Parameters influencing the antigen release from spray-dried poly(DL-lactide)
microparticles.
Baras B, Benoit MA, Gillard J
Laboratoire de Pharmacie Galenique, Industrielle et Officinale, Ecole
de Pharmacie, Universite Catholique de Louvain, Brussels, Belgium. benoit.baras@pasteur-lille.fr
[Medline record in process]
Microparticles were produced by spray-drying from a high molecular weight
polylactide (PLA R207) for the development of long-lasting controlled release
systems of vaccines, which may be designed to obviate the need for booster
doses. The current investigation considered the effect of both technological
parameters (inlet air temperature and spray rate of feed) and polymeric
solutions (polymer concentration and nature of organic solvents) on characteristics
of microparticles (morphology, size and antigen loading) containing a water-soluble
model antigen (bovine serum albumin, BSA). Following parameters chosen,
microparticles were characterized by a mean size from 3.08 +/- 0.06 to
9.43 +/- 0.26 microm and a BSA loading from 2.45 +/- 0.13 to 18.20 +/-
2.25% (w/w). The BSA release rate from microparticles varied from 11.17
+/- 2.20 to 92.60 +/- 3.46% in 24 h. The modification of the inlet temperature,
the spray-rate of feed or the use of a mixture of dichloromethane/chloroform
(DCM/CFM) instead of DCM alone resulted in the modification of the BSA
burst release. This burst release was followed by a BSA release rate slower
for microparticles with a low BSA loading. Moreover, the increase of the
R207 concentration resulted in a decrease of the BSA release rate while
the burst release was not modified. SDS-PAGE electrophoresis and isoelectric
focusing analyses of the BSA released from microparticles confirmed the
preservation of its physicochemical characteristics. Together, results
showed that the spray-dried microparticles loaded with hydrophilic antigen
could be used as a potential delivery system for the long-lasting controlled
release of vaccines.
PMID: 10845695, UI: 20302318