Stabilized sustained release tramadol formulations

摘要

A stabilized sustained release oral solid dosage form which includes an effective amount of tramadol or a pharmaceutically acceptable salt thereof dispersed in a matrix of a hydrophobic material comprising a wax-like substance which was melted or softened during the preparation of the matrix, is cured at a temperature from about 35° C. to about 65° C. for a time period from about 4 to about 72 hours, such that the formulation, when subjected to in-vitro dissolution after exposure to accelerated storage conditions of at least one month at 40° C./75% RH, releases an amount of tramadol which does not vary at any given dissolution time point by more than about 20% of the total amount of tramadol released when compared to in-vitro dissolution conducted prior to subjecting the dosage form to the accelerated storage conditions.