Abstract

Background: Androgenetic alopecia (AGA) is a complex condition that requires personalized topical treatments for effective management. By optimizing vehicle selection, we aim to contribute to enhanced treatment efficacy and patient compliance.
Objective: This study aimed to demonstrate the compatibility of three formulations used for AGA treatment with a ready-to-use Fagron Advanced Derma vehicle Espumil™.
Methods: The formulations were evaluated for their beyond-use dates at 30, 60, and 90 days. High-performance liquid Chromatography (HPLC) analyses were conducted to evaluate the following formulation concentrations in Espumil™: minoxidil 5.0% + caffeine 2.0, minoxidil 5.0% + 17-alpha-estradiol 0.05% and minoxidil 5.0% + tretinoin 0.1%.
Results: All three formulations presented beyond-use dates (BUD) over 90 days.
Conclusion: This study validates the compatibility of three API combinations from different pharmacological classes with Espumil™, aiming to extend the vehicle utility safely and effectively over longer periods. The findings suggest that this ready-to-use vehicle can be a viable option for personalized treatments whereby patient cosmetic preferences are considered, contributing to greater patient adherence in treating AGA.

Keywords:Androgenetic alopecia (AGA); Vehicles; Compatibility; Patient compliance; Compounding pharmacy; Personalized treatments

Introduction

Androgenetic alopecia (AGA) is one of the leading causes of hair loss, affecting at least 80% of men and 50% of women by the age of 70 [1]. AGA is characterized by receding frontal hairline in men and diffuse hair thinning in women due to the miniaturization of hair follicles.2 This follicular miniaturization is primarily driven by hormones, particularly dihydrotestosterone (DHT), which binds to the androgen receptors in hair follicles on the scalp [3]. Additionally, genetic predisposition has been recognized as a key factor in AGA’s pathogenesis [4].

Although the incidence of AGA is statistically prevalent, there are no universal guidelines for its treatment [2]. This is mainly due to the wide variety of causes among patients, presenting challenges for dermatologists globally to tailor a precise treatment approach. Currently, two FDA-approved drugs exist,including topical minoxidil and oral finasteride [3]. Beyond these, various off-label therapies have demonstrated efficacy, including topical treatments, hormonal therapies, and nutraceuticals [4]. Despite these available options, it has been reported that patient compliance is one of the most significant barriers to non-surgical interventions in AGA [5]. Patients often find topical treatments for AGA challenging due to several unfavourable characteristics such as difficulty in application, greasy textures, and the buildup of residue on the scalp, which can lead to discomfort and reluctance to use the treatment consistently [6,7].

These issues significantly reduce adherence to long-term therapy, ultimately affecting the effectiveness of the treatment. As a result, the choice of a dermatological vehicle becomes critical, as it directly impacts factors such as ease of application, reduction of greasiness and residue, and overall patient comfort, all of which play a key role in encouraging sustained use and improving therapeutic outcomes [8,9]. Thus, compounding a personalized treatment may integrate patient preferences, which may lead to increased patient compliance and more effective treatment outcomes. Thus, this study aimed to investigate personalized approaches in treating AGA by providing beyond-use dates (BUD) of formulations with demonstrated efficacy and their compatibility with ready-to-use vehicles that could potentially increase patient compliance. The formulations that were selected to be tested include minoxidil 5.0% + caffeine 2.0%, minoxidil 5.0% + 17-alpha-estradiol 0.05%, and minoxidil 5.0% + tretinoin 0.1%.

Materials and Methods

Reagents, Reference Standards, and Materials

Fagron supplied all the APIs, and the vehicle used in this study. Trione Ninhydrin Reagent, Na+ Eluent (pH 3.15; 4.25; 6.40), Na+ Column Regenerant were from LC Tech; sodium hydroxide 0.1 N, orthophosphoric acid 85% was from VWR; hydrochloric acid 0.1 N from Prolabo; acetonitrile, methanol and methyl tert-butyl ether were from Merck; acetic acid, chloroform and glycerol were from Sigma. Lastly, all volumetric glassware and the analytical balance used were calibrated. The concentrations of the three API-combinations as well as their pharmaceutical indications are listed in Table 1.

Equipment

High-Performance Liquid Chromatography (HPLC) analyses were performed on a qualified and calibrated chromatography system. This system was composed of a quaternary gradient pump (G1311B), degasser (G1322A) and the isopump (G1310B) from Agilent; a sonicator (FB15060) from Fisher Scientific; and an oven (ED115) from Binder.

Chromatographic Conditions

The chromatographic determinations were developed inhouse. The exact chromatographic conditions used for each API and API combinations are stated in Table 2. The columns were linked to a pre-column with the same packing (4.0 × 3.0 mm, 5μm) from the same vendor as the columns.

