A Clinician's Guide to Topical Retinoids

Role of vitamin D supplement adjunct to topical benzoyl peroxide in acne: a randomized double-blinded controlled study

Background

Acne is an inflammatory condition of the pilosebaceous unit. Previous studies have established a link between acne and vitamin D deficiency and the potential effectiveness of vitamin D supplementation in treatment. However, the efficacy of vitamin D as an adjuvant treatment for acne remains unknown.

Objective

To evaluate the efficacy of weekly vitamin D2 oral administration as an adjunctive treatment to standard topical care for acne.

Methods

This study was a randomized, double-blind, placebo-controlled trial including subjects with mild-to-moderate acne. Topical 2.5% benzoyl peroxide was applied twice daily for 12 weeks to all subjects. Subjects were randomly allocated to receive either oral vitamin D2 40,000 IU weekly or placebo weekly during the treatment period. No additional treatment was administered during the 4-week follow-up period.

Results

A total of 44 subjects were included in this study. All of them had inadequate 25(OH)D levels. Both regimens showed significant improvement in acne during the treatment period. Weekly vitamin D2 supplementation significantly prevented the relapse of inflammatory acne lesions (P = .048) at the follow-up visit. No adverse effects or biochemical changes were observed.

Limitations

There were no subjects of severe acne vulgaris.

Conclusion

Adjunctive weekly vitamin D2 supplementation to standard topical benzoyl peroxide could reduce relapses of inflammatory lesions in mild-to-moderate acne.

Keratosis pilaris treatment paradigms: assessing effectiveness across modalities

This review aims to present a comprehensive synthesis of the existing treatment modalities for keratosis pilaris (KP) and evaluate their therapeutic efficacy. KP is a prevalent chronic dermatological condition typified by its unique 'chicken skin appearance', with the cheeks being the most commonly involved sites. Numerous therapeutic interventions have emerged, given its substantial prevalence and impact on skin aesthetics and psychological wellbeing. Nonetheless, a consistent therapeutic response has been challenging to achieve. This review endeavours to collate and critically appraise the current treatment landscape for KP. An exhaustive literature search was performed using databases such as Ovid, PubMed and Scopus. From an initial count of 459 articles identified after deduplication, 52 were selected for inclusion after a thorough full-text examination for articles with concrete outcome data highlighting the efficacies of different therapeutic modalities; articles that lacked data or were tangential to the core focus on KP treatment were excluded. The included articles were then catalogued based on the nature of treatment strategies and their respective outcomes. Among the various therapeutic interventions, laser and light modalities appear to be supported by the most substantial evidence base. Notably, the Nd:YAG (neodymium-doped yttrium-aluminium-garnet) laser, attributed to its longer wavelength, emerged as a preferred option. While other therapeutic avenues have also exhibited notable improvements in skin texture and discolouration relative to baseline, the inconsistency in outcome measures underscores the need for a standardized, KP-specific scoring system to foster a more coherent comparison across treatments. Based on the current evidence, Nd:YAG laser therapy demonstrates promising effectiveness with a relatively favourable side-effect profile. However, the landscape of KP treatment is multifaceted, and further studies are essential to solidify recommendations.

A Comprehensive Review of the Strategies to Reduce Retinoid-Induced Skin Irritation in Topical Formulation

Currently, retinoids are known for their abundant benefits to skin health, ranging from reducing signs of aging and decreasing hyperpigmentation to treating acne. However, it cannot be denied that there are various side effects associated with the use of retinoids on the skin, one of which is irritation. Several approaches can be employed to minimize the irritation caused by retinoids. This review article discusses topical retinoid formulation technology strategies to reduce skin irritation effects. The methodology used in this study is a literature review of 21 reference journals. The sources used in compiling this review are from PubMed, Scopus, ScienceDirect, and MEDLINE. The findings obtained indicate that the following methods can be used to lessen retinoid-induced irritation in topical formulations: developing drug delivery systems in the formulation, such as encapsulating retinoids, transforming retinoids into nanoparticles, forming complexes (e.g., with cyclodextrin), and binding retinoids with carriers (e.g., polymers, NLC, SLN), adding ingredients with anti-irritation activity, skin barrier improvement, and increased skin hydration to retinoid formulations (e.g., combinations of glucosamine, trehalose, ectoine, sucralfate, omega-9, and 4-t-butylcyclohexanol, addition of ethanolic bark extract of Alstonia scholaris R. Br).

