Essential Oils for Treatment for Onychomycosis: A Mini-Review.

Onychomycosis are fungal infections affecting finger and toenails mainly caused by dermatophyte fungi and some Candida species. Low cure rates and frequent recurrence, development of a fungal resistance front to various antimicrobial agents topical and systemic, and an ineffective topical treatment make onychomycosis difficult to treat. Essential oils are excellent candidates for the topical treatment for onychomycosis because the development of resistance by fungi is rare, and the presence of side effects is low. They are composed of a complex variety of compounds, mainly terpenes, with low molecular weight, which may easily penetrate into the nail plate, finding the fungi elements. The complex mixture confers a broad antifungal spectrum of action, through interaction with biological membranes, interference in radical and enzymatic reaction of fungi cells. Essential oils may become the source of new therapeutic molecules, and the use of an essential oil incorporated into a topical formulation is an interesting, safe, and effective alternative for the treatment for onychomycosis. However, studies are needed to evaluate the efficacy of essential oils in the treatment for onychomycosis in vivo. This mini-review aims to present the potential use of essential oils for the treatment for onychomycosis, focusing on the last decade.

Hydrogels Containing Nanocapsules and Nanoemulsions of Tea Tree Oil Provide Antiedematogenic Effect and Improved Skin Wound Healing.

In previous works, we developed nanocapsules and nanoemulsions containing the tea tree oil. The aim of this work was to prepare and characterize hydrogels containing these nanocarriers, and to evaluate their in vivo efficacy in protecting skin damage induced by UVB and cutaneous wound healing. Hydrogels were prepared using Carbopol Ultrez and their physicochemical characteristics were evaluated: macroscopic analysis, pH, spreadability and rheological properties. The in vivo antiedematogenic effect was evaluated by ear thickness measurement after UVB-irradiation. In order to evaluate healing action of hydrogels, we investigated the regression of the cutaneous lesion in rats. Hydrogels showed homogeneous aspect and pH values between 5.6-5.8 and a non-Newtonian behavior. The presence of nanocapsules and nanoemulsions in hydrogels did not change their spreadability profile. The inclusion of tea tree oil in the nanocapsules and nanoemulsions allowed reducing the edema induced by UVB exposure. Hydrogel containing nanocapsules presented a higher reduction of the wound area compared to the hydrogel containing nanoemulsions and hydrogel containing allantoin. This study shows the feasibility of obtained dermatological formulations containing the tea tree oil associated in nanostructured systems. These formulations represent a promising approach to topical treatment of inflammatory disorders and wound healing.

Enhancement of tioconazole ungual delivery: Combining nanocapsule formulation and nail poration approaches.

This work investigated the impact of formulation including in vitro release profile, repeated dosing, and nail poration on the ex vivo nail delivery performance of antifungal formulations. Chitosan coated and uncoated tioconazole-loaded nanocapsules and a nano-based film-forming vehicle were assessed via in vitro release and in vitro permeation tests using an artificial membrane and human nail clippings, respectively. The later involved single and daily dosing experiments with intact and porated nails. Additional experiments with Nile Red-loaded formulations evaluated the depth of penetration of the fluorescent marker into the nail by laser scanning confocal microscopy. The nanocapsule formulations prolonged release of tioconazole for longer than the control solutions and this ability was related to an enhanced nail penetration of the drug. Further, the new film-forming formulation delivered its drug payload more efficiently than a marketed product. Daily dosing of the formulations doubled the amount of drug recovered from the nails. Porating the nails enhanced tioconazole delivery in single dose experiments only. The depth of penetration of Nile Red into the nails clippings ranged between 90-160 µm. This research suggests that ensuring prolonged release of a drug is fundamental to develop efficacious topical nail formulations.

An innovative polysaccharide nanobased nail formulation for improvement of onychomycosis treatment.

Tioconazole-loaded nanocapsule suspensions and its coating with a cationic polymer were developed for nail drug delivery. The colloidal systems presented a nanometric size around 155nm for uncoated nanoparticles and 162nm for those with the cationic coating, with negative and positive zeta potential values, respectively. Both nanosuspensions showed drug content close to theoretical values (1mgmL-1), association efficiency close to 100% (HPLC) and were able to control tioconazol release. The developed formulations showed in vitro antifungal activity (agar diffusion method) against C. albicans. The cationic nanocapsules were considered bioadhesive, showed higher viscosity and were chosen to be incorporated into an ungueal formulation. Pullulan nanobased nail formulation showed adequate viscosity for nail application and drug content close to the theoretical values. It was equivalent to the commercial formulation Trosid® in preventing nail infection by T. rubrum in an in vitro onychomycosis model. The nanocapsule suspensions and Pullulan nanobased nail formulation showed lower irritant potential than the commercial formulation and than free drug in an in vitro evaluation. Pullulan nanobased nail formulation is promising for the treatment of onychomycosis.

Ácaros da poeira domiciliar: correlação entre as espécies e a doença alérgica / Mites in the house dust: correlation between species and allergic disease

Os ácaros são considerados a maior fonte de alérgenos inalantes envolvidos em doenças alérgicas respiratórias. Com o objetivo de correlacionar os ácaros mais prevalentes na poeira domiciliar aos agentes etiológicos mais comuns da população atópica, realizamos um estudo randomizado, prospectivo e pioneiro no município de Bragança Paulista, entre abril de 1998 e setembro de 1999. Nas amostras de poeira encontramos as espécies D. pteronyssinus (55,36 por cento), família Tarsonemidae (16,96 por cento) e B. tropicalis (12,80 por cento). Dos 90 voluntários testados com o prick teste encontramos 71 por cento de positividade aos alérgenos poeira doméstica (60 por cento), D. pteronyssinus (56,70 por cento) e B. tropicalis (51,10 por cento). A família Tarsonemidae assume um lugar de destaque entre as espécies encontradas, fato incomum na bibliografia pesquisada