Study On The Brain Targeting Solid Lipid Nanoparticles Loaded With Ganciclovir

Objective:To prepare the borneol-modified ganciclovir-loaded solid lipid nanoparticles(GCV-SLN)and investigate the effect of borenol on the transcellular transport of GCV in vitro blood-brain barrier(BBB)model which were based on the MDCK and MDCK-MDR1 cell monolayer and the effect of borenol on the pharmacokinetics of ganciclovir(GCV)in mice and rats,which was looked forward to reveal the mechanism of enhancement the brain targeting of GCV which was loaded in the borneol-modified solid lipid nanoparticles.Methods:HPLC methods were developed to determine the equibrium solubility of GCV,content,encapsulation efficiency,in vitro release and the concentration of samples in vivo.The borneol modified GCV SLN were made from the emulsifier A and emulsifier B based on microemulsion method according to the results of orthogonal design,and the content of borneol which was described as the mass ratio to the carries were set as 0%,10%,15%and 20%,respectively.The physico-chemical characteristics of prepared SLNs were investigated as follows:the mean diameter and Zeta were determined with a dynamic light scattering(DLS)method,the entrapment efficiency was determined with ultrafiltration method,a Franz diffusion cell method was used to detect the GCV in vitro release and the stability experiment was conducted at 4?.The MDCK and MDCK-MDR1 cell monolayer were developed as the in vitro blood-brain barrier(BBB)model to investigate the transcellular transport of GCV and on which the effect of bomeol was discussed.The effect of borneol on the biodistribution of GCV in mice and the pharmacokinetics in rats were also evaluated after the intravenous administration of GCV-inj and the prepared SLNs.Results:The oil-water partition coefficient(lgP)on GCV in PBS(pH 7.4)and n-octanol was-0.209 at 37?.The prepared SLNs with the two kinds of emulsifier showed a mean diameter between 110nm and 145nm and with the mean entrapment efficiency between 60%and 68%.The Ritger-Peppas and Weibull model were more favorable to describe the release mechanism of GCV in vitro.Stability experiment results indicated that the SLNs made from emulsifier A and emulsifier B should be kept stable at 40C for 3 months.The results of transcellular transport in vitro blood-brain barrier(BBB)model showed that GCV transported the MDCK monolayers by passive diffusion and was inhibited by the function of efflux of P-glycoprotein(P-gp)in MDCK-MDR1 monolayers.The Pappof GCV with the concentration of 500?g·mL-1 had good linear relationship with the content of borneol in the prepared SLNs in MDCK monolayers.Both SLNs made from emulsifier A had higher Papp than the SLNs made from emulsifier B in the two cell monolayers.After injection at a single dose of 35mg·kg-1 GCV in the formulations GCV-inj,AGCN-SLN,AGCVb-SLN1 AGCVb-SLN2 and AGCVb-SLN3,the pharmacokinetics parameters in mice were as follows:MRT were 39.14?51.01?50.50?58.64 and 83.97min,respectively,Cmax in the brain were:(3.96±0.67)?(4.63± 1.44),(9.53±2.81),(10.25±2.50)and(12.95±13.62)?g·g-1,respectively,the formulations modified with borneol showed significant difference compared with GCV-inj and AGCN-SLN,AUCo-t,in the brain were:134.99,337.97,985.71,1076.01 and 716.86?g·min·g-1,respectively,and the drug targeting index(DTI)for AGCN-SLN,AGCVb-SLN1,AGCVb-SLN2 and AGCVb-SLN3 were 1.83,4.78,5.36 and 2.94,respectively.The pharmacokinetic parameters after intravenous administration of GCV-inj,AGCN-SLN,AGCVb-SLNl1 AGCVb-SLN2 and AGCVb-SLN3 at a single dose of 25mg.kg-1 GCV in the formulations in rats were as follows:AUCO-?:(85.01±7.96),(106.1 ? 11.54),(104.35±9.42),(110.96±8.88)and(118.94±14.70)?g·h·mL-1,respectively,MRT:(2.52±0.11),(2.8010.09),(2.81 ±0.10),(3.11 ±0.07)and(2.89±0.08)h,respectively,The terminal elimination constant Ke:(0.43±10.04),(0.32±0.02),(0.31±0.03),(0.30±0.01)and(0.31±0.02)h-1,respectively.Conclusions:The borneol-modified ganciclovir-loaded solid lipid nanoparticles were prepared successfully,the bomeol-modified ganciclovir-loaded solid lipid nanoparticles can enhance the transcellular transport of GCV in vitro BBB model,the SLNs made from emulsifier A can raise the transport of GCV to brain of mice and highlight the concentration of GCV in brain,and the bomeol-modified ganciclovir-loaded solid lipid nanoparticles can increase the A UC in plasma and prolong the MRT in rats.