Improved aerodynamically light particles for
drug delivery to the pulmonary
system, and methods for their synthesis and administration are provided. In a preferred embodiment, the aerodynamically light particles are made of a biodegradable material and have a tap density less than 0.4 g / cm3 and a
mass mean diameter between 5 mum and 30 mum. The particles may be formed of biodegradable materials such as biodegradable polymers. For example, the particles may be formed of a functionalized
polyester graft
copolymer consisting of a linear alpha-hydroxy-acid
polyester backbone having at least one
amino acid group incorporated therein and at least one poly(
amino acid)
side chain extending from an
amino acid group in the
polyester backbone. In one embodiment, aerodynamically light particles having a large
mean diameter, for example greater than 5 mum, can be used for enhanced delivery of a therapeutic agent to the alveolar region of the
lung. The aerodynamically light particles incorporating a therapeutic agent may be effectively aerosolized for administration to the
respiratory tract to permit systemic or local delivery of wide variety of therapeutic agents.