Determination of mevalonolactone in capsules by capillary gas-liquid chromatography.

A wide bore capillary gas chromatographic method was developed to determine mevalonolactone in capsule formulations. The method uses beta,beta-dimethyl-gamma-hydroxymethyl-gamma- butyrolactone as an internal standard and has been validated for its accuracy, precision and linearity. The method has been applied for stability testing of the capsule formulation. High-performance liquid chromatographic and gas chromatographic studies demonstrated cyclization of mevalonic acid (open-chain form) to mevalonolactone (cyclic form) under the described gas chromatography conditions. Mass spectrometric analysis indicated that mevalonolactone prepared in water or an organic solvent emerged from the gas chromatographic column as the intact cyclic lactone.