Validation of the HPLC Method

The HPLC methods mentioned in this study were validated following internal protocols aligned with the USP and the ICH guidelines [10,11]. To assess the specificity of each method, comparisons were made using HPLC analyses of a standard solution, a blank Espumil™ solution, and a blank solution of the mobile phase/diluents, both with and without the matrix. The acceptance criterion was the non-interference of extraneous peaks to the main peak of the API.

Preparation of the Creams

The samples containing the API combinations were prepared using the following standardized procedures:
Minoxidil 5.0% and caffeine 2.0% in Espumil™: First, the quantity of each ingredient required was calculated. Each ingredient was accurately weighed and/or measured. The caffeine and minoxidil were dissolved in approximately ¾ of the Espumil™ and with constant stirring, heated (>50°C) until a particulatefree solution was observed. Finally, the solution was filtered, and Espumil™ was added to reach the final volume. Minoxidil 5.0% and 17-alpha-estradiol 0.05% in Espumil™: The quantity of each ingredient required for the prescription was calculated. Each ingredient was accurately weighed and measured. The 17-alpha-estradiol was dissolved in Dimethyl sulfoxide (DMSO) (or Ethanol) using a mortar and pestle until a clear solution was observed. This preparation was poured into a beaker, and the mortar and pestle were rinsed with Espumil™, which was added to the solution. Approximately ¾ of the Espumil™ was added to the 17-alpha-estradiol solution, and minoxidil was incorporated under constant stirring (heated, if necessary, <50°C) until a clear solution was observed. The solution was filtered, and Espumil™ was added to reach the final volume. Minoxidil 5.0% and tretinoin 0.1% in Espumil™: The tretinoin was dissolved in ethanol, then minoxidil and approximately ¾ of the Espumil™ were added to a beaker. With constant stirring and heating (<50°C), the mixture was stirred until a particulate-free solution was observed. The solution was then filtered, and Espumil™ was added to reach the final volume.

Compatibility Study

The cream samples were assayed by HPLC at pre-determined time points to verify the compatibility of the API combinations with their respective vehicles (Table 1). The sampling times were 0 days (t = 0), 30 days (t = 30), 60 days (t = 60), and 90 days (t = 90). A visual inspection was performed to check for phase separation, sedimentation, and discoloration. All products were assayed six times, and the results were expressed as the mean from six independent measurements. For that purpose, samples were diluted, sonicated for 10 minutes, and then filtered in 15-mm regenerated cellulose syringe filters with 0.45-μm pore size before injection into the HPLC system. The evaluation parameter was the percent recovery with respect to t=0, using the HPLC method (results given as percentage).

Results & Discussion

Validation studies of all analytical methods were conducted, and the results in Table 3 met the respective acceptance criteria, confirming the methods’ suitability for the study’s objectives. Compatibility-indicating studies were performed to ensure the methods were fully validated and capable of identifying the decomposition of the API combinations through chromatographic analysis. Extraneous peaks were monitored to confirm the absence of late elution peaks, which could indicate impurities or degradation products.

At each sampling time, the visual appearance of the solutions was evaluated to verify their homogeneity and physical compatibility (data not shown). The study observed no phenomena, including sedimentation, discoloration, or phase separation, when the formulation content was within specifications. Table 4 presents the chemical compatibility results as a relative percentage of recovery, with the initial sampling time set at 100%. For the creams to be considered stable, the relative percentage recovery should remain within the range of 90% to 110%. This range ensures that the API combinations maintain their potency and effectiveness over the specified period, validating the compatibility of the formulations with the selected vehicles.

The choice of the dermatological vehicle is crucial when treating AGA [4]. In this study, we evaluated one vehicle, Espumil™ from the Fagron Advanced Derma (FAD) line, chosen for its compatibility with a range of formulations and its established safety profile. Importantly, all FAD vehicles are formulated based on the latest scientific insights, particularly for use on sensitive skin due to inflammatory conditions such as AGA. Also, the formulation of each vehicle is based on specific skin types (i.e., oily, dry, and sensitive scalp), and their gentle feel improves patient experience, potentially leading to increased compliance to long-term treatment.

Minoxidil, a widely used API for AGA treatment, was evaluated in this study alongside several API-combinations. Previous studies have indicated that the systemic absorption of topically applied minoxidil is largely influenced by the formulation vehicle [12]. Thus, in the current study we aimed to evaluate the compatibility of compounding minoxidil in a ready-to-use vehicle in combination with APIs from different pharmacological classes [12]. Espumil™ was the vehicle of choice, a lipophilic foam base with unique delivery features to ensure simple application of APIs on difficultto- treat areas, such as hairy skin and the scalp, making it an ideal base for treating AGA.

