Description  Claims  Drawing  Cited references 

US4176186A   [0003]  [0038] 
US4719215A   [0003] 
US4861781A   [0003] 
US5102887A   [0003] 
US5972954A   [0003] 
US6274591B   [0003] 
US5866154A   [0004] 

Remington's Pharmaceutical Sciences   [0061] 
Macromolecules   [0069]