RT Journal Article SR Electronic T1 Application of a Spray Drying Technique in the Production of TRH-Containing Injectable Sustained-Release Microparticles of Biodegradable Polymers. JF PDA Journal of Pharmaceutical Science and Technology JO PDA J Pharm Sci Technol FD Parenteral Drug Association (PDA) SP 180 OP 184 VO 49 IS 4 A1 Takada, Shigeyuki A1 Uda, Yoshiaki A1 Toguchi, Hajime A1 Ogawa, Yasuaki YR 1995 UL http://journal.pda.org/content/49/4/180.abstract 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.