Stability of expired tropane alkaloid ampoules using HPLC-UV/CAD

Medicines often have a much longer shelf life than stated by the manufacturer. Due to the high costs of emergency stockpiling, but also due to supply shortages, an extended shelf life can offer many advantages. In this study, three injection solutions containing atropine, scopolamine and belladonna total alkaloids, respectively, manufactured between 1940 and 1960 and stored under uncontrolled conditions, were tested, to show that pharmaceutical products, containing tropane alkaloids, are significantly more stable than expected after some 80 years. To analyze the stability of the main alkaloids atropine and scopolamine, a method using charged aerosol detection (CAD) was developed and validated. CAD enables the detection of degradation products that lack a chromophore and cannot be detected using pharmacopoeial (UV) methods. For separation a SIELC Primesep 200 column (4.6 ×150 mm; 100 Å; 3 µm) and gradient elution with water, acetonitrile and formic acid were used. The results indicated a high stability of atropine, with a determined content of 101.9 % and a small amount of degradation products. Scopolamine, however, showed higher degree of degradation with a remaining content of 68 %.