model drug penetration enhancement, but might penetrate itself into the skin.

Gray mold, caused by the fungal pathogen Botrytis cinerea, is one of the most destructive diseases of strawberry. Control of the disease in commercial fields is largely dependent on the application of fungicides, including the dicarboximide iprodione. Single-spore isolates were collected from strawberry fields in Florida, North Carolina, and South Carolina and subjected to an assay using conidial germination that distinguished sensitive (S) isolates from isolates with various levels of resistance to iprodione. Of the 245 isolates, 1 was highly resistant (HR), 5 were moderately resistant (MR), and 43 had low resistance (LR) to iprodione. LR and MR strains were found in the Florida population and in 9 of 11 locations from North Carolina and South Carolina, indicating that resistance was widespread but accounted for only a relatively small percentage of the B. cinerea population. Sequence analysis of the target gene bos1, which codes for a class III histidine kinase, revealed that the MR phenotype was associated with Q369P and N373S mutations and that the LR phenotype was associated with either a I365S or a I365N mutation. The I365S and I365N mutations were also present in five additionally included HR isolates from North Carolina and South Carolina blackberry fields and one HR isolate from a Virginia strawberry field but no mutation or mutation combinations in bos1 were uniquely associated with the HR phenotype. Expression analysis of bos1 in S and HR isolates did not reveal convincing evidence of the gene's involvement in HR resistance either. The six HR isolates had three different phenotypes with respect to their sensitivity to fludioxonil; two were S, two were LR, and two were MR. The fludioxonil LR and MR isolates were also resistant to tolnaftate, an indication of multidrug efflux pump activity. These data suggest that, in addition to point mutations in bos1, drug efflux pump activity and potentially a third mechanism of resistance may be contributing to the iprodione HR phenotype. Detached fruit studies showed that field rates of Rovral 4 Flowable (iprodione) did not control iprodione MR and HR isolates.

Storage of pharmaceutical discovery compounds dissolved in dimethylsulfoxide (DMSO) is commonplace within industry. Often, the DMSO stock solution is added to an aqueous system (e.g. in bioassay or kinetic solubility testing)- since most test compounds are hydrophobic, precipitation could occur. Little is known about the factors affecting this precipitation process at the low (µM) concentrations used in screening analyses. Here, a poorly water soluble test compound (tolnaftate) was used to compare manual and automated pipetting, and explore the effect of mixing variables on precipitation. The amount of drug present in the supernatant after precipitation and centrifugation of the samples was quantified. An unusual result was obtained in three different laboratories: results of experiments performed initially were statistically significantly higher than those performed after a few days in the same lab. No significant differences were found between automated and manual pipetting, including in variability. Vortex mixing was found to give significantly lower supernatant amounts compared to milder mixing types. The mixing employed affects the particle growth of the precipitate. These findings are of relevance to discovery stage bioassay and kinetic solubility analyses.