Stability of reconstituted indomethacin sodium trihydrate in original vials and polypropylene syringes

Abstract

The stability of reconstituted indomethacin sodium trihydrate 0.5 mg/mL in sterile water for injection for 14 days at either 2-6 °C or room temperature (21-25 °C) in the drug's original vial and in polypropylene syringes was studied. Twenty 1-mg vials of indomethacin sodium trihydrate were reconstituted with 2 mL of Sterile Water for Injection, USP. Solution from 10 vials was drawn into 20 1-mL disposable polypropylene syringes. Five vials and 10 syringes were stored at 21-25 °C, and the other 5 vials and 10 syringes were stored at 2-6 °C. Samples were taken on days 0, 1, 2, 4, 5, 7, 9, 12, and 14 and analyzed by liquid chromatography. Physical inspections and pH determinations were made as well. Throughout the study period, all solutions stored at 2-6 °C retained more than 95% of the initial indomethacin concentration. At room temperature, solutions stored in syringes retained more than 95% of the initial indomethacin concentration. Solutions stored in glass vials contained only 89.7% of the initial concentration on day 14. Solutions stored at room temperature in either syringes or vials had greater amounts of degradation products than solutions stored at 2-6 °C. Reconstituted indomethacin sodium trihydrate 0.5 mg/mL was stable for 14 days when stored in polypropylene syringes at 2-6 or 21-25 °C and in its original glass vials at 2-6 °C. When stored in the glass vials at 21-25 °C, the reconstituted drug was stable for 12 days.