Studies On Coenzyme Q₁₀ Nanostructured Lipid Carriers Dispension And Gels

Coenzyme Q10(Q10) has many biochemical functions, such as ATP generating andantioxidant. Q10can reduce photoaging in vivo with a corresponding decrease in wrinkledepth, and has been used as an active ingredient in topical preparations and cosmetics.However, Q10is chemically unstable and easy to degrade when exposed to light.Nowadays, the pharmaceutical dermal products containing Q10are mostly ordinaryemulsion or gel, which do not show prolonged release and skin targeting property.Considering the chemical instability of Q10and the advantage of NLC in dermalapplication, the aim of this study was to prepare Q10-NLC increasing its epidermaltargeting and protecting Q10from degrading. Formulations and preparation parameterswere optimized by response surface design. In vitro release and skin permeation studieswere carried out. Long-term stability and light stability were evaluated. The main resultsare as follows:(1) Q10-NLC was prepared by high pressure microfluidics technique. Formulations andpreparation parameters were optimized with response surface design. The results showed that theconcentration of solid lipid and emulsifier in formulation had a significant influence on particlesize. The optimized preparation parameters were magnetic stirring for20min, high stirring at8000rpm for1min and high pressure microfluidics at1200bar for3cycles. The size of Q10-NLCprepared by optimized formulation and parameters was (151.7±2.31) nm, polydispersity (PDI)0.144, zeta potential was (-44.1±1.68) mV, drug loading2.51%, encapsulation efficiency100%.DSC and XRD results indicating Q10was in amorphous state.(2) HPLC method was selected to determine Q10. Q10had a good linear relationship in the scopeof50.0–350.0μg/mL. The stability of the solution was high and the accuracy was good, theaverage coefficient of recovery was99.93%.(3) Q10was degraded by alkali and light. Q10-NLC was not stable with acid, but long-termstability and light stability was good. After exposure to day light for24hours, the amount of Q10in Q10-NLC decreased only5.59%, while in Q10emulsion decreased24.61%and Q10-ethanol solution49.74%.(4) Q10-NLC carbomer and HPC-M gels were prepared. The penetration of Q10from theQ10-NLC formulations through skins and into skins were evaluated in vitro using Franz diffusioncells fitted with SD rat skins. In vitro release study, Q10-NLC showed fast release during the first3hours and prolonged release afterwards. In vitro skin permeation study, the accumulative uptake ofQ10in epidermal of Q10-NLC was10.11times over Q10emulsion.Q10-NLC exhibited a significant epidermal targeting effect, which was proved to be apromising carrier for topical delivery of Q10.