Use of Minoxidil Sulfate versus Minoxidil Base in Androgenetic Alopecia Treatment: Friend or Foe?

Efficacy, Tolerability, and Superiority of Propylene Glycol-Free, North American Witch-Hazel (Hamamelis virginiana)-Based Solution of 5% Minoxidil Sulfate for the Treatment of Female Androgenetic Alopecia

Background

Androgenetic alopecia leads to progressive hair loss in susceptible individuals if left untreated. Topical minoxidil represents an evidence-based treatment for female androgenetic alopecia, though with variable success.

Aims and Objectives

Treatment of minoxidil non-responders remains challenging, as does treatment of patients with propylene glycol sensitivity or irritable scalp syndrome.

Materials and Methods

Single-center, retrospective cohort of 50 female patients with androgenetic alopecia failing to respond to a minimum of 6 months of standard 5% topical minoxidil solution either once daily or b.i.d. depending on the severity of the alopecia. Patients were switched to propylene glycol-free, North American Witch Hazel (Hamamelis virginiana)-based solution of 5% minoxidil sulfate (5% minoxidil sensitive solution). Efficacy and safety of treatment were evaluated, including stereotactic global photography and epiluminiscence microscopy with digital imaging taken at baseline, at 3, and at 6 months of treatment.

Results

70% of patients showed observable clinical improvement with combined global photographic and epiluminiscence microscopic assessment with digital imaging, and 22% epiluminiscence microscopic-only improvement as evidence of treatment efficacy. The treatment was well tolerated, particularly in patients with propylene glycol sensitivity and patients with irritable scalp syndrome.

Conclusions

These results suggest that propylene glycol-free, North American witch hazel (Hamamelis virginiana)-based solution of 5% minoxidil is effective and safe for treatment of female androgenetic alopecia, specifically in minoxidil non-responders and patients with propylene glycol sensitivity or irritable scalp syndrome.

Female pattern hair loss: therapeutic update

Female androgenetic alopecia or female-pattern hair loss (FPHL) is highly prevalent and has a great impact on the quality of life. The treatment is a routine challenge in dermatological practice, as many therapeutic options have a limited level of evidence and often do not meet patients expectations. Lack of knowledge of the pathogenesis of the hair miniaturization process and the factors that regulate follicular morphogenesis restricts the prospect of innovative therapies. There is also a lack of randomized, controlled studies with longitudinal follow-up, using objective outcomes and exploring the performance of the available treatments and their combinations. Topical minoxidil, which has been used to treat female pattern hair loss since the 1990s, is the only medication that has a high level of evidence and remains the first choice. However, about 40% of patients do not show improvement with this treatment. In this article, the authors critically discuss the main clinical and surgical therapeutic alternatives for FPHL, as well as present camouflage methods that can be used in more extensive or unresponsive cases.

Nanostructured lipid carriers loaded with an association of minoxidil and latanoprost for targeted topical therapy of alopecia

Alopecia is a condition associated with different etiologies, ranging from hormonal changes to chemotherapy, that affects over 80 million people in the USA. Nevertheless, there are currently few FDA-approved drugs for topical treatment, and existing formulations still present skin irritation issues, compromising treatment adherence. This work aimed to develop a safe formulation based on nanostructured lipid carriers (NLC) that entrap an association of minoxidil and latanoprost and target drug delivery to the hair follicles. To do so, thermal techniques combined with FTIR were used to assess the chemical compatibility of the proposed drug association. Then, NLC with 393.5 ± 36.0 nm (PdI<0.4) and +22.5 ± 0.2 mV zeta potential were produced and shown to entrap 86.9% of minoxidil and 99.9% of latanoprost efficiently. In vitro, the free drug combination was indicated to exert positive effects over human primary epidermal keratinocytes, supporting cell proliferation, migration and inducing the mRNA expression of MKI67 proliferation marker and VEGF - a possible effector for minoxidil-mediated hair growth. Interestingly, such a favorable drug combination profile was optimized when delivered using our NLC. Furthermore, according to the HET-CAM and reconstructed human epidermis assays, the nanoformulation was well tolerated. Finally, drug penetration was evaluated in vitro using porcine skin. Such experiments indicated that the NLC could be deposited preferentially into the hair follicles, causing a considerable increase in the penetration of the two drugs in such structures, compared to the control (composed of the free compounds) and generating a target-effect of approximately 50% for both drugs. In summary, present results suggest that hair follicle-targeted delivery of the minoxidil and latanoprost combination is a promising alternative to treat alopecia.

Topical and oral minoxidil for hair disorders in pediatric patients: What do we know so far?

Minoxidil is a strong arterial vasodilator, first introduced as an antihypertensive medication. In dermatology, topical minoxidil (TMX) has been used for many types of alopecia. TMX is not FDA-approved in patients under 18 years old and there are no guidelines for its pediatric use. Low-dose oral minoxidil (OMX) has been used off-label for hair loss treatment in adults expecting to achieve better therapeutic compliance and greater clinical efficacy. However, little is known about TMX and OMX in pediatric population. the literature presented on TMX and OMX in children to date was reviewed. The terms "minoxidil", "child", "children", "childhood", and "infant" were used to perform a literature search in MEDLINE through PubMed. The search was limited to articles about humans and available in English. While 25 relevant articles were selected, duplicate titles were excluded. This article pointed out the use of minoxidil in several pediatric hair diseases. Even when used topically, dermatologists should be aware of potential risks of systemic absorption. In particular situations, OMX in very low doses may be considered. To date, there are no guidelines regarding the ideal dose or minimum age for using the drug topically or systemically.

Minoxidil and its use in hair disorders: a review

Minoxidil was first introduced as an antihypertensive medication and the discovery of its common adverse event, hypertrichosis, led to the development of a topical formulation for promoting hair growth. To date, topical minoxidil is the mainstay treatment for androgenetic alopecia and is used as an off-label treatment for other hair loss conditions. Despite its widespread application, the exact mechanism of action of minoxidil is still not fully understood. In this article, we aim to review and update current information on the pharmacology, mechanism of action, clinical efficacy, and adverse events of topical minoxidil.