Exploring the Use of Ambientally Stored Methylene Diphosphonate Radiopharmaceutical Aliquots in Solving Challenging...

Objectives  The primary aim was to evaluate the prolonged quality characteristics of methyl diphosphonate (MDP) aliquots during ambient storage over a specified duration. This study further investigated potential additives that could enhance the stability of MDP aliquots stored under such conditions. Materials and Methods  This was a laboratory-based experimental study conducted at the University Teaching Adult Hospital in Lusaka, Zambia. A total of 36 MDP aliquots stored at ambient conditions and 4 MDP aliquots stored at conventional refrigerated frozen conditions were labeled with technitium-99m ( ^99m Tc) and tested for radiochemical purity (RCP) and other quality characteristics. A comparative analysis of the stability and quality of MDP aliquots from the two cohorts was then conducted. Statistical Analysis  Stata 14 was used to analyze the data on the RCP of all MDP aliquots. Results  The RCP of ambient stored MDP aliquots was found to be ranging from 98 to 99%, while that for frozen and refrigerated ones ranged from 99 to 100%. There was also a 1% increase in RCP for both cohorts with argon gas purging (98 and 99%, respectively). Conclusion  The RCP of MDP aliquots from both cohorts was much higher than the required minimum of 90% implying that there was no significant association of their stability and quality with the mode of storage. However, purging with argon gas seemed to increase the stability further in both streams. The study findings show potential for application in resource-constrained environments and centers, especially in developing countries, where challenges to maintain the cold storage chain of these important radiopharmaceuticals are likely to be encountered due to power outages.