Nanoparticle delivery for transdermal HRT

Abstract

Nanomedicine is an emerging technology and the first nano-engineered medical products have come to light in the last decade. Transdermal drug delivery has significant advantages compared to other routes of drug administration. Nanoparticles unique physical and chemical properties enable transport of substances directly into the skin. The objective of this paper is to review different aspects of nanoparticle delivery, generally, and discuss its current use for transdermal hormone therapy. Transdermal estrogen therapy remains the most effective treatment for bothersome menopausal symptoms, particularly in those women for whom the potential adverse effects associated with "first pass" hepatic metabolism are to be avoided. Available alternatives for transdermal estrogen delivery include patches, gels, sprays and lotions. Other non-oral therapies which likewise avoid "first pass" hepatic metabolism include: subcutaneous implants and vaginal rings. Some of the transdermal products are associated with mild adverse skin effects such as redness and irritation, but more severe and bothersome consequences include blistering and tattooing. Even the mild adverse skin effects are frequently cited as reasons for discontinuation. Micellar nanoparticle estradiol emulsion (MNPEE) is a lotion-like therapy which constitutes an alternative transdermal delivery system not requiring the permeation enhancers or temporary skin digestion, both of which increase the possibility of irritation. MNPEE's advantages include low fluctuation of plasma estradiol concentrations, infrequent skin related adverse effects, and pleasant cosmetic-like moisturizing properties. The efficacy of MNPEE for management of menopausal vasomotor symptoms has been demonstrated in a randomized placebo controlled trial, and the product is FDA approved for management of moderate to severe vasomotor symptoms. None of the observed adverse effects in the MNPEE group were statistically different from the placebo group. Studies addressing inadvertent transference of estradiol to the male partners of menopausal women using this delivery technology have demonstrated small, but real amounts of transference, which do not exceed the normal physiological male estradiol range. MNPEE is safe and effective for treatment of vasomotor symptoms and represents the commercial validation of nanoparticle technology for transdermal delivery of estrogen therapy (ET) for postmenopausal women with vasomotor symptoms.

Nano-TiO2modulates the dermal sensitization potency of dinitrochlorobenzene after topical exposure

“…Skin exposure and potential penetration of nanoparticles can both be desirable (transdermal drug delivery) or undesirable (negative health effects). 4,19 Dermal exposure can occur by applying cosmetics containing ENPs, during handling of nanoparticle-containing products (e.g. paints, clothing) or through water or even air contaminated with ENPs.…”

Polymeric micelles for cutaneous drug delivery

“…Polymeric micelles provide several advantages, such as their nano-size, ease of scale-up studies, increased drug solubility and chemical stability. Given these advantages, there has been much research into their use as drug and gene delivery systems via parenteral [13,14], oral [15,16], nasal [17,18], ocular [19,20], and topical/transdermal [21,22] applications.…”

Recent Advances in Physical Approaches for Transdermal Penetration Enhancement

“…NPs can either remain intact or degrade near the skin surface releasing active substance to penetrate into skin layers. The mechanism of penetration of NPs across skin is related to their size, surface area, surface charge, drugloading efficiency, lamellarity and mode of application [110]. A wide-ranging spectrum of nanocarriers, extending from various lipid nanostructures such as liposomes, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), to nanocrystalline, polymer particles and vesicular carriers such as transferosomes, have already been tested as drug delivery systems with remarkable results [111].…”