Nanotechnology is currently a hot topic in dermatology and nutraceutical/cosmeceutical delivery, owing to the advantages it provides in terms of enhancing the skin permeation of drugs, as well as increasing their therapeutic efficacy in the treatment of different dermatological diseases. There is also a great interest in the topical delivery of nutraceuticals; which are natural compounds with both therapeutic and cosmetic benefits, in order to overcome the side effects of topically applied chemical drugs. Quercetin is a key nutraceutical with topical antioxidant and anti-inflammatory properties which was reported to be effective in the treatment of different dermatological diseases, however, its topical therapeutic activity is hindered by its poor skin penetration. This review highlights the topical applications of quercetin, and summarizes the nanocarrier-based solutions to its percutaneous delivery challenges.

This study aimed to develop and verify a simple HPLC-based quantitative approach to simultaneously determine the phosphodiesterase-5 inhibitors (PDE5Is) sildenafil, vardenafil, udenafil, avanafil, and tadalafil in a tablet dosage form mixed with honey obtained form Jordanian market in rat plasma. PDE5Is block phosphodiesterase-5 (PDE-5). This blockage, in turn, triggers vasodilation by phosphorylating downstream effector molecules. Chromatographic separation was performed on a Hypersil^TM C₁₈ column (150 mm × 4.6 mm, 5 µm, Thermo Fisher Inc., Waltham, MA, USA). An acetonitrile:10% Triethylamine solution (57:43) at pH 5.5 (adjusted with orthophosphoric acid), 20 µL injection volume, 1 mL/min flow rate, 25 °C temperature, and eluent monitoring at 250 nm was used to execute the current approach. Linearity was observed in the 9.6–14.4 µg/mL concentration ranges for sildenafil, udenafil, avanafil, and tadalafil, and 2.4–3.6 µg/mL for vardenafil. Each dosage form was recovered within acceptable limits at three distinct concentrations, and the assay selectivity indicated no interference from the inactive substances in the formulation. Sildenafil, vardenafil, udenafil, avanafil, and tadalafil had retention times of 3.5, 4.3, 6.2, 9.7, and 12.8 min, respectively, and tadalafil was 12.8 min. The present analytical method is comprehensive and universal for measuring the five drugs. Such an analytical method can be routinely used to detect the combination of these drugs.

The aim of the current work was to elucidate whether the encapsulation of curcumin in nanoparticles (of microemulsion type) would allow its exertion of anticancer activity on several cancer cell lines or not. Curcumin microemulsion was prepared using the water dilution method, in which oleic acid constituted the oily phase, and tween 20, ethanol constituted the surfactant and cosurfactant respectively. The microemulsion was tested for its particle size, charge, morphology using transmission electron microscopy, in vitro curcumin release, stability and anticancer activity on HCT-116 colon cancer line, A549 lung cancer cell line, and PC3 prostate cancer cell line. The safety of the formulation was tested on fibroblasts cell line. Results revealed that curcumin microemulsion was successfully prepared with a particle size of 11.45±0.21 nm, and a negative charge of -9.07 mV, and it was able to sustain the release of drug for 24 hours with a cumulative percent released of 66.72%. Its spherical morphology was confirmed using transmission electron microscopy. No significant changes in particle size or charge were observed upon storage, suggesting the physical stability of the microemulsion. Curcumin microemulsion was proven safe on the normal fibroblasts cell line, and it preserved the anticancer activity of curcumin against A549, HCT116, and PC3 cell lines. Results of this study delineate that microemulsion is a suitable nanodelivery system for curcumin, which needs to be tested on animal tumor models for verification of the anticancer properties in vivo.