Exploring Acne Treatments: From Pathophysiological Mechanisms to Emerging Therapies

Acne vulgaris is a common dermatological condition that can present across different ages but predominantly affects adolescents and young adults. Characterized by various lesion types, the pathogenesis of acne is complex, involving genetic, hormonal, microbial, and inflammatory factors. This review comprehensively addresses current and emerging acne management strategies, emphasizing both topical and systemic treatments, procedural therapies, and dietary modifications. Key topical agents include retinoids, benzoyl peroxide, antibiotics, and other specialized compounds. Systemic options like antibiotics, hormonal therapies, and retinoids offer significant therapeutic benefits, particularly for moderate to severe cases. Procedural treatments such as laser devices, photodynamic therapy, chemical peels, and intralesional injections present viable alternatives for reducing acne symptoms and scarring. Emerging therapies focus on novel biologics, bacteriophages, probiotics, and peptides, providing promising future options. This review underscores the importance of personalized approaches to treatment due to the multifaceted nature of acne, highlighting the potential of innovative therapies for improving patient outcomes.

Structure-Activity Relationships and Therapeutic Applications of Retinoids in View of Potential Benefits from Drug Repurposing Process

Vitamin A, an essential micronutrient, is integral to various biological processes crucial for organismal development and maintenance. Dietary sources of vitamin A encompass preformed retinol, retinyl esters, and provitamin A carotenoids. Retinoic acid (RA), a key component, plays pivotal roles in vision, cell proliferation, apoptosis, immune function, and gene regulation. Drug repurposing, an effective strategy for identifying new therapeutic applications for existing drugs, has gained prominence in recent years. This review seeks to provide a comprehensive overview of the current research landscape surrounding retinoids and drug repurposing. The scope of this review encompasses a comprehensive examination of retinoids and their potential for repurposing in various therapeutic contexts. Despite their efficacy in treating dermatological conditions, concerns about toxicity persist, driving the search for safer and more potent retinoids. The molecular mechanisms underlying retinoid activity involve binding to retinoic acid receptors (RARs) and retinoid X receptors (RXRs), leading to transcriptional regulation of target genes. This review seeks to shed light on the possibilities for repurposing retinoids to cover a wider spectrum of therapeutic uses by exploring recent scientific progress. It also aims to offer a more comprehensive understanding of the therapeutic prospects of retinoids and the broader impact of drug repositioning in contemporary medicine.

Life at the interface: Engineering bio-nanomaterials through interfacial molecular self-assembly

Interfacial self-assembly describes the directed organization of molecules and colloids at phase boundaries. Believed to be fundamental to the inception of primordial life, interfacial assembly is exploited by a myriad of eukaryotic and prokaryotic organisms to execute physiologic activities and maintain homeostasis. Inspired by these natural systems, chemists, engineers, and materials scientists have sought to harness the thermodynamic equilibria at phase boundaries to create multi-dimensional, highly ordered, and functional nanomaterials. Recent advances in our understanding of the biophysical principles guiding molecular assembly at gas-solid, gas-liquid, solid-liquid, and liquid-liquid interphases have enhanced the rational design of functional bio-nanomaterials, particularly in the fields of biosensing, bioimaging and biotherapy. Continued development of non-canonical building blocks, paired with deeper mechanistic insights into interphase self-assembly, holds promise to yield next generation interfacial bio-nanomaterials with unique, and perhaps yet unrealized, properties. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Topical and Systemic Retinoids in the Management of Hidradenitis Suppurativa: A Comprehensive Literature Review

Hidradenitis suppurativa (HS) is a debilitating chronic skin disorder characterized by painful inflammatory nodules, abscesses and sinus tracts involving intertriginous areas and has an adverse impact on patient quality of life. Over the past decade, the therapeutic options of HS have increased significantly to comprise multiple modalities, including topical medication, systemic therapies (mainly antibiotics, retinoids, and biologics), surgical approaches, and lifestyle modifications. Biologics alone or in combination with surgery remain the treatment of choice for moderate to severe disease. However, non-biologic therapies (including retinoids) may be used as monotherapy for mild disease and in combination with biologics and surgical treatment in moderate to severe disease. Retinoids, specifically isotretinoin, acitretin, and alitretinoin, are historically used in the management of HS, supported by anecdotal evidence and with variable treatment response. Although the current American and European guidelines offer different recommendations on the use of retinoids in HS, retinoids remain a valuable ally in HS management. This review provides a comprehensive analysis of the current scientific literature on retinoid therapy (topical and systemic) in HS, highlighting disparities in mechanisms of action, efficacy, and safety to clarify their role in HS treatment.

