Clobetasol propionate and pramoxine hydrochloride loaded nanolipid carrier gel for the treatment of atopic dermatitis†

Aim. To prepare and evaluate clobetasol propionate (CP) and pramoxine hydrochloride (PH) loaded nanolipid carrier (NLC)-based gel for improved skin permeation in the treatment of atopic dermatitis. Methodology. CP and PH-loaded NLCs were prepared by the melt emulsification ultrasonication technique. In vitro, ex vivo, and in vivo studies in the atopic dermatitis animal model of formulated drug-loaded NLC (DNLC) gel were evaluated. Dermal pharmacokinetic parameters were evaluated by Phoenix WinNonlin software. Results and discussions. DNLC gel was prepared successfully. Skin permeation and retentive property of the DNLC gel showed that CP from the DNLC had a permeability flux of 5.88 μg cm⁻² h⁻¹ and an enhancement ratio of 1.92 compared to a CP drug solution, while PH from the DNLC gel had a permeability flux of 9.52 μg cm⁻² h⁻¹ and an enhancement ratio of 1.62 compared to a PH drug solution. Dermal pharmacokinetic parameters were determined using WinNonlin software. CP retention at 24 h in stratum corneum, epidermis, and dermis was 4.25 ± 0.02 μg, 75.77 ± 0.01 μg, and 32.04 ± 0.012 μg, respectively, while PH retention at 24 h was 11.82 ± 0.003 μg, 344.0 ± 0.05 μg, and 172.85 ± 0.040 μg, respectively. More CP was retained from the DNLC gel than that from marketed CP cream. In vivo animal studies confirmed the effectiveness of DNLC gel in treating atopic dermatitis compared to commercial cream and individual drug-loaded DNLC gel, decreasing induced disease on a par with marketed CP cream. Epidermal thickness, immunoglobin E (IgE), and absolute eosinophil count (AEC) showed the greatest reduction in the DNLC gel treatment group.