PT - JOURNAL ARTICLE AU - Takada, Shigeyuki AU - Uda, Yoshiaki AU - Toguchi, Hajime AU - Ogawa, Yasuaki TI - Application of a Spray Drying Technique in the Production of TRH-Containing Injectable Sustained-Release Microparticles of Biodegradable Polymers. DP - 1995 Jul 01 TA - PDA Journal of Pharmaceutical Science and Technology PG - 180--184 VI - 49 IP - 4 4099 - http://journal.pda.org/content/49/4/180.short 4100 - http://journal.pda.org/content/49/4/180.full SO - PDA J Pharm Sci Technol1995 Jul 01; 49 AB - Copoly (dl-lactic/glycolic acid) microparticles for sustained release of a water-soluble drug (Thyrotropin releasing hormone: TRH) were prepared by a spray drying method. A higher entrapment ratio was achieved with the spray drying method than with the in-water drying method. In order to avoid agglomeration of the microparticles, a double-nozzle spray drying method was designed using mannitol as an anti-adherent. The surface of the spray-dried microparticles was coated with mannitol, and the extent of agglomeration was decreased. Acetonitrile was the most suitable solvent for microencapsulation using the double-nozzle spray drying method because the initial burst of TRH from the microparticles during the first day was the smallest. When PLGA with a weight-average molecular weight of 14,000 was used, constant release of TRH continued for one month with a small initial burst. In conclusion, the production of biodegradable microparticles by the double-nozzle spray drying method appears to be an attractive alternative to conventional microencapsulation methods.