Syringeability of morphine ARER, a novel, abuse-deterrent, extended-release morphine formulation

Background: Extended-release (ER) morphine formulations are commonly manipulated for non-oral routes of administration, particularly via injection. Morphine ARER, an abuse-deterrent formulation of ER morphine, has both physical and chemical properties that deter abuse. Objectives: To assess the syringeability of morphine ARER using in vitro laboratory studies. Methods: Intact, cut, or crushed morphine ARER tablets were incubated in 1, 5, or 10 mL of room temperature or 90°C water for 1, 5, 10, or 30 min of agitation. Crushed ER morphine tablets were assessed in 10 mL room temperature water. The difficulty to draw the mixture into a syringe was assessed on a scale of 1 (very easy) to 10 (impossible). If the prepared mixture was syringeable, released morphine was measured analytically. Results: Crushed and cut morphine ARER tablets formed a viscous material when subjected to a liquid environment and were rated as "impossible to syringe" in ≤5 mL water and were slightly syringeable in 10 mL water. In contrast, all syringeability tests of crushed ER morphine were rated as "very easy to syringe". After 30 min in room temperature water, crushed ER morphine released 75% morphine whereas intact, cut, and crushed morphine ARER tablets released a maximum of 12%, 12%, and 5% of the total morphine content. Heating extractions resulted in increased morphine release. Conclusion: The difficulty to syringe morphine ARER when manipulated suggests that morphine ARER has abuse-deterrent properties that may deter intravenous abuse.