Adapalene-loaded poly(ε-caprolactone) microparticles: Physicochemical characterization and in vitro penetration by photoacoustic spectroscopy.

Adapalene (ADAP) is an important drug widely used in the topical treatment of acne. It is a third-generation retinoid and provides keratolytic, anti-inflammatory, and antiseborrhoic action. However, some topical adverse effects such as erythema, dryness, and scaling have been reported with its commercial formula. In this sense, the microencapsulation of this drug using polyesters can circumvent its topical side effects and can lead to the enhancement of drug delivery into sebaceous glands. The goal of this work was to obtain ADAP-loaded poly(ε-caprolactone) (PCL) microparticles prepared by a simple emulsion/solvent evaporation method. Formulations containing 10 and 20% of ADAP were successfully obtained and characterized by morphological, spectroscopic, and thermal studies. Microparticles presented encapsulation efficiency of ADAP above 98% and showed a smooth surface and spherical shape. Fourier transform infrared spectroscopy (FTIR) results presented no drug-polymer chemical bond, and a differential scanning calorimetry (DSC) technique showed a partial amorphization of the drug. ADAP permeation in the Strat-M membrane for transdermal diffusion testing was evaluated by photoacoustic spectroscopy (PAS) in the spectral region between 225 and 400 nm after 15 min and 3 h from the application of ADAP-loaded PCL formulations. PAS was successfully used for investigating the penetration of polymeric microparticles. In addition, microencapsulation decreased the in vitro transmembrane diffusion of ADAP.

Comparison of efficacy of aminolaevulinic acid photodynamic therapy vs. adapalene gel plus oral doxycycline for treatment of moderate acne vulgaris-A simple, blind, randomized, and controlled trial.

BACKGROUND: Although progress has been made in the study of photodynamic therapy for acne, studies using current recommended therapies as active comparators are lacking. METHODS: Randomized, controlled trial involving 46 patients with moderate inflammatory facial acne, 23 patients received two sessions of PDT separated by 2 weeks (ALA 20% incubated 1.5 hours before red light irradiation with 37 J/cm2 fluence) and 23 patients received doxycycline 100 mg/d plus adapalene gel 0.1%. In both groups, from the sixth week, we started adapalene gel 0.1% as maintenance therapy until 12 weeks of follow-up. Primary end point was the reduction of acne lesions at the 6-week follow-up, which was evaluated by 2 investigators blinded to the intervention. RESULTS: The median percent reductions in noninflammatory lesion count (P = 0.013) and total lesions (P = 0.038) at 6 weeks was found to be significantly higher in the group receiving PDT. At 12 weeks there was a greater reduction of inflammatory lesions in PDT group with 84% vs. 74% for group who received doxycycline plus adapalene (P = 0.020) as well as in reducing total lesions with 79% vs. 67% respectively (P = 0.026). No severe side-effects were observed for either therapy. CONCLUSIONS: ALA-PDT offers promise as an alternative treatment for moderately severe inflammatory acne that has a higher effectiveness than the combination of doxycycline and adapalene gel in reducing noninflammatory and total lesions at 6 weeks. There were significantly superior reductions at 12 weeks in the combination of PDT group followed by adapalene gel in total, inflammatory, and noninflammatory lesions.

Comparable efficacy of adapalene 0.3% gel and tretinoin 0.05% cream as treatment for cutaneous photoaging.

BACKGROUND: Adapalene has been previously evaluated as a treatment for actinic keratosis (AK) and solar lentigines and shown to improve signs of photoaging. OBJECTIVES: To evaluate whether adapalene 0.3% gel is non-inferior to tretinoin 0.05% cream as treatment for photoaged skin. MATERIALS & METHODS: An investigator-blinded, parallel-group comparison study was conducted in Brazil. Subjects were randomised in a 1:1 ratio to receive, once daily, adapalene 0.3% gel or tretinoin 0.05% cream. Subjects were evaluated at Weeks 1, 4, 8, 12, 16, 20 and 24, based on clinical signs of cutaneous photoaging, histopathological and digital morphometric findings, as well as safety and tolerability. RESULTS: A comparison of clinical efficacy showed that both treatments did not differ significantly regarding clinical evaluation of the following criteria: global cutaneous photoaging, periorbital wrinkles, ephelides/melanosis, forehead wrinkles, and AK. CONCLUSION: Adapalene 0.3% gel showed non-inferior efficacy to tretinoin 0.05% cream as treatment for photoaged skin, with a similar safety profile. Adapalene 0.3% gel may therefore be considered a safe and effective option for the treatment of mild or moderate photoaging.