Misuse preventative, controlled release formulation

Abstract

Disclosed is a misuse preventative, controlled release composition in the form of a multilayered oral dosage form. A first layer contains a plurality of controlled release microparticles having a pharmaceutically active agent (for example, an opioid analgesic) disposed therein. A second layer comprises a pharmaceutically active agent that can be the same or different from the pharmaceutically active agent in the microparticles. The composition further comprises a superabsorbent material disposed within the first layer, the second layer, or both the first layer and the second layer. When crushed, either intentionally or accidentally, and exposed to an aqueous medium, the superabsorbent material swells to encapsulate the microparticles, which remain substantially intact thereby retarding the release of the pharmaceutically active agent from the composition.

1 . A solid, compressed controlled release composition for oral administration of at least one pharmaceutically active agent, comprising:
 (a) a first layer comprising a first population of controlled release microparticles having a pharmaceutically active agent disposed therein;   (b) a second layer comprising a pharmaceutically active agent disposed therein, wherein the second layer is adjacent the first layer;   (c) 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, wherein the superabsorbent material is disposed within the first layer, the second layer, or both the first layer and the second layer, wherein the superabsorbent material comprises from about 10% to about 50% w/w of at least one layer containing the superabsorbent material;   (d) a controlled release agent disposed within the first layer, the second layer, or both the first layer and the second layer; and   (e) the composition having a hardness from about 200 N to about 400 N, and wherein the composition,
 (i) when intact and exposed to an aqueous medium, the pharmaceutically active agent disposed in the second layer is initially released at a faster rate than the pharmaceutically active agent disposed in the first layer, 
 (ii) when crushed 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. 
   
     
     
         2 - 40 . (canceled)