Active pharmaceutical ingredient. During the development of a new drug, pharmaceutical companies monitor the drug’s active pharmaceutical ingredient (API). An article published in Organic Process Research & Development (July 2013) demonstrated the use of an individual control chart (x-chart) for this purpose. The data in the table represent API values for 53 consecutive batches of the new drug. [Note: Read across rows for consecutive API measurements.] A StatCrunch printout with descriptive statistics for the data follows.

a. Locate the mean and standard deviation of the sample data on the printout.

b. Use the mean and standard deviation to find the center line and the upper and lower control limits for an x-chart of the data, as in Example 13.3 (p. 13-15).

c. Plot the data in an x-chart. Is the process in control? 100.8 100.8 101.5 101.5 101.5 101.3 100.9 100.6 100.6 100.4 100.8 100.1 100.7 100.4 100.4 100.3 98.9 100.3 100.3 100.3 100.3 100.2 100.8 100.8 99.5 100.7 100.4 100.4 100.8 100.7 100.7 100.4 100.0 100.3 100.7 100.7 100.7 100.6 100.0 100.7 100.8 100.3 100.3 100.9 100.5 100.5 101.2 100.6 100.7 100.6 101.1 101.0 101.1 Source: Based on K. Mukundam et al., “I-MR Control Chart: A Tool for Judging the Health of the Current Manufacturing Process of an API and for Setting the Trial Control Limits in Phase I of the Process Improvement,” Organic Process Research & Development, Vol. 17, July 2013 (Table 3).