Encapsulation and Release Properties

Verrecchia et al (1993, 1995) entrapped another water-insoluble drug, [ CJibuprofen ([ C]-IBP), in PEG2K-PLA30K nanospheres. The in vivo data after i.v. administration of the particles in rats showed an increase of IBP plasma half-life, firom a few minutes when encapsulated in non-stealth PLGA nanospheres up to two and a half hours in the case of stealth  

PEG-PLA nanospheres (Verrecchiae a/., 1993). Consequently, after 24hr, the area under the curve (AUC) of [ CJ-IEP pharmacokinetics is increased by a factor of 12 (Verrecchia et ah, 1995). 

Tissue distribution studies 6 hr after injection of PEG-PLA nanospheres revealed that 53% of the injected dose was in the intestines, 11.3% in the liver, and 9.1% in plasma in the case of PLGA nanospheres, 52.2% of the dose was in the intestines, 20% in the liver, and 0.39% in plasma (Verrecchia et al, 1995). IBP is a drug with a fast hepatic metabolism and an intestinal and fecal elimination, and the tissue distribution of the drug is not modified in both cases (PEG-PLA and PLGA nanoparticles), except for the plasma residence time. 

Encapsulation Properties of PEG-PLGA, PEG3-PLA, and PEG-PSA Polymers Influence of the Theoretical Loading on the Mean Diameter (Measured by QELS) 

Pol5Tner structure Mean diameter (nm) for a theoretical dmg loading of Actual dmg loading (wt. %) for a theoretical dmg loading of  

---