Attempts to Improve Lipophilic Drugs' Solubility and Bioavailability: A Focus on Fenretinide

The development of numerous drugs is often arrested at clinical testing stages, due to their unfavorable biopharmaceutical characteristics. It is the case of fenretinide (4-HPR), a second-generation retinoid, that demonstrated promising in vitro cytotoxic activity against several cancer cell lines. Unfortunately, response rates in early clinical trials with 4-HPR did not confirm the in vitro findings, mainly due to the low bioavailability of the oral capsular formulation that was initially developed. Capsular 4-HPR provided variable and insufficient drug plasma levels attributable to the high hepatic first-pass effect and poor drug water solubility. To improve 4-HPR bioavailability, several approaches have been put forward and tested in preclinical and early-phase clinical trials, demonstrating generally improved plasma levels and minimal systemic toxicities, but also modest antitumor efficacy. The challenge is thus currently still far from being met. To redirect the diminished interest of pharmaceutical companies toward 4-HPR and promote its further clinical development, this manuscript reviewed the attempts made so far by researchers to enhance 4-HPR bioavailability. A comparison of the available data was performed, and future directions were proposed.

Overview of popular cosmeceuticals in dermatology

The eternal pursuit to prevent ageing and maintain a youthful appearance has resulted in a rapidly expanding cosmeceutical industry. Cosmeceutical products, particularly of natural origin, are in high demand due to claims of efficacy for signs of ageing and other skin conditions. Consumers often include cosmeceutical products in their skin care regime as they are readily available, and a more affordable option compared to prescription products. However, many cosmeceutical ingredients lack clinical evidence regarding their efficacy and safety as these products are not regulated by the U.S. Food and Drug Administration. This review provides a brief overview of several popular cosmeceutical ingredients with regards to their potential indications, targets and mechanisms of action.

An Overview of Contemporary and Future Therapeutic Strategies for Scalp Psoriasis

Scalp psoriasis is a common manifestation of psoriasis that significantly impacts a patient's quality of life. About 80% of cases of psoriasis involve the scalp, making it the most frequently affected area of the body. The treatment of scalp psoriasis is particularly crucial because of its hard-to-treat nature and substantial adverse impacts on overall well-being. Along with the physical symptoms of discomfort and itching, psoriasis, especially when it affects the scalp, can cause severe psychological damage. Treating scalp psoriasis can be challenging due to its location and associated symptoms, such as scaling and pruritus, which is why various drugs have become widely used for refractory cases. Topical treatments like corticosteroids and vitamin D analogs manage scalp psoriasis by reducing inflammation and regulating skin cell growth. Tar-based shampoos, salicylic acid solutions, and moisturizers control scaling. Phototherapy with UVB light reduces inflammation. Severe cases may require systemic medications such as oral retinoids and immunosuppressants. While various therapies are accessible for scalp psoriasis, concerns arise due to their limited advantages and the absence of controlled studies assessing their effectiveness. Considering these challenges, there is a clear demand for innovative approaches to address this condition effectively. Recent advancements in topical therapies, phototherapy, systemic agents, and complementary therapies have shown promising results in managing scalp psoriasis. Also, the advent of biologics, specifically anti-IL-17 and anti-IL-23 drugs for scalp psoriasis, has seen significant improvements. The review highlights the lack of well-tolerated and effective treatments for scalp psoriasis and underscores the importance of further research in this area. The objective of this review is to clarify the different treatment options currently available or being investigated in clinical trials for managing scalp psoriasis.

