Poly(L-lactide) proves useful as microencapsulation agent.(Brief Article)

2002 JUL 24 - (NewsRx.com & NewsRx.net) -- by Maria G. Essig, MS, ELS, senior medical writer - Ovalbumin, acting as a drug model, was successfully encapsulated in microparticles made of poly(L-lactide), according to researchers in Taiwan.

Antigens utilized in vaccines are often microencapsulated to provide a long-lasting immune response, protect the antigen or other encapsulated materials, and eliminate the need for booster inoculations. J.L. Chen and colleagues at the National Defense Medical Center in Taiwan described a method of preparing microparticles consisting of poly(L-lactide).

The investigators employed ovalbumin as a surrogate vaccine protein. A water-in-oil-in-water emulsion technique was used encapsulation (The mechanism of PLA microparticle formation by water-in-oil-in-water solvent evaporation method, Journal of Microencapsulation, 2002;19(3):333-346).

Researchers dissolved poly(L-lactide) (PLA) in dichloromethane as the dispersed phase; aqueous polyvinyl pyrolidone (PVP) acted as the continuous phase. Excessive leakage of ovalbumin from the particles was corrected by adding sodium chloride (5% w/v) to the continuous phase, which reduced solidification time. Within 10 minutes, the suspension solidified.

Results indicated successful entrapment of the ovalbumin within PLA microparticles with a particle size of 14 [micro ...