The Positive Impact of an Extended Intervention on Dosing Accuracy of Student Compounded Suspensions

Objective. To demonstrate the impact of an extended intervention on the dose accuracy and consistency of a compounded zonisamide suspension. Methods. A laboratory exercise was initially conducted by pharmacy students to determine the beyond-use date (BUD) of a compounded zonisamide suspension. The student results were inconsistent with data in a published reference study. The exercise was repeated several times testing various hypotheses to explain the inconsistency. The final hypothesis was the student techniques of shaking and sampling their suspensions resulted in inaccurate samples. Therefore, a final hypothesis study was designed to include an extended intervention (weeks 5-7) that would demonstrate the impact of explicit verbal and visual instructions on the proper shaking and sampling of suspensions on dose accuracy and consistency. Results. The initial study found that students' weekly average zonisamide potencies ranged from 71%-122% of label, with a relative standard deviation (RSD) of 17%-53%; weekly potencies in the reference study had ranged from 92%-105%. In the final hypothesis study before the extended intervention, dosing accuracy ranged from 64%-111% (RSD 17%-76%). During the 3 week long intervention, dosing accuracy became 91%-118% with a RSD of 5%-29% which were consistent with the reference study. Conclusion. Providing more explicit auditory and visual instructions to pharmacy students regarding the proper shaking and sampling techniques of their compounded suspensions resulted in more consistent and accurate dosing of a zonisamide suspension. By implication, pharmacists providing specific and personalized instructions to patients should reduce their self-dosing inconsistencies at home.