Advances in the treatment of autosomal recessive congenital ichthyosis, a look towards the repositioning of drugs

Autosomal recessive congenital ichthyoses (ARCI) are a skin pathology due to genetic causes characterized by a variable degree of desquamation, accompanied by erythema. The degree of symptoms is variable, different altered genes are involved, and the symptoms drastically affect patients' quality of life. Topical treatments are a first-choice strategy due to their ease of application and cost; however, enteral administration of retinoids offers greater efficacy, although with certain limitations. Despite the treatment alternatives, ARCI will persist throughout life, disabling people. Therefore, the search for new treatments always remains necessary. Especially repositioning drugs could be a short-term alternative to new affordable treatments for patients. Taking advantage of extensive knowledge of known drugs or biologics could ensure more accessible and possibly lower-cost treatments. This review briefly and concisely addresses possible repositioning strategies with drugs and biologics for ichthyosis.

Does isotretinoin affect spermatogenesis in the long term? A rat model

OBJECTIVES

Spermatogenesis, in which cell regeneration continues, can be affected by environmental, chemical, psychological factors or various diseases. There is conflicting information in the literature about the effect of isotretinoin, which is widely used in acne treatment, on testes and spermatogenesis. Therefore, we planned a rat study to evaluate the long-term efficacy of oral isotretinoin on testicular tissues and spermatogenesis.

MATERIALS AND METHODS

The Group 1 (n = 6) 7.5 mg/kg/day and the Group 2 (n = 6) received isotretinoin at a dose of 30 mg/kg/day dissolved in sunflower oil, the Sham Group (n = 6) received only sunflower oil by gavage, and the control group (n = 6) received standard feed and water for four weeks. After the 4th week, all animals were fed with standard feed and water and followed for the next four weeks. At the end of the 8th week, all animals were sacrificed under deep anesthesia. Seminiferous tubule diameters, epithelial thickness, apoptotic index, sperm number and motility recorded Results: Sperm count, motility, vitality, diameter of seminiferous tubule and germinal epithelium thickness were decreased and apoptotic index increased in the groups received isotretinoin. There was no significant difference between the groups in terms of testosterone levels.

CONCLUSIONS

We consider that further comprehensive studies, including human clinical trials, should be conducted to examine the negative effects of isotretinoin on spermatogenesis in the long term especially when there is a need using isotretinoin in men for various reasons and to eliminate the contradictions in the literature in this regard.

Comparative Efficacy of Pharmacological Treatments for Acne Vulgaris: A Network Meta-Analysis of 221 Randomized Controlled Trials

PURPOSE

Acne is an extremely common skin disease with an estimated global prevalence of 9.4%. We aim to provide comprehensive comparisons of the common pharmacological treatments for acne.

METHODS

Randomized controlled trials comparing the efficacy of pharmacological therapies for acne vulgaris in patients of any age and sex and with a treatment duration of >2 weeks were included. PubMed and Embase databases were searched from inception until February 2022. Our prespecified primary end points were mean percentage reduction in total, inflammatory, and noninflammatory lesions. Treatment ranking was determined by P values.

RESULTS

There were 210 articles describing 221 trials and 37 interventions included in the analysis. Our primary analysis of percentage reduction in total lesion count had 65,601 patients enrolled. Across all trials, the mean age was 20.4 years. The median duration of treatment was 12 weeks. The median total, inflammatory, and noninflammatory lesion counts were 72, 27, and 44, respectively. The most effective treatment was oral isotretinoin (mean difference [MD] = 48.41; P = 1.00), followed by triple therapy containing a topical antibiotic, a topical retinoid, and benzoyl peroxide (BPO) (MD = 38.15; P = .95) and by triple therapy containing an oral antibiotic, a topical retinoid, and BPO (MD = 34.83; P = .90). For monotherapies, oral or topical antibiotics or topical retinoids have comparable efficacy for inflammatory lesions, while oral or topical antibiotics have less effect on noninflammatory lesions.

CONCLUSION

The most effective treatment for acne is oral isotretinoin, followed by triple therapies containing a topical retinoid, BPO, and an antibiotic. We present detailed comparisons of each intervention to serve as a practical database.

