METHODS: A cross-sectional study was performed. MED was determined using a handheld device with wavelength of 311 nm. Vitiligo severity was measured using the Vitiligo Area Scoring Index (VASI) while disease activity was assessed by the Vitiligo Disease Activity (VIDA). Sun exposure was quantified by the Sun Exposure Index (SEI).
RESULTS: A total of 36 patients (mean age of 49.06 ± 21.29 years old) participated with 12 patients from each skin phototype. MEDs of skin affected by vitiligo were 255 ± 120.3, 280 ± 93.4, and 525 ± 226.1 mJ/cm2 for phototypes III, IV, and V respectively. The MEDs of unaffected skin were 465 ± 120.3, 580 ± 123.6, and 1150 ± 116.8 mJ/cm2 for phototypes III, IV, and V respectively. The MEDs for skin affected by vitiligo were 45%, 52%, and 54% less than the MEDs of unaffected skin for phototypes III, IV, and V respectively. The differences in MEDs between vitiligo-affected skin and unaffected skin were significant for all skin phototypes (p skin with vitiligo negatively correlated with vitiligo severity, r = -0.426, p = 0.01. There were no significant correlations between MED and VIDA, disease duration, or SEI.
CONCLUSION: MED of skin with vitiligo was much lower than unaffected skin, and MEDs between skin phototypes III, IV, and V differed despite similar depigmentation. MED was not influenced by vitiligo disease activity, duration, or sun exposure.
Methods: Colchicine-loaded transethosomes (TEs) were prepared by the cold method and statistically optimized using three sets of 24 factorial design experiments. The optimized formulations were incorporated into Carbopol 940® gel base. The prepared colchicine-loaded transethosomal gels were further characterized for vesicular size, dispersity, zeta potential, drug content, pH, viscosity, yield, rheological behavior, and ex vivo skin permeation through Sprague Dawley rats' back skin.
Results: The results showed that the colchicine-loaded TEs had aspherical irregular shape, nanometric size range, and high entrapment efficiency. All the formulated gels exhibited non-Newtonian plastic flow without thixotropy. Colchicine-loaded transethosomal gels were able to significantly enhance the skin permeation parameters of the drug in comparison to the non-ethosomal gel.
Conclusion: These findings suggested that the transethosomal gels are promising carriers for the transdermal delivery of colchicine, providing an alternative route for drug administration.
METHODS: This work reports the application of an X-ray microbeam via synchrotron SAXS/WAXS analysis to monitor drug crystallization in the skin, especially in the deeper skin layers. Confocal Raman spectroscopy (CRS) was employed to examine drug distribution in the skin to complement the detection of drug crystallization using SAXS/WAXS analysis.
RESULTS: Following application of saturated drug solutions (ibuprofen, diclofenac acid, and salts), CRS depth profiles confirmed that the drugs generally were delivered to a depth of ~15 - 20 µm in the skin. This was compared with the WAXS profiles that measured drug crystal diffraction at a depth of up to ~25 µm of the skin.
CONCLUSION: This study demonstrates the potential of synchrotron SAXS/WAXS analysis for profiling of drug crystallization in situ in the deeper skin layers without pre-treatment for the skin samples. [Figure: see text].