Minimization of preventable drug waste through use of a vial combination calculator tool.

Purpose: This project aimed to determine whether a supportive calculator that automates the vial selection process might offer a practical and efficient method of reducing pharmaceutical expenditures through minimizing preventable drug waste in outpatient pharmacy settings.

Summary: Drug waste is a substantial target of cost-saving efforts in the areas of oncology and autoimmune therapy, which involve use of a vast number of high-cost medications packaged in single-dose vials of varying strength. To facilitate selection of the optimal combination of medication vials and thereby minimize preventable drug waste, a Microsoft Excel-based calculator was developed for use by staff of a large oncology pharmacy network. Twenty-three high-cost chemotherapy and monoclonal antibody medications were identified as initial targets for the drug waste prevention initiative. After dissemination and implementation of the calculator and provision of monthly pharmacy staff education, the dollar value of preventable drug waste and the number of suboptimal vial combination selections were reduced by 51% ($412,300) and 54% (315 selections), respectively, in fiscal year 2022 and further reduced by 46% ($183,400) and 27% (71 selections), respectively, in fiscal year 2023.

Conclusion: After implementation of an automated vial selection tool, preventable drug waste and the quantity of suboptimal vial combination selections were markedly reduced across 11 outpatient compounding pharmacies.