Kinetics of drug degradation. Part 58: a method of preparation and the stability of 3% aqueous indometacin solution.

A method was worked out which allows one to obtain 3% aqueous indometacin solution. The above can be done by solubilization of indometacin by means of ethyl carbamate and ethylurea in the concentration of 30% each and boiling the mixture for 30 s. The stability of indometacin in the above solution was checked with respect to elevated temperatures and exaggerated UV light conditions and compared with the stability of the same solution but without the solubilizing agents. It appears that the solubilizing agents diminish both the hydrolytic as well as the photochemical degradation processes of indometacin. 3% aqueous indometacin solution is stable for 25 months at 20 degrees C, and it is practically non-susceptible to the effects of diffused light for many years. The indometacin solution proposed shows low acidity (pH = 6.95). It is believed that the above solution can be introduced to everyday medical treatment.