Fig. 4
1H NMR spectra of simvastatin (A) and the chloroform extract from the co-suspension of SS and MG (B). The spectra were measured in CDCl3. The chloroform extract was found to mainly contain the degradation product, simvastatin acid, with a small amount of the unchanged simvastatin (with asterisk). The spectrum (B) was considered to also contain some signals due to the additives of formulations. The numeric characters on the spectra (A) and (B) show assignments of the signals to the positions of the chemical structures shown in Fig. 1 (simvastatin) and Fig. 5 (simvastatin acid), respectively