Possibilities of preparation and storage of standard histamine solutions

Abstract

Background. To explore the stability of histamine solutions of low concentrations sterilized by autoclaving and filtration as well as the possibilities of storage and use of these solutions after 1-fold and 5-fold freezing and defrosting. Methods. Histamine dihydrochloride solutions at a concentration of 10 μg/ml were sterilized by the membrane filtration or the autoclaving at 121 °C for 30 minutes. The solutions were frozen in sterile insulin syringes, followed by 1- and 5-fold defrosting. Skin prick tests have been performed with the resulting solutions. Results. When comparing the results of skin prick testing performed with autoclaved and sterilized by the filtration histamine, no statistically significant differences were found (p>0,05). Comparison of the results of skin prick tests performed with histamine that hadn't been frozen before, after 1- and 5-fold freezing and defrosting showed no statistically significant differences (p>0,05). Conclusion. It has been shown that histamine solutions sterilized by autoclaving at 121 °C for 30 minutes followed by repeated freezing and defrosting don’t change their biological activity substantially.