Green formulation of spironolactone loaded chitosan coated nano lipid carrier for treatment of acne vulgaris: a randomized double-blind clinical trial

Purpose: Spironolactone (SPN), which is classified as an anti-androgen, has demonstrated efficacy in treating acne. This study aimed to utilize ultrasonication to create a chitosan-coated nano lipid carrier (NLC) for enhancing the delivery of SPN to the skin and treating acne. Methods: Various Hydrophilic-Lipophilic Balance (HLB) values were investigated to optimize the SPN-NLCs. Photon correlation spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) were employed to characterize the solid state of SPN in nanoparticle form. Additionally, the optimized formulation was used in a double-blind, randomized clinical trial. Results: Reducing the HLB of the surfactant mixtures resulted in a reduction in the size of SPN-NLCs. The formula with the smallest particle diameter (238.4±0.74 nm) and the lowest HLB value (9.65) exhibited the highest encapsulation efficiency of 79.88 ± 1.807%. Coating the optimized SPN-NLC with chitosan increased the diameter, PDI, zeta potential, and encapsulation efficiency. In vitro skin absorption studies demonstrated sustained release profiles for chitosan-coated SPN-NLC. In the double-blind trial, a gel containing chitosan-coated SPN-NLC effectively treated mild to moderate acne vulgaris, leading to improved healing and reduced lesion count after 8 weeks of therapy compared to the placebo. It successfully addressed both non-inflammatory and inflammatory lesions without adverse effects on the skin. Conclusion: The findings indicate that chitosan-coated SPN-NLCs have the potential as nanoparticles for targeted SPN delivery to the skin, offering novel options for the treatment of acne vulgaris.