Pharmacokinetic research of Nerve Growth Factor packed with liposome

Objective: To study the pharmacokinetics of Nerve Growth Factor(NGF)-liposome in rabbit by isotopic tracing.Methods:① NGF was labeled with 99mTC ,and its γ-ray counts were detected by isotopic tracing and trichloroacetic acid(TCA)precipitation method. From cpm of γ-ray and NGF content of samples, the standard curve was drawn and it was nearly a line. ② 99mTC-NGF was packed with liposome and injected into rabbits(n = 5) body from vena auris.③ Blood samples of rabbit were collected at different times(0.5,1,3,5,10,15,30,60,90,120,150,180,210,240 min) after injection. The techniques above were used to detect NGF concentration in rabbit blood and data were input into computer to analyze the pharmacokinetic parameter by software(3P87). Results: The metabolism of NGF-Liposome in vivo in rabbits was fitted to the double-compartments model. With the dose of 40 mg/kg, the pharmacokinetics parameters were as the follows:t1/2 α = 0.2338 h,t1/2 β = 1.3229 h,AUC =106.57 ng/h·ml-1.Conclusion: NGF-liposome has some slowly-release function compared to NGF.