Investigation Of The Effects Of Excess Ethylenediamine On The Chemical Stability Of Aminophylline Injections

Abstract

Aminophylline injections contain theophylline combined with ethylenediamine in a 2:1 ration and the injections are used for various purposes

(9, 10, 12) - The official compedia specify the addition of ethylendiamine in excess of that required to form the aminophylline. This is supposedly to ensure that any slight carbon dioxide absorption does not precipitate theophilline which is only slightly/(15). A / soluble farther role to that is that the excess ethyl enerii amine could in fact • chemically stabilise the aminopylline, that is decrease chemical degradition of aminophylline. This project was an investigation of that possible role. Aminophilline injections were assayed '^determine both the quantities of ethylendiamine and theopylline and hence the content of excess ethylenediamine. The assay included solutions made in 0.01N NaOH and in boratebuffer and percentage recovery determined. The various theophylline solutions including the injections were examined by thin layer chromatography (TLC). Differential spectroscopy work was also carried out and finally the degradation kinetics at boiling point of water (94.60 C ; of pure theophylline and the aminopylline injections studied.