PREPARATION AND CHARACTERIZATION OF COPOLY(DL-LACTIC GLYCOLIC ACID) MICROPARTICLES FOR SUSTAINED-RELEASE OF THYROTROPIN-RELEASING-HORMONE BY DOUBLE NOZZLE SPRAY-DRYING METHOD
S. Takada et al., PREPARATION AND CHARACTERIZATION OF COPOLY(DL-LACTIC GLYCOLIC ACID) MICROPARTICLES FOR SUSTAINED-RELEASE OF THYROTROPIN-RELEASING-HORMONE BY DOUBLE NOZZLE SPRAY-DRYING METHOD, Journal of controlled release, 32(1), 1994, pp. 79-85
Copoly(dl-lactic/glycolic acid) microparticles for sustained release o
f a water soluble drug (Thyrotropin releasing hormone: TRH) were prepa
red by a spray drying method. In the case of double nozzle spray dryin
g (DNSD) using acetonitrile, the effect of TRH loading amount on the i
nitial burst was smaller than that with in-water drying. The micropart
icles prepared by DNSD and loaded with up to 10% TRH exhibited a small
initial burst followed by a constant release rate over 4 weeks. The d
rug release from the polymer was much faster than the polymer weight l
oss. The mean particle size of the spray dried microparticles was smal
ler than that with in-water drying. Acetonitrile used in DNSD is a les
s toxic organic solvent than dichloromethane, and the residual amount
in the microparticles was similar to that in the in-water drying metho
d. In conclusion, the production of biodegradable microparticles by th
e double nozzle spray drying method should be an attractive alternativ
e to conventional microencapsulation methods.