A validated stability-indicating method for simultaneous analysis of mevastatin and pravastatin in fermentation broth during bioconversion by Actinomadura macra

A simple, accurate, selective, precise, economical, and stability-indicating high-performance thin-layer chromatographic method for simultaneous analysis of mevastatin and pravastatin in fermentation broth has been established and validated. Compounds were separated on aluminium foil TLC plates precoated with silica gel 60F254; the mobile phase was toluene-ethyl acetate-formic acid 3:2:1 (v/v), which gave compact bands of mevastatin and pravastatin (RF 0.48 ± 0.02 and 0.31 ± 0.02, respectively). Detection at 237 nm resulted in r = 0.992 and 0.995 for mevastatin and r = 0.995 and 0.994 for pravastatin, for peak height and peak area, respectively. The limits of detection and quantification for mevastatin were 20.1 and 60.8 ng per band, and for pravastatin 19.2 and 58.3 ng per band, respectively. The method enabled effective quantification of mevastatin and pravastatin in the fermentation broth of Actinomadura macra and can therefore be used as a stability-indicating method for routine analysis of these compounds during bioconversion.