Curcumin is a poorly water-soluble drug that is used for the treatment of inflammations, tumors, wound healing antioxidant and other diseases. In the current manuscript, it is successfully formulated into proniosome gels. The proniosomes are readily hydrated into niosomal formulations using warm water. Proniosomes were prepared using nonionic surfactants (tween 80, span 60) either solely or in combinations with cholesterol. The produced niosomal formulations were homogenous in size with vesicular sizes >343 and <1800 nm. The encapsulation efficiency percentage “EE%” of curcumin in niosomal formulations was different according to niosomal composition. It increased up to 99.74% in formulations of tween 80/Chol of 200 μmole/mL lipid concentration. Span 60/chol niosomes showed decreased curcumin EE%. Niosomal formulations showed increased SSTF and PC with enhancement ratios of more than 20-fold compared with curcumin suspension form. Kinetically, niosomes fitted to the Korsemeyer-Peppas model with non-Fickian transport according to their calculated n-values where curcumin suspension form showed Korsemeyer-Peppas kinetics with Fickian transport. Niosomal formulations deposited higher curcumin amounts in the skin compared with the suspension form. The best niosomal formulation (F9) was used for niosomal gel and emulgel fabrication. Finally, the anti-inflammatory activity of curcumin in various formulations was evaluated using a rat hind paw edema method and the % of swelling was 17.5% following 24 h in group treated with curcumin niosomal emulgel. In conclusion, this study suggests that the developed niosomal emulgel could significantly enhance the anti-inflammatory effect of curcumin and be an efficient carrier for the transdermal delivery of the drug.

Transdermal delivery of insulin is a great challenge due to its poor permeability through the skin. The aim of the current investigation was to evaluate the prospective of insulin loaded niosome emulgel as a noninvasive delivery system for its transdermal therapy. A 2³ full-factorial design was used to optimize the insulin niosome emulgel by assessing the effect of independent variables (concentration of paraffin oil, Tween 80 and sodium carboxymethyl cellulose) on dependent variables (in vitro release, viscosity and in vitro permeation). The physical characteristics of the prepared formulations were carried out by determining viscosity, particle size, entrapment efficiency, drug loading, drug release and kinetics. In vitro permeation studies were carried out using rat skin membrane. Hypoglycemic activity of prepared formulations was assessed in diabetic-induced rats. It was observed that the independent variables influenced the dependent variables. A significant difference (p < 0.05) in viscosity was noticed between the prepared gels, which in turn influenced the insulin release. The order of permeation is: insulin niosome emulgel > insulin niosome gel > insulin emulgel > insulin gel > insulin niosomes > insulin solution. The enhancement in transdermal flux in insulin niosome emulgel was 10-fold higher than the control (insulin solution). In vivo data significantly demonstrated reduction (p < 0.05) of plasma glucose level (at six hours) by insulin niosome emulgel than other formulations tested. The results suggest that the developed insulin niosome emulgel could be an efficient carrier for the transdermal delivery of insulin.

Dermal drug delivery system which localizes methotrexate (MTX) in the skin is advantageous in topical treatment of psoriasis. The aim of the current study was to understand dilution effects and formulation variability for the potential formation of niosomes from proniosome gels of MTX. Box–Behnken’s design was employed to prepare a series of MTX proniosome gels of Span 40, cholesterol (Chol-X₁) and Tween 20 (T20-X₂). Short chain alcohols (X₃), namely ethanol (Et), propylene glycol (Pg) and glycerol (G) were evaluated for their dilution effects on proniosomes. The responses investigated were niosomal vesicles size (Y₁), MTX entrapment efficiency percent (EE%-Y₂) and zeta potential (Y₃). MTX loaded niosomes were formed immediately upon hydration of the proniosome gels with the employed solvents. Addition of Pg resulted in a decrease of vesicular size from 534 nm to 420 nm as Chol percentage increased from 10% to 30%, respectively. In addition, increasing the hydrophilicity of the employed solvents was enhancing the resultant zeta potential. On the other hand, using Et in proniosomal gels would abolish Chol action to increase the zeta potential value and hence less stable niosomal dispersion was formed. The optimized formula of MTX loaded niosomes showed vesicle size of 480 nm, high EE% (55%) and zeta potential of –25.5 mV, at Chol and T20 concentrations of 30% and 23.6%, respectively, when G was employed as the solvent. Hence, G was the solvent of choice to prepare MTX proniosomal gels with a maintained stability and highest entrapment.