TFOS Lifestyle: Impact of cosmetics on the ocular surface

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

Polymeric Nanoparticles as Tunable Nanocarriers for Targeted Delivery of Drugs to Skin Tissues for Treatment of Topical Skin Diseases

The topical route is the most appropriate route for the targeted delivery of drugs to skin tissues for the treatment of local skin diseases; however, the stratum corneum (SC), the foremost layer of the skin, acts as a major barrier. Numerous passive and active drug delivery techniques have been exploited to overcome this barrier; however, these modalities are associated with several detrimental effects which restrict their clinical applicability. Alternatively, nanotechnology-aided interventions have been extensively investigated for the topical administration of a wide range of therapeutics. In this review, we have mainly focused on the biopharmaceutical significance of polymeric nanoparticles (PNPs) (made from natural polymers) for the treatment of various topical skin diseases such as psoriasis, atopic dermatitis (AD), skin infection, skin cancer, acute-to-chronic wounds, and acne. The encapsulation of drug(s) into the inner core or adsorption onto the shell of PNPs has shown a marked improvement in their physicochemical properties, avoiding premature degradation and controlling the release kinetics, permeation through the SC, and retention in the skin layers. Furthermore, functionalization techniques such as PEGylation, conjugation with targeting ligand, and pH/thermo-responsiveness have shown further success in optimizing the therapeutic efficacy of PNPs for the treatment of skin diseases. Despite enormous progress in the development of PNPs, their clinical translation is still lacking, which could be a potential future perspective for researchers working in this field.

Efficacy of the continuous use of a lotion with carbon dioxide on male subjects with mild acne

OBJECTIVE

Acne vulgaris is caused by dyslipidemia, dyskeratosis and/or abnormal bacterial growth. The obstruction of skin pores due to hyperkeratosis of the infundibulum contributes to the formation of comedones. Thus, normalizing keratinization of epidermal cells in skin pores might be useful to improve acne. Recently, it has been found that the transcutaneous application of carbon dioxide (CO₂ ) regulates imbalances of the desquamatory process. In this study, we evaluated the efficacy of a skin lotion containing CO₂ on mild acne.

METHODS

Twenty-four healthy Japanese males (20-29 years old) with mild acne attended this evaluation. The subjects were divided into 2 groups, one group used a skin lotion containing CO₂ and the other group used a skin lotion without CO₂ . Following facial washing, each subject topically applied the skin lotion with or without CO₂ twice a day for 4 weeks. Prior to the start of the evaluation (week 0) and following 2 and 4 weeks of treatment, acne symptoms were assessed by a dermatologist and by instrumental measurements.

RESULTS

Topical application of the skin lotion with CO₂ for 4 weeks significantly improved acne symptoms, which was recognized by the subjects. However, treatment with the skin lotion without CO₂ did not improve acne symptoms. This improvement of acne symptoms by CO₂ was not accompanied by changes in sebum levels, skin surface pH, skin capacitance, or porphyrin levels.

CONCLUSION

The transcutaneous application of a lotion with CO₂ improves acne symptoms by normalizing keratinization without affecting skin surface conditions.

Use of Retinoids in Topical Antiaging Treatments: A Focused Review of Clinical Evidence for Conventional and Nanoformulations

Nowadays, numerous skincare routines are used to rejuvenate aging skin. Retinoids are one of the most popular ingredients used in antiaging treatments. Among the representatives of retinoids, tretinoin is considered the most effective agent with proven antiaging effects on the skin and can be found in formulations approved as medicines for topical treatment of acne, facial wrinkles, and hyperpigmentation. Other retinoids present in topical medicines are used for various indications, but only tazarotene is also approved as adjunctive agent for treatment of facial fine wrinkling and pigmentation. The most commonly used retinoids such as retinol, retinaldehyde, and retinyl palmitate are contained in cosmeceuticals regulated as cosmetics. Since clinical efficacy studies are not required for marketing cosmetic formulations, there are concerns about the efficacy of these retinoids. From a formulation perspective, retinoids pose a challenge to researchers as a result of their proven instability, low penetration, and potential for skin irritation. Therefore, novel delivery systems based on nanotechnology are being developed to overcome the limitations of conventional formulations and improve user compliance. In this review, the clinical evidence for retinoids in conventional and nanoformulations for topical antiaging treatments was evaluated. In addition, an overview of the comparison clinical trials between tretinoin and other retinoids is presented. In general, there is a lack of evidence from properly designed clinical trials to support the claimed efficacy of the most commonly used retinoids as antiaging agents in cosmeceuticals. Of the other retinoids contained in medicines, tazarotene and adapalene have clinically evaluated antiaging effects compared to tretinoin and may be considered as potential alternatives for antiaging treatments. The promising potential of retinoid nanoformulations requires a more comprehensive evaluation with additional studies to support the preliminary findings.