Clinical efficacy and safety of a topical combination of retinaldehyde 0.1% with erythromycin 4% in acne vulgaris

A pilot study evaluating the efficacy and safety of retinaldehyde-loaded niosomes against mild-to-moderate acne

BACKGROUND

Retinoids are the mainstay of topical therapy for acne. To improve the efficacy and minimize the side effects of retinoids, various novel drug delivery mechanisms, including nanoparticles, have been developed.

AIM

To evaluate the efficacy and safety of a retinaldehyde-loaded niosome (RA-N) nanoemulsion against sebum secretion and keratinization on mild-to-moderate acne.

PATIENTS/METHODS

Twenty-three participants exhibiting mild-to-moderate acne with both closed and open comedones were included. They applied a 0.05% RA-N nanoemulsion daily for 4 weeks, did not to use any other emollient or topical pharmaceutical, and were asked to report any symptoms and treatment satisfaction.

RESULTS

The participants demonstrated significantly fewer closed and open comedones after 2 and 4 weeks of treatment than at baseline (*p < 0.05). The mean sebum secretion, measured using Sebumeter®, was 327.95 ± 90.20 μg cm^-2 at baseline and reduced to 282.60 ± 99.70 and 250.65 ± 97.6 μg cm^-2 , respectively, after 2 and 4 weeks of treatment (*p < 0.05). The mean desquamation index, determined using Visioscan®, was 10.99 ± 1.69 at baseline and decreased to 9.81 ± 1.10 and 8.89 ± 1.32, respectively, after 2 and 4 weeks of treatment (*p < 0.05). The application of the RA-N nanoemulsion resulted in a significantly lower desquamation level, suggesting that the RA-N nanoemulsion was well-tolerated without any skin irritation. None of the participants reported a serious adverse event during this study.

CONCLUSION

Our findings suggest that the RA-N nanoemulsion was effective in improving comedones in acne-prone skin and safe for long-term application. Further studies are necessary to investigate the long-term effects of the application of the RA-N nanoemulsion in participants with inflammatory acne and acne scars.

The role of topical dermocosmetics in acne vulgaris

Acne is a common chronic inflammatory disease and treatment modalities based on acne severity are well established. The role of dermocosmetics in dermatology, and in particular acne, is becoming more important as more research elucidates the mechanisms of action of products in the pathogenesis of acne. Dermocosmetics have the potential to be used as monotherapy or in combination with medical treatment. Therefore, it has become important for dermatologists to understand dermocosmetics to effectively and appropriately advise patients on their use. The objective of this review was to provide new insights into the role of traditional and novel ingredients in dermocosmetics for the treatment of acne, based on the authors' objective assessment of the published literature. The type of products discussed include: those which have a sebostatic effect, such as topical antioxidants and niacinamide; agents targeting abnormal keratinization, such as salicylic acid, lipo-hydroxy acid, alpha-hydroxy acids, retinol-based products and linoleic acid; agents targeting Propionibacterium acnes, such as lauric acid; and anti-inflammatory agents such as nicotinamide, alpha-linolenic acid and zinc salts. Despite the scientific advances in understanding these cosmetic ingredients, there still remains a lack of rigorous controlled studies in this area.

Topical retinoids in acne vulgaris: update on efficacy and safety

Topical retinoids represent a mainstay of acne treatment because they expel mature comedones, reduce microcomedone formation, and exert anti-inflammatory effects. The first-generation retinoid tretinoin (all-trans retinoic acid) and the synthetic third-generation polyaromatics adapalene and tazarotene are approved for acne treatment by the US FDA, whereas topical tretinoin, isotretinoin (13-cis retinoic acid), and adapalene are accredited in Canada and Europe. Topical retinoids have a favorable safety profile distinct from the toxicity of their systemic counterparts. Local adverse effects, including erythema, dryness, itching, and stinging, occur frequently during the early treatment phase. Their impact varies with the vehicle formation, skin type, frequency and mode of application, use of moisturizers, and environmental factors such as sun exposure or temperature. The broad anti-acne activity and safety profile of topical retinoids justifies their use as first-line treatment in most types of non-inflammatory and inflammatory acne. They are also suitable as long-term medications, with no risk of inducing bacterial resistance, for maintenance of remission after cessation of initial combination therapy.

