Assessment of the accuracy of pharmacy students' compounded solutions using vapor pressure osmometry

OBJECTIVE. To assess the effectiveness of using a vapor pressure osmometer to measure the accuracy of pharmacy students' compounding skills. DESIGN. Students calculated the theoretical osmotic pressure (mmol/kg) of a solution as a pre-laboratory exercise, compared their calculations with actual values, and then attempted to determine the cause of any errors found. ASSESSMENT. After the introduction of the vapor pressure osmometer, the first-time pass rate for solution compounding has varied from 85% to 100%. Approximately 85% of students surveyed reported that the instrument was valuable as a teaching tool because it objectively assessed their work and provided immediate formative assessment. CONCLUSIONS. This simple technique of measuring compounding accuracy using a vapor pressure osmometer allowed students to see the importance of quality control and assessment in practice for both pharmacists and technicians.