Biodegradable polymeric particles encapsulating an active agent, pharmaceutical compositions and uses thereof

Abstract

Therapeutic or prophylactic compositions providing an active agent, such as an antigen or a vector that contains and expresses an antigen, encapsulated in or incorporated into a biodegradable polymeric particle are provided. The compositions can also provide an active agent that is not encapsulated in or incorporated into the biodegradable polymeric particle in order to provide an initial or prime delivery of the active agent. Particles or composites providing an active agent encapsulated by a first and second polymer are also provided, wherein polymers are distributed in a gradient from a core of the composite to a surface of the composite, and configured to provide a delayed release of the active agent by a period of 7 days to 6 months. Methods of producing composites are also provided. Pharmaceutical formulations providing a single dose composition are also provided, along with methods for administering the pharmaceutical compositions to a subject in need thereof a therapeutically effective amount of an active agent are provided.

What is claimed is: 
     
         1 . A pharmaceutical composition comprising:
 a) a biodegradable polymeric composite particle comprising:
 (i) an active agent encapsulated by a first and second polymer, wherein the first and second polymer are distributed in a gradient from a core of the composite to a surface of the composite, wherein the first polymer has a higher concentration in the core than the surface and the second polymer has a higher concentration at the surface than the core, wherein the first polymer binds the second polymer via hydrogen bonding, and wherein the second polymer is configured to provide a delayed release of the active agent by a period of 7 days to 6 months; 
 (ii) an active agent encapsulated in a core by a first polymer, wherein the first polymer is a hydrophobic polymer and a shell comprising a second polymer, wherein the shell is configured to provide a delayed release of the active agent by a period of 7 days to 6 months; or 
 (iii) an active agent encapsulated in a hollow or aqueous core by a shell comprising a mixture of a first polymer, wherein the first polymer is a hydrophobic polymer, and a second polymer, wherein the shell is configured to provide a delayed release of the active agent by a period of 7 days to 6 months; and 
   b) a vaccine or therapeutic composition that is not encapsulated or stabilized with a polymer.   
     
     
         2 . A method for delivering an initial prime dose and delayed boost dose in a single administration dose, comprising:
 administering the pharmaceutical composition of  claim 1  to an animal in need thereof.   
     
     
         3 . A method for delivering a vaccine to a neo-natal animal, comprising:
 administering the pharmaceutical composition of  claim 1  to a neo-natal animal wherein the active agent is a vaccine composition and the particle comprises at least one coating comprising at least the second polymer configured for at least a first and second delayed release of the vaccine composition during ae period of 7 days to 6 weeks.   
     
     
         4 . The method of  claim 3 , wherein the second delayed release of the vaccine is at least 7 days after the first delayed release.