Physicochemical stability of carboplatin solutions in 5% glucose stored in polypropylene syringe for skin tests

This study aimed to evaluate the physicochemical stability of highly diluted carboplatin solutions (1, 0.1, and 0.01mg/mL) in 5% glucose, stored in polypropylene syringes at different temperatures.

The stability protocol was developed in accordance with International Council for Harmonisation guidelines. Carboplatin dilutions were aseptically prepared and stored protected from light at 5±3°C and 25±2°C. Samples were analyzed in triplicate from three syringes per condition on days 1, 2, 3, 4, 7, 10, 14, 21, and 28. A validated, stability-indicating ultra-high-performance liquid chromatography method coupled with a photodiode array detector was used for concentration monitoring. Forced degradation studies were conducted to identify potential degradation products. Physical parameters including color, clarity, visible particles, precipitation, and pH, were also assessed.

All samples retained more than 95% of their initial concentration over the 28-day study period under both temperature conditions. No degradation products were detected on chromatograms, and no significant changes in physical parameters were observed.

Carboplatin solutions diluted in 5% glucose and stored in polypropylene syringes remain chemically and physically stable for at least 28 days at both refrigerated and room temperature when protected from light. These findings support the feasibility of advance preparation of diluted carboplatin for use in allergy testing, offering potential operational benefits for centralized pharmacy units.