GMP Compliance Series: Part 5: Improving Quality through In-Process Control

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GMP Compliance Series: Part 5: Improving Quality through In-Process Control

Problems with In-Process Control
A dietary supplement manufacture,Health One Pharmaceuticals, Inc. received a warning letter in part because they did not establish in-process specification in their Master Manufacturing Record. This firm checked the weight of capsules throughout manufacturing, but they did not have an in-process specification. Thus, they wouldn’t know if that weight specification was met. The FDA was concerned that capsule weights can affect both the strength and composition of the finished product and this was not being properly controlled.

Vitaganic Inc. received a warning letter that contained a similar observation. Their manufacturing procedure for blending raw materials lists an in-process specification for a certain number of minutes in their Shaker-Mixer. When the FDA investigators asked how this was determined as the blending time to homogenize all mixtures, the firm did not provide data to support their specification. Thus, they did not know what impact a variation in blending times from batch to batch would have on their final product.

Why In-Process Controls are Important:

It is impractical to do final testing on many dietary supplements products. Meeting the in-process specifications, in combination with meeting component specifications, will help ensure that the final product specifications are met and that the product produced has the correct identity, purity, strength, and composition. It also reduces the risk that the dietary supplement will wind up with a contamination that may adulterate the finished batch. Since most dietary supplements are not required to have full end product testing for each and every ingredient, proper inspection of incoming materials and ingredients, and using good in-process specifications are the only way to ensure complete product quality and purity.

How to improve GMP compliance:

If you haven’t already, implement a process controls system. A process control system covers all stages of manufacturing, packaging, labeling, and holding. It makes sure the quality of the dietary supplement and that the dietary supplement is packaged and labeled as specified in the master manufacturing record. The first step in ensuring safe, high quality products is to use high quality components that meet well-defined specifications. It is best to test the materials before being used in a product rather than risk making an adulterated product or contaminating manufacturing equipment.

Monitor the steps where control is necessary to ensure quality. Production Controls are controls on in-coming components and dietary ingredients. This could include the use of a certificate of analysis from a qualified supplier for specifications other than the identity of a dietary ingredient. The identity of each component must be confirmed prior to use. Other required specifications for components must be checked either by relying upon a certificate of analysis or by testing or examining the component.

Determine whether in-process specifications are met. In-process specifications have to be set for any step or place in the manufacturing process where in-process control is needed. These might include heating, cooling or blending steps or product formulation steps. They might also include points where a specific sanitation procedure is needed, where cross-contamination may occur, or where employee and environmental hygiene are necessary to ensure quality.

Detect any deviation or unanticipated occurrence that may result in a failure to meet specifications. GMP regulations require you to review the results of any deviation or unanticipated occurrence that could result in adulteration. The deviation should be noted in the batch production record along with documentation that describes your investigation into the cause of the deviation or the unanticipated occurrence. Quality must conduct a material review and make a disposition decision if there is such an unanticipated occurrence during manufacturing. If you want to reprocess a batch with a deviation, Quality must review and give approval.


In-Process controls are important in any dietary supplement manufacturing operation. They are used to control all critical steps in the process and to prevent the failure of the final product. They reduce the risk of contamination or other factors that might lead to an adulterated product. Most importantly they ensures that the finished batch meets its requirement for identity, purity, strength and composition.