• Journal Article

Aerosolized Aqueous Suspensions of Poly(L-Lactic Acid) Microspheres


Masinde, L. E., & Hickey, A. (1993). Aerosolized Aqueous Suspensions of Poly(L-Lactic Acid) Microspheres. International Journal of Pharmaceutics, 100(1-3), 123-131. DOI: 10.1016/0378-5173(93)90083-R


A method is described for the preparation of microspheres of poly(L-lactic acid) possessing suitable characteristics for aerosolization. Microscopic analysis of the sample revealed a median projected area diameter of 4.2 mum, with a geometric standard deviation of 1.7. Electrical resistance particle size analysis showed that approx. 1% of the population had a size > 12.1 mum, and only 16.6% exceeded 5.5 mum. Scanning electron micrographs show well formed, round and smooth microspheres. Jet nebulization of an aqueous suspension produced a mass output of 44.4% of the microspheres over a period of 30 min. Aerodynamic particle size measurement showed that 51.2%, by number (approx. 16.9%, by volume) of the aerosol generated was < 2.1 mum in diameter. Greater than 80%, by volume, of the aerosol was smaller than 5.8 mum in aerodynamic diameter