At higher concentration amoxicillin gave non first order degradation kinetics, indicative of dimerization reaction and the rate of dimerization of amoxicillin at pH 9 is greater than that of other aminopenicillins. Degradation of amoxicillin (sodium salt) at higher concentration became faster in the presence of carbohydrates (dextrose, dextran, and sorbitol) and alcohols. Amoxicillin showed a pH dependent stability with the stability increasing with decrease in pH