STABILIZATION OF ACETAMINOPHEN IN AQUEOUS SOLUTION

Stable pharmaceutical solution comprising acetaminophen and method of making such are provided. The pharmaceutical solution includes: an aqueous solution comprising acetaminophen; a solubilizing effective amount of a solubilizer, a weak organic acid having a having a having a COOH group and pKa greater than 3. The weak acid is in a sufficient amount to achieve and maintain the pharmaceutical solution at a pH from about 3.8 up to 6.61 for stability of acetaminophen and maintain effectiveness of the preservative. The method of making a stable pharmaceutical solution comprising acetaminophen includes: mixing water, acetaminophen, a solubilizing effective amount of a solubilizer, and a weak organic acid having a having a COOH group and pKa greater than 3 in a sufficient amount to form and maintain the solution at a pH from about 3.8 up to 6.61 for stability of acetaminophen.