Characteristic and controlled release of anticancer drug loaded poly (D,L-lactide) microparticles prepared by spray drying technique

Anticancer drug release from polylactic acid microspheres prepared by the s pray-drying process was studied. Several process parameters and properties of the polymer solution have been investigated. Normal size distributions w ith diameters ranging from 5-10 mum were obtained by the spray drying techn ique. The yield of microspheres recovered depended on polymer solution and process conditions employed. Results show that the yield of microspheres co uld reach 50%, and the experimental drug loading approached the theoretical drug loading. Scanning electron microscopy indicated that microspheres wer e composed of a dense thin skin layer and porous core. The magnitude of thi s effect depended on the inlet temperature, feed polymer concentration and airflow rate. Increasing inlet temperature and polymer concentration result ed in an intact particle shape and a slower drug dissolution rate. The in-v itro release of anticancer drug from microspheres was sustained over 7 days . The drug release behaviour depended on inlet temperature, air flow rate, PLA concentration and drug loading. The anticancer drug release rate from p olylactic acid microspheres prepared by the spray-drying method was depress ed, and the long-acting release could be achieved by appropriate operating parameters.