By Robert G. McGregor, General Manager, Brookfield Engineering Laboratories, Inc.
The Pharmaceutical Industry typically employs the grab sample technique to evaluate viscosity behavior of material in process. High volume products like cough syrup and skin lotions for sun protection are good candidates for “in-process” viscosity measurement because payback for equipment investment can be justified. Products produced in limited quantity should continue with the grab sample approach.
Accomplishing a successful installation with the first in-line viscometer is very important for building confidence in your organization. Like any project that accomplishes something new in manufacturing, the person who heads up the project serves as the champion, i.e. the go-to person for all questions and problem resolution. This individual must prove to all that the expenditure is valid and that the on going operation delivers the returns that were projected at the start of the project.
Reviewing data for the grab sample measurements is the starting point. Products that exhibit a higher frequency of falling outside the viscosity pass/fail limits are among the first candidates to focus on. Next for consideration are those products that require more frequent testing due to either the complexity of the processing or the value of the material in production. Selecting a qualified product for going “on-line” assures a better chance of success. The investigation includes assessing how much time it takes to grab samples, make the viscosity measurements, process the data, and take corrective action when the test fails.