Formulation conditions on the drug loading properties of polymeric micelles.

Methyl poly(ethylene glycol) grafted poly (lactide-co-(glycolic acid)-alt-(glutamic acid) amphiphilic copolymers (PLG-g-mPEG) were fabricated polymeric micelles to load anticancer drug doxorubicin (DOX). Both blank and drug loaded micelles were spherical nanoparticles with the mean sizes around 50 and 100nm, respectively. The effects of formulation conditions including compositions, concentrations, temperature, feeding doses and solvents on the size and drug loading content were investigated, the storage of the drug loaded micelles was explored. The results showed that the short graft mPEG chain length was favorable for the loading of DOX. The increase of temperature was preferable for receive micelles with higher drug loading content and smaller size. The encapsulation of polymeric micelles could protect the bioactivity of DOX. In vitro drug release profiles illustrated that the drug release from polymeric micelles with long mPEG chains was much faster than from micelles with short mPEG chains. The release kinetics of drug from micelles fitted to the Ritger-Peppas equation well and the release process followed diffusion mechanism.

[Enhancers on the transmembrane transport of chlorogenic acid].

To investigate the influence of the difference enhancers on the transport mechanism of chlorogenic acid (CGA) across Caco-2 cells model, a RP-HPLC method was adopted to detect the concentrations of CGA. At the concentrations of 20 to 80 microg x mL(-1), the difference of absorption rate constants (K(a)) was not statistically significant. At the concentrations of 40 and 20 microg x mL(-1), the ratios of apparent permeability coefficients (P(app)) of the apical to basolateral and the basolateral to apical were 1.14 and 1.18, respectively. With the effect of enhancers K(a) and P(app) increased, the absorption half-life (T1/2) decreased. CGA passed through the Caco-2 cell membrane mainly by passive transport. It showed that monocarboxylic acid transporter (MCT) could be involved in the across membrane transport process of CGA. Borneol had no effect on the cell membrane transport processes. The order of increasing absorption of CGA caused by the enhancers was sodium lauryl sulphate > sodium taurocholate > carbomer.

[The pharmacokinetic study on cytarabine nanoparticle lyophilization injection in rabbits].

OBJECTIVE: The pharmacokinetics of Cytarabine Polybutylcyanoacrylate Nanoparticles (Ara-C-PBCA-NP) lyophilization injection in rabbits was studied. METHODS: Ara-C water solution was taken as reference, the concentration of Ara-C was determined by HPLC, and the pharmacokinetic parameters were calculated. RESULTS: Pharmacokinetic properties of Ara-C water solution and Ara-C-PBCA-NP lyophilization injection complied with two-department model. The parameters t1/2 beta and MRT of Ara-C-PBCA-NP lyophilization injection were prolonged, and CL was reduced dramatically (P < 0.05). CONCLUSION: Ara-C-PBCA-NP lyophilization injection possesses prolonged retention time in vivo and significant sustained releasing character.