FREE RADICAL FORMATION IN ROSUVASTATIN DURING THERMAL STERILIZATION AT DIFFERENT TEMPERATURES.

Rosuvastatin was thermally sterilized at temperatures 160⁰C during 120 min, 170⁰C during 60 min and 180⁰C during 30 min, according to Polish pharmacopoeia norms. Free radicals formed in the heated rosuvastatin samples were examined by electron paramagnetic resonance (EPR) spectroscopy. The best conditions of thermal sterilization of rosuvastatin were searched. EPR spectra were measured for the analyzed drug independent on heating temperature. Decrease of free radical concentrations in rosuvastatin with increasing of heating temperature was stated. The optimal conditions for thermal sterilization of rosuvastatin were temperature 180⁰C and heating time of 30 min and resulted in the lowest free radical concentration. The changes of amplitudes (A) and linewidths (∇Bpp) of EPR spectra of the heated rosuvastatin were characteristic for homogeneous broadening EPR lines. Slow spin-lattice relaxation processes existed in the all rosuvastatin samples. The confirmation of usefulness of electron paramagnetic resonance spectroscopy in pharmacy was presented.