Topical retinoids in acne--an evidence-based overview

Topical retinoids are important tools in the management of acne because they act against comedones and microcomedones and have direct anti-inflammatory effects. The substances approved for acne treatment comprise tretinoin (all-trans-retinoic acid), isotretinoin (13-cis retinoic acid) as well as the synthetic third-generation polyaromatic retinoids adapalene and tazarotene, the latter being approved for acne treatment in the US only. Retinaldehyde is used in cosmetic preparations against acne. All topical retinoids are effective as single agents in mild to moderate acne but differ in efficacy and tolerability. Tazarotene 0.1% is more effective than tretinoin 0.025% or 0.1% microsphere gel or adapalene 0.1% gel or cream (EBM-level 2c). Adapalene 0.1% is equally effective to tretinoin 0.025% or tretinoin microsphere 0.1% gel or tretinoin 0.05% cream or isotretinoin 0.05% gel (EBM-level 2c). Adapalene 0.1% gel is significantly better tolerated than tazarotene 0.1% gel, tretinoin 0.025% and tretinoin 0.05% gel, tretinoin 0.05% cream, tretinoin microsphere 0.1% gel or isotretinoin 0.05% gel (EBM-level 2c). The safety profile of topical retinoids differs from their systemic counterparts and is related mainly to local adverse effects, such as erythema, dryness, itching and stinging. The currently available evidence justifies the use of topical retinoids in most types of acne and during maintenance treatment.

Combined 0.1% Retinaldehyde/ 6% Glycolic Acid Cream in Prophylaxis and Treatment of Acne Scarring

BACKGROUND

Acne often results in permanent, badly tolerated, difficult to treat scars.

OBJECTIVE

To evaluate the efficacy and safety of a 0.1% retinaldehyde/6% glycolic acid (RALGA) cream at preventing and treating acne scarring in patients previously treated for moderate acne.

METHODS

A double-blind vehicle-controlled study was conducted in 145 patients randomized to apply RALGAor vehicle cream every evening for 3 months. Global scarring score and patient's assessment of global efficacy, then residual acne lesions, quality of life and tolerance were evaluated at inclusion and each month until study completion.

RESULTS

Global scarring score, number of inflammatory lesions and comedones significantly improved in each group from day 28 (p<0.0001). Number of inflammatory lesions were significantly decreased only in the RALGA group. RALGA cream was more efficient than vehicle on scarring after 3 months in compliant patients (p=0.007) due to erythema and hyperpigmentation improvement.

CONCLUSION

RALGA cream is efficient at preventing and treating acne scarring in patients with moderate acne.

Treatment of acne with topical antibiotics: lessons from clinical studies

BACKGROUND

Over the past 20 years, major concerns have been repeatedly expressed over antibiotic-resistant acne in Europe and in the U.S.A. However, the clinical significance of these resistance patterns is poorly defined so that topical antibiotics remain one of the cornerstones of acne management.

OBJECTIVES

To determine whether we are facing decreased efficacy of topical formulations of erythromycin and clindamycin in clinical trials of therapeutic interventions for acne.

METHODS

To review systematically the results of the clinical trials investigating topical formulations of erythromycin and clindamycin for the treatment of inflammatory acne and to establish whether or not there is a decrease in the efficacy of these topical antibiotic formulations since their widespread introduction in the mid 1970s.

