Viscous suspensions of controlled-release drug particles

Abstract

Controlled-release particles containing biologically effective agents such as therapeutic drugs and local anesthetics are suspended in a liquid suspending vehicle which has an elevated viscosity, the viscosity being substantially higher than that of water. Preferred vehicles are non-aqueous liquids and aqueous media which contain a dissolved polymer to increase the viscosity of the vehicle. Regardless of the composition of the media, however, the increased viscosity permits the use of particles of a relatively large size without a loss of suspension stability or localized application. The large particles offer the advantage of a longer release profile, and thus more prolonged activity of the agent.

Dependencies are inferred from the claim text.