Stability of carmustine--kinetics and compatibility during administration
Fredriksson, K.; Lundgren, P.; Landersjö, L.
Acta Pharmaceutica Suecica 23(2): 115-124
1986
ISSN/ISBN: 0001-6675 PMID: 3739737 Document Number: 281760
Factors affecting the stability of carmustine in aqueous solution were investigated at 25.degree. C. The degradation of carmustine in citrate buffers was studied over the pH range 2.8-7.3. Maximal stability was obtained between pH 3.3-4.8, corresponding to a t10% value of 5.5 h. The influence of light on the decomposition was studied in a light cabinet with an illumination intensity ranging from 500-4000 lux. The degradation rate increased with increasing illumination intensity. There was a linear relationship between the logarithm of the reaction rate constant and the illumination (lx). The activation energies in light and darkness were determined at 64.5 kJ/mol and 93.4 kJ/mol, respectively. Sorption behaviour of carmustine was found to be dependent on the plastic material of the infusion set. Also, the infusion fluid rate influenced the loss of carmustine. Considerable loss may occur at slow infusion rates.