SUMMARY
One of the main objectives for drug manufacturers is to study stability, which is the quality factor for any drug. The requirements of stability are imposed to the extemporaneous medicines too. The Guide for the Compounding Practitioner (USA) contains article “1191” “Stability considerations in dispensing practice” with recommendations to repacking of substances, which can be used in pharmaceutical compounding. The pharmacy receives the wool fat substance in the original packing with a large volume that causes the necessity of its opening and the substance repacking to the container of a smaller volume for direct use. The analysis of the wool fat substance stability under conditions of its repacking from original packing to the amber glass container during the research has been done. The research has shown its compliance with the parameters set. The repacked substance was stored at the temperature of + 25°C in the pharmacy conditions in the assistant room within four months. Re-analysis of the quality parameters indicates the compliance with the requirements of the “Quality control methods” (QCM) and the European Pharmacopoeia. It has been found that the acid and peroxide values have increased only a little, and the water absorption ability of the substance has decreased. The results obtained have shown that all quality parameters of the wool fat substance in relation to stability when storing in the pharmacy after its repacking from original packing to the amber glass container are preserved within four months.