From our results, we found that minoxidil compounded with caffeine remained stable over 90 days in Espumil™, with the formulation retaining a slightly yellow and clear appearance. Additionally, minoxidil and 17-alpha-estradiol showed compatibility in Espumil™ over 90 days. To the best of our knowledge, no prior studies have examined the compatibility of 17-alpa-estradiol in topical formulations, and our findings contribute to the limited research on its dermatological applications. Similarly, the combination of minoxidil and tretinoin demonstrated compatibility over 90 days, supporting its longterm effectiveness. These findings align with those of Zhargi and their colleagues, demonstrating the inherent compatibility of the minoxidil-tretinoin combination [13].

Conclusion

This compatibility study aimed to demonstrate the effectiveness of Espumil™, a Fagron Advanced Derma vehicle. Given the diverse pathological causes of AGA, treatment approaches often vary significantly among patients. However, one consistent challenge across all treatments is ensuring long-term patient compliance. Therefore, utilizing cosmetically acceptable formulations personalized to the patient’s preferences may contribute to greater treatment outcomes. Our testing aimed to provide evidence-based support to patient-centred and personalized therapeutic solutions.

We have tested three formulations using Espumil™ and found the following beyond-use dates (BUD):
• Minoxidil 5.0% and caffeine 2.0% = BUD 90 days.
• Minoxidil 5.0% and 17-alpha-estradiol 0.05% = BUD 90 days.
• Minoxidil 5.0% and tretinoin 0.1% = BUD 90 days.

All formulations presented a beyond-use date of 90 days. This study contributes to the growing body of research on topical AGA treatments and offers valuable scientific evidence for personalized treatment strategies using Fagron Advanced Derma vehicles.

1. Yuan AR, Bia Q, Gao JQ (2020) Current advances in stem cell-based therapies for hair regeneration. Eur J Pharmacol 881:173197.
2. U Blume-Peytavi, A Blumeyer, A Tosti, A Finner, V Marmol, et al. (2011) S1 guideline for diagnostic evaluation in androgenetic alopecia in men, women and adolescents. British Journal of Dermatology 164(1): 5-15.
3. Devjani S, Ezemma O, Kelley KJ, Stratton E, Senna M (2023) Androgenetic Alopecia: Therapy Update. Drugs 83(7): 701-715.
4. Nestor MS, Ablon G, Gad, A, Han H, Fischer DL (2021) Treatment options for androgenetic alopecia: Efficacy, side effects, compliance, financial considerations, and ethics. J Cosmet Dermatol 20(12): 3759-3781.
5. Shadi Z (2023) Compliance with Topical Minoxidil and Reasons for Discontinuation among Patients with Androgenetic Alopecia. Dermatol Ther (Heidelb) 13: 1157-1169.
6. Shadi Z (2023) Compliance to Topical Minoxidil and Reasons for Discontinuation among Patients with Androgenetic Alopecia. Dermatol Ther (Heidelb) 13(5): 1157-1169.
7. Nestor MS, Ablon G, Gade A, Han H, Fischer DL (2021) Treatment options for androgenetic alopecia: Efficacy, side effects, compliance, financial considerations, and ethics. J Cosmet Dermatol 20(12): 3759-3781.
8. Mathias Tiedemann Svendsen, Steven R Feldman, Mathias Tiedemann Svendsen, Steven R Feldman, Andersen KE, et al (2021) Psoriasis patient preferences for topical drugs: a systematic review. Journal of Dermatological Treatment 32(5): 478-483.
9. Barnes TM, Mijaljica D, Townley JP, Spada F, Harrison IP (2021) Vehicles for Drug Delivery and Cosmetic Moisturizers: Review and Comparison. Pharmaceutics 13(12): 2012.
10. Aukerman EL, Jafferany M (2023) The psychological consequences of androgenetic alopecia: A systematic review. J Cosmet Dermatol 22(1): 89-95.
11. Guy RC (2014) International Conference on Harmonisation. Encyclopedia of Toxicology: Third Edition 1070-1072.
12. Shreya Singh, Anant Patil, Nika Kianfar, Anna Waśkiel-Burnat, Lidia Rudnicka, et al. (2022) Does topical minoxidil at concentrations higher than 5% provide additional clinical benefit? Clin Exp Dermatol 47(11): 1951-1955.
13. Zarghi A, Jenabi M, Ebrahimian AJ (1998) HPLC determination of the stability of tretinoin in tretinoin–minoxidil solution. Pharm Acta Helv 73(3): 163-165.