Studies On The Cobro α-neurotoxin Loaded Polylactic Acid Nanoparticles

Objective To prepare NT-â…  loaded Polylactic acid Nanoparticles and investigate the possibility of them for nasal administration. Methods NT-â…  -PLA-NPs were prepared by a double emulsion method. Their pharmaceutical characters in vitro,pharmacokinetics in vive through nasal administration were studied respectively. The research of pharmaceutical characters in vitro included: Morphology of NT- â…  -PLA-NPs were examined by transmission electronmicroscope (TEM); Measurement of Zeta potential and mean particle size were estimated by the use of photon correlation spectroscopy(PCS) and laser Doppler anemometry(LDA);Entrapment efficiency of NT-â…  -PLA-NPs were charactered by radioactive counting method; using radioactive counting method for determining NT- â…  concentration in plasma and using NT- â…  as the reference, the relative bioavailability and pharmacokinetics studies of NT- â…  were performed in rat. Results The Zeta potential,mean particle size,entrapment efficiency of NT- â…  -PLA-NPs were -13.4mV , 66.4nm and 35.2%, respectively. The half-release time(t₅₀) of NT- â…  -PLA-NPs was 12.3h .The in vitro profiles of NT- â…  -PLA-NPs could be described by first-order kinetic equation and it appeared to consist of two components with initial rapid release followed by a exponential stage. C_max of NT- â…  in NT- I -PLA-NPs and reference NT-â…  solution were 338.8 ± 8.4 pg/mL and 437.2±32.7pg/mL, respectively. T_max were 6.5 ± 0.5 h, 2.3 ± 0.6 h. AUC_0-t were 13156.1 ± 1004.7 pg·h /ml, 9128.4...