Effect of curcumin-micelles adopting vitamin E-TPGS and Solutol HS 15 as carriers on solubility and oral bioavailability of curcumin / 中草药

Objective: To prepare curcumin-micelles adopting vitamin E-TPGS (VE-TPGS) and Solutol HS15 (SHS15) as carriers, and study the effect on solubility and oral bioavailability of curcumin (Cur). Methods: Cur was loaded into micelles between VE-TPGS and SHS15 by thin film dispersion method. Particle size, loading efficiency, entrapment efficiency, and in vitro release were carried on to estimate the influence of micelles on Cur; Moreover, oral bioavailability in rats was also evaluated. Results: The particle size was (35.79 ± 1.23) nm with polydispersity index (PDI) of 0.12 ± 0.03 when the optimized micelles ratio was at 3:7 of VE-TPGS and SHS15, which increased the solubility of Cur to 2.03 mg/mL in water. The entrapment efficiency and drug loading were 90.03% and 9.34%, respectively. The in vitro release profile showed a sustained release property compared with that of Cur. In addition, the relative bioavailability of micelles (AUC0~∞) compared with that of Cur (AUC0~∞) was 303.5% (P < 0.01). Conclusion: The Cur-micelles combined use of VE-TPGS and SHS15 shows great potential clinical application.

Liquid crystalline systems containing Vitamin E TPGS for the controlled transdermal nicotine delivery

ABSTRACT Transdermal nicotine patches have been used in smoking cessation therapy, suggested for the treatment of skin disorders with eosinophilic infiltration and have been found to improve attention performance in patients with Alzheimer's disease and age-associated memory impairment. However, skin irritation with extended patch use is still a problem. The aim of this work was to develop a simple to prepare liquid crystalline system containing vitamin E TPGS that would be able to control nicotine delivery and reduce irritation and sensitization problems. The liquid crystalline phases were macroscopically characterized by visual analysis and examined microscopically under a polarized light microscope. Topical and transdermal delivery of nicotine were investigated in vitro using porcine ear skin mounted on a Franz diffusion cell. Nicotine skin permeation from the developed cubic phase followed zero-order kinetics (r = 0.993) and was significantly enhanced after 12 h when compared to the control formulation (nicotine solution) (p < 0.05) (138.86 ± 20.44 and 64.91 ± 4.06 μg/cm2, respectively). Cubic phase was also able to target viable skin layers in comparison to control solution (8.18 ± 1.89 and 2.63 ± 2.51 μg/cm2, respectively). Further studies to evaluate skin sensitization and irritation are now necessary.

RESUMO Adesivos transdérmicos de nicotina são utilizados para cessação de fumar, tratamento de problemas de pele com infiltração de eosinófilos e para melhorar a atenção em pacientes com doença de Alzheimer e enfraquecimento da memória associada à idade. No entanto, a irritação da pele com o uso prolongado dos adesivos ainda é um problema. O objetivo deste trabalho foi desenvolver sistema líquido cristalino (SLC) de preparo simples contendo vitamina E TPGS capaz de controlar a liberação de nicotina e reduzir os problemas de irritação cutânea. Os SLCs foram caracterizados por análise visual e microscopia de luz polarizada. As administrações tópica e transdérmica de nicotina foram investigadas in vitro utilizando pele de orelha de porco em célula de difusão de Franz. A permeação da nicotina veiculada pela fase cúbica desenvolvida seguiu cinética de ordem zero (r = 0,993) e foi significativamente maior do que o controle (solução de nicotina) após 12 h (p < 0,05) (138,86 ± 20,44 e 64,91 ± 4,06 µg/cm2, respectivamente). A fase cúbica também promoveu aumento da penetração de nicotina nas camadas viáveis da pele quando comparado ao controle (8,18 ± 1,89 e 2,63 ± 2,51 µg/cm2, respectivamente). Estudos futuros para avaliar a sensibilização e irritação da pele são necessários.