Box-Behnken design avenue for development and validation of high-performance thin-layer chromatography method for estimation of rutin in Hemidesmus indicus

Dispersive liquid-liquid microextraction and Monte Carlo simulation of margin of safety for octocrylene, EHMC, 2ES, and homosalate in sunscreens

Dispersive liquid-liquid microextraction (DLLME) using a floating organic drop has been optimized and used for the sample preparation of four commonly used ultraviolet filter (UVF) substances in sunscreens. Plackett-Burman experimental design was used to screen 10 variables in DLLME. The most significant variables were then optimized by using a response surface method with a Box-Behnken design. DLLME followed by an optimized HPLC identified octocrylene, 2-ethylhexyl-4-methoxycinnamate, ethylhexyl salicylate, and homosalate as the frequently found UVFs in commercial sunscreens. The systemic exposure dosage and margin of safety (MoS) for the identified UVFs were estimated using in-use concentrations and application patterns. The average systemic exposure dosage values for octocrylene, 2-ethylhexyl-4-methoxycinnamate, ethylhexyl salicylate, and homosalate were 0.52, 0.61, 0.020, and 0.079 mg/kg body weight per day, respectively. Whereas the average MoS values for individual UVFs ranging from 296 to 3160 were all significantly higher than the limit value of 100, the combined exposure risks were slightly above the limit. The probabilistic health risk assessment using Monte Carlo simulation revealed that the combined MoS values were (mean, 10‰, 90‰) 342, 119, and 441, respectively. Regarding the usage of sunscreen cosmetics containing the UVFs studied, these results indicate a safety concern for those who apply multiple UVF products.

Development of andrographolide-loaded solid lipid nanoparticles for lymphatic targeting: Formulation, optimization, characterization, in vitro, and in vivo evaluation

Andrographolide, the primary bioactive constituent of Andrographis paniculata, is a promising natural substance with numerous pharmacotherapy uses. Low water solubility, short half-life, and low permeability necessitate the development of a delivery system that enhances its entrapment efficiency, bioavailability, lymphatic targeting, and by-pass hepatic effect. The andrographolide-loaded solid lipid nanoparticles were fabricated by melt-emulsification and ultrasonication and optimized with Design-Expert software. In the optimal formulation, Glycerol monostearate as the solid lipid and Poloxamer 407 and Span 60 as surfactants were used. Optimum AND-SLN was observed to have a mean particle size, polydispersity index, zeta potential, and entrapment efficiency of 193.84 nm, 0.211, - 22.8 mV, and 83.70% respectively. An optimized formulation was characterized by examining surface morphology, X-ray diffraction, and differential scanning calorimetry. In vitro studies have shown sustained drug release from AND-SLN for up to 24 h. The stability studies showed that there was no significant change in the mean particle size and entrapment efficiency after storage at 4 ± 2 °C and 25 ± 2 °C/60 ± 5% RH. In in vivo pharmacokinetics studies, AND-SLN was found to have enhanced bioavailability and specificity in the spleen and thymus compared to plasma, providing evidence that the formulations could enhance target specificity and bioavailability in comparison to pure drugs. The H&E staining of the liver, spleen, and thymus treated with the AND-SLN revealed no signs of damage histopathologically. Thus, AND-SLN possess a high potential for improved efficacy and are an efficient vehicle for delivering drugs to the lymphatic system.