Potency Analyses Provide Insight Into Student Aseptic Compounding Technique Errors.

Objective. To determine whether direct observational scores were predictive of the potency of pharmacy students' compounded sterile preparations (CSPs) and to identify any misunderstandings students had regarding individual aseptic technique steps. Methods. P1 students performed aseptic techniques during three observational encounters separated by two weeks. Students' performances were evaluated using an observation-based rubric and were subject to potency analysis. The encounters were transferring a drug solution from a vial, an ampule, and a reconstituted powder to intravenous (IV) bags. Results. The mean potency of the diphenhydramine (vial) and lidocaine (ampule) met the ±10% goal of expected potency. These results were significantly different from those of the ampicillin (reconstitution) encounter, which was outside the goal. The percentage of students meeting the potency goal was 59.3% for the diphenhydramine, 80.3% for the lidocaine, and 50.4% for the ampicillin encounters. The observation scores were significantly different between all three encounters. There were no correlations between the observational scores and the potency for any encounter regardless of whether or not the student met the goal potency. Although their observation scores were acceptable, up to 50% of students did not meet the potency goal for each of the three encounters. Conclusion. The potency data provided the critical insight that P1 students were not adequately trained to account for pressurization when manipulating vials using aseptic compounding processes. The results suggest that both observation scores and potency analysis should be part of an overall assessment of student ability to compound sterile preparations.