Use of alkyl cellulose as controlled release matrix material in alcohol resistant dosage forms

The disclosure relates to the use of an alkyl cellulose, particularly ethyl cellulose, as controlled release matrix material in the manufacture of an opioid salt controlled release matrix formulation to impart resistance to alcohol extraction of the opioid salt; wherein the alkyl cellulose is used in an amount from 5 to 60 % (by wt.) of the matrix formulation; and wherein less than 25 % of the opioid salt is released after 1 hour of in-vitro dissolution of a dosage form comprising said formulation in 500 ml, or 900 ml of Simulated Gastric Fluid with 20 % ethanol using USP Apparatus I (basket) operating at 100 rpm at 37 Deg. C. A controlled release dosage form comprising an opioid analgesic salt and a controlled release material comprising alkyl cellulose, particularly ethyl cellulose, is also disclosed,wherein the alkyl cellulose is used in an amount from 5 to 60 % (by wt.) of the dosage form; and wherein the ratio of the amount of opioid analgesic salt released after 1 hour of in-vitro dissolution of the dosage form in 500 ml, or 900 ml of Simulated Gastric Fluid with 20% ethanol using a USP Apparatus I (basket) apparatus at 100 rpm at 37 degrees Celsius to the amount of opioid analgesic salt released after 1 hour of in-vitro dissolution of the dosage form in 500 ml, or 900 ml, respectively, of Simulated Gastric Fluid with 0% ethanol using a USP Apparatus I (basket) apparatus at 100 rpm at 37 degrees C is less than about 2:1.