Influence of ethanol water-content on gatifloxacin recrystallisations

Gatifloxacin is a flouroquinolone anti-bacterial agent. This study proved that even the presence of small amounts of water in the recrystallisation medium influenced the product obtained. Different crystal forms were produced from various binary mixtures of ethanol and water. Where mixtures had a water content greater than (or equal to) 50% v/v, only hydrated crystal forms were produced and no ethanol was incorporated into the lattice.