Determination of Drug Polymorphs by Laser Raman Spectroscopy. I. Ampicillin and Griseofulvin

Abstract
Raman spectroscopy of the lattice vibrations (phonons) is used to distinguish among various crystal forms of ampicillin and griseofulvin. The two anhydrous polymorphs of ampicillin and the trihydrate are all distinguishable. Griseofulvin sol-vates with benzene and chloroform were studied. The spectra suggest that the griseofulvin lattice structure expands to accept chloroform, but that the benzene solvate has a different crystal structure.