Chemical Engineering: Understanding The Curriculum For Quality Manufacturing

Chemical Engineers during their training are taught that they will commercialize and/or operate a process that will produce consistent quality product all the time (without re-work) using a safe, sustainable and an economic process.

To achieve these objectives, we review topics that teach us the understanding of the physical properties of material (raw material, intermediate, by-product and the product) involved in the process. This allows us to understand their interaction in a reactive and/or a blending process. Chem. E. uses this information to commercialize a robust process.

If we have mastered the properties and the interaction of chemicals involved, we should be able to define the operating conditions of a process having the highest yield with above defined process characteristics. We are also taught various unit operations that we can use as is, modify and/or manipulate to produce a quality product all the time. If we are not able to achieve the objective of producing quality product using a safe and sustainable process, the first time and all the time, we have to improve our understanding so that we can have the correct process.

If I translate the Chem. E. training fundamentals to acronyms, we are taught to develop and commercialize a QUALITY BY DESIGN (QBD) process. This is our "hippocratic oath". Anything short of this objective suggests that we need to improve.

Regulatory bodies have introduced few other acronyms in the pharmaceutical manufacturing. They are fine to have but what they mean and tell us is not totally understood. Interpretations of these vary and introduce variability. My question is: are we trying to have the best pharmaceutical manufacturing technology or are we trying to conform to the current fashion crowd?

My interpretation of QBA, CQA, CMC, DS, and PAT is as follows. If my understanding is not what the "guru's" expect it to be, then please help with the correct interpretation.

  • CQA [critical quality attributes]: We need to understand the physical properties of the materials (raw material, intermediate, by-product and the final product) and how they interact with each other.
  • DS [design space]: Definition of the process operating parameters that have been identified by the developers, which if followed will produce quality product all the time.
  • CMC [chemistry, manufacturing and controls]: Reaction mechanism, kinetics and process controls that is understood and followed will allow production of quality product. 
  • PAT [process analytical technologies]: This acronym is the least understood. It is believed that by having PAT, all of the process ills will go away. That is far from the truth. Analytical instruments will let the manufacturing and quality people know that the process has erred. However, it will not correct the problem and give a solution to the problem. Only people who are familiar with the characteristics of the materials and chemistry can correct the process. Analytical instruments are an indicator and not the corrector. There is difference between process control technologies and process analytical technologies.
  • QBA [quality by analysis]: It suggests that we have a problem and we do not meet quality. We have to go back and fix the problem so that we can produce the desired quality.

To summarize the above mentioned acronyms are the fundamentals of chemical engineering curriculum. If we understand pieces parts of the curriculum, then we should have a QBD process. Question then arises why it is so hard to implement the fundamentals of chemical engineering in the manufacture of a pharmaceutical (API or a blend of API and excipients) or did I miss something.

Girish Malhotra, PE
EPCOT International