Polyglycolide microspheres

Cleland JL. Design and production of single-immunization vaccines using polylactide polyglycolide microsphere systems. In Powell MF, Newman MJ, eds. Vaccine Design The Subunit and Adjuvant Approach. New York Plenum Press 1995. 

The use of polylactides for delivery of insect hormone analogs and other veterinary compounds (115,116) has been studied. Microspheres, pellets, and reservoir devices based on polyglycolide, poly-(DL-Iactide), poly(L-lactide), and various copolymers have been used to deliver methoprene and a number of juvenile hormone analogs. ... 

Polymeric micropsheres, particularly those prepared from the biodegradable polylactide/ polyglycolide polymers, have been widely investigated as a means to achieve sustained parenteral drug delivery. The advantage of formulating the polymeric matrix as microspheres is the ability to administer them via a conventional needle and syringe as a suspension formulation, rather than as an implant (see below). Lupron depot formulations are available which can provide therapeutic blood levels of leuprolide acetate for up to four months. These products are presented as lyophilized polylactic acid microspheres which are reconstituted to form a suspension prior to administration. 

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