RESULTS

Of the 50 eligible controlled trials identified using a systematic electronic database search strategy, 45 (90%) incorporated a lesion count, making comparison across trials possible. Analysis of clinical studies investigating the effect of topical erythromycin in acne patients indicates a significant decrease in the effect of this antibiotic on inflammatory and noninflammatory lesion count over time (r = -2.140, P = 0.001 and r = -2.032, P = 0.001, respectively). Efficacy of topical clindamycin remained stable during the study period.

CONCLUSIONS

There is a gradual decrease in the efficacy of topical erythromycin in clinical trials of therapeutic intervention for acne, which is probably related to the development of antibiotic-resistant propionibacteria.

Pharmacology of RALGA, a Mixture of Retinaldehyde and Glycolic Acid

BACKGROUND

Retinoids and alpha-hydroxy acids (AHAs) are major compounds in topical therapy. They exert distinct but potentially complementary activities. However, their association is limited by their respective irritating potential. Recently, the first association between a retinoid and an AHA has been achieved; this formulation (RALGA) associates retinaldehyde (RAL)--a precursor of retinoic acid (RA)--and glycolic acid (GA)--an AHA.

OBJECTIVE

To study the pharmacological properties of RALGA.

METHODS

The bioavailability of RAL into the skin after topical RALGA was studied by HPLC, and its bioconversion to RA was analysed by measuring the enzyme activity of retinaldehyde dehydrogenase and the RA content in the epidermis and dermis. The retinoid activity of RALGA was studied on the modulation of Hhb4 keratin mRNA on the tail of C57BL/6 mice, and its comedolytic properties on the size and density of dermal cysts and the morphology of sebaceous glands in hairless mice.

RESULTS

Epidermal and dermal concentrations of RAL and RA were higher after RALGA treatment, as compared to both RAL 0.1% alone and RA 0.05% alone; this indicates that the presence of GA favours the bioavailability and biotransformation of RAL into RA. The retinoid activity of RALGA (suppression of Hhb4 mRNA keratin) was similar to that of RAL alone, indicating that the presence of GA does not interfere with specific retinoid activity; GA alone had no effect in this test, which confirms the specificity of Hhb4 mRNA keratin modulation for retinoid activity. The diameter and the density of dermal cysts as well as the size of sebaceous glands were significantly decreased by RALGA.

CONCLUSION

These observations indicate that the addition of an AHA such as GA to a retinoid such as RAL results in a better bioavailability of the retinoid, thus a higher delivery of RA, which potentiates the biological activities of the retinoid. This combination allows a delivery of high amounts of RA in the skin while preventing the side-effects usually observed with high concentrations of topical RA.

RALGA (Diacnéal®), a Retinaldehyde and Glycolic Acid Association and Postinflammatory Hyperpigmentation in Acne – A Review

Acne vulgaris affects 3 out of 4 adolescents and usually vanishes at the end of puberty with either no sequelae or mild to moderate sequelae, such as postinflammatory hyperpigmenation (PIH), which may result in psychological and emotional damages. The poor tolerability of the actual treatments (secondary inflammation) is a hindrance to therapy. Retinaldehyde (RAL), a precursor of retinoic acid, has shown depigmenting activity. Glycolic acid (GA) decreases the excess of pigment by a wounding and re-epithelization process. Thus, a synergistic effect was expected from the combination of RAL 0.1% and GA 6% RALGA (Diacneal) in the treatment of acne vulgaris and PIH. Efficacy results of preclinical and clinical trials tend to confirm the expectations for both acne and PIH treatment. A good tolerability was observed. In conclusion, the cosmetic cream Diacneal is a well-tolerated treatment for the prevention and healing of PIH in acne patients.

Efficacy and Safety of 0.1% Retinaldehyde/ 6% Glycolic Acid (Diacnéal®) for Mild to Moderate Acne vulgaris

BACKGROUND

Retinaldehyde and glycolic acid are both efficient in acne.

OBJECTIVE

To evaluate the efficacy and tolerability of a 0.1% retinaldehyde/6% glycolic acid combination (Diacneal) for mild to moderate acne vulgaris.

METHODS

Overall physician and patient ratings of acne symptom severity and tolerance were performed at baseline, months 1, 2 and 3.

RESULTS

Mean numbers of papules, pustules and comedones were significantly reduced from month 1 onwards. A significant advantage of Diacneal over vehicle was demonstrated on the percentages of patients with ongoing healing lesions at month 2, healing ancient lesions from month 1 and patients with 'important/very important' global improvement from month 2 (50.0 vs. 26.3%) confirmed by patients at month 3 (86.1 vs. 58.8%). Products were well tolerated; only 1 patient had to stop the treatment.

CONCLUSIONS

Diacneal, a combination of 0.1% retinaldehyde/6% glycolic acid, is effective and well tolerated in mild to moderate acne vulgaris.

Topical Retinaldehyde with Glycolic Acid: Study of Tolerance and Acceptability in Association with Anti-Acne Treatments in 1,709 Patients

BACKGROUND

Retinaldehyde (RAL), a key metabolite between vitamin A and retinoic acid, acts by modulating differentiation and proliferation of keratinocytes, which is of interest in acne lesions, mainly retentional lesions. Glycolic acid increases the exfoliation of corneocytes explaining its mild activity on retentional lesions. Thus, RAL and glycolic acid combined in the same product (Diacneal) have complementary activities which can be of interest for acne patients. The aim of this study was to evaluate the tolerance of Diacneal used by 1,709 acne patients in combination with their usual acne products except retinoids.

RESULTS

This study demonstrated a very good tolerance of Diacneal when used with other acne treatments for 90 days. Complaints about side-effects were rare. Moreover, the significant decrease in both inflammatory and retentional lesions between day 0 and day 90 indicates that Diacneal could amplify the efficiency of other anti-acne products used at the same time by the patients. The subjective evaluation of the preparation's efficacy by investigators and patients was strongly favourable.

CONCLUSION

These data show that a combination of RAL 0.1% and glycolic acid 6% may be used in association with other topical anti-acne treatments (benzoyl peroxide and topical antibiotics) with an excellent tolerance.

Acne: Topical treatment

Acne vulgaris is a common skin disease, affecting about 70-80% of adolescents and young adults. It is a multifactorial disease of the pilosebaceous unit.(1) The influence of androgens at the onset of adolescence leads to an enlargement of the sebaceous gland and a rise in sebum production. Additional increased proliferation and altered differentiation of the follicular epithelium eventually blocks the pilosebaceous duct, leading to development of the microcomedo as the primary acne lesion. Concomitantly and subsequently, colonization with Propionibacterium acnes increases, followed by induction of inflammatory reactions from bacteria, ductal corneocytes, and sebaceous proinflammatory agents (Fig 1).(2-5)

Developments in topical retinoid therapy for acne

Topical retinoic acid was introduced for acne treatment three decades ago. Since that time, researchers have discovered thousands of retinoids, originally defined as chemical analogs of vitamin A. After the identification of nuclear retinoid receptors in 1987, the definition of this class expanded to include molecules that bind to and activate such receptors. The receptor-selective retinoid agents, adapalene and tazarotene, were developed in the 1990s. Other innovations of the past decade include retinoid formulations and methods aimed at limiting retinoid absorption. Cutaneous irritation may be reduced without losing retinoid efficacy by inhibiting retinoid penetration into the deep epidermis and dermis. Examples include tretinoin in slow-release vehicles and the short-contact method of tazarotene gel therapy. Only trace amounts of adapalene are absorbed after topical application, perhaps explaining its relatively low irritancy. New formulations of existing agents, such as additional concentrations of tretinoin in microsphere gel and cream formulations of tazarotene, are now under investigation for acne. Current research focused on receptor selectivity holds the promise of yielding new retinoid molecules with improved benefits and safety.