What is continued process verification (CPV), and how does it differ from continuous and ongoing process verification?

1Three terms, two ideas.

The terms differ by jurisdiction and by purpose. Two of them name the same lifecycle activity; the third is a way of validating a process in the first place.

Watch the abbreviation. FDA’s guidance spells out continued process verification and doesn’t abbreviate it.¹ In PIC/S’s recommendations on qualification and validation, revised as PI 006-4 from 1 October 2026, CPV means continuous process verification and OPV means ongoing (or continued) process verification.⁴ Check which one a document means before comparing them.

2What continued, or ongoing, process verification requires.

FDA’s process validation guidance of January 2011 describes three stages: process design, process qualification, and continued process verification, in which “ongoing assurance is gained during routine production that