Abstract
The possible interaction of anhydrous ampicillin and ampicillin trihydrate with anhydrous dextrose, in the solid state, was investigated by comparing the thermal behavior, using differential scanning calorimetry, of physical mixtures of the respective original components in different molar ratios. Anhydrous dextrose was found to form complexes with anhydrous ampicillin and ampicillin trihydrate. These complexes were found to be dependent on the molar ratios of the mixture components. The stoichiometries of these complexes were determined from the enthalpy change of the DSC transitions of the mixtures and were found to be 1:1, 2:3 and 1:3 molar complexes between ampicillin, anhydrous and trihydrate, and anhydrous dextrose. Complexed ampicillin was found to decompose at markedly lower temperatures than uncomplexed ampicillin.