Misuse preventative, controlled release formulation

Abstract

Disclosed is a misuse preventative, controlled release formulation comprising a core comprising a superabsorbent material (for example, polycarbophil), a controlled release coat surrounding the core, and a plurality of controlled release microparticles having a pharmaceutically active agent (for example, an opioid analgesic) disposed within the core, the coat, or both the core and the coat. When crushed, either intentionally or accidentally, and exposed to an aqueous medium, the superabsorbent material present in the coreswells to encapsulate the microparticles, which remain substantially intact thereby retarding the release of the pharmaceutically active agent from the formulation. Also disclosed is a method of using the misuse preventative, controlled release formulation to deliver a pharmaceutically active agent to a mammal, for example, a human, in need thereof.

1 . A solid, compressed controlled release formulation, comprising:
 (a) a core comprising a superabsorbent material comprising a cross-linked acrylic acid polymer characterized in that the cross-linked acrylic acid polymer absorbs at least 15 times its own weight of water, the superabsorbent material comprising from 30% to 70% (w/w) of the core;   (b) a controlled release coat surrounding the core; and   (c) a plurality of controlled release microparticles having a pharmaceutically active agent disposed therein, wherein the microparticles are disposed within the core, the coat, or both the core and the coat, the formulation having a hardness from about 200 N to about 400 N, and wherein the formulation
 (i) when intact and exposed to an aqueous medium, the pharmaceutically active agent is released from the formulation over a prolonged period of time, 
 (ii) when crushed to break the controlled release coat and exposed to 2 mL of water, the superabsorbent material absorbs all of the water and creates a hard gel that traps the microparticles, whereupon the hard gel and the microparticles provide controlled release of the pharmaceutically active agent disposed within the microparticles, and 
 (iii) when broken and exposed to 900 mL of water in a U.S.P. Type I Apparatus with stirring at 100 rpm for 30 minutes at 37° C., less than about 50% by weight of the pharmaceutically active agent originally present in the formulation before it was broken is released into the water. 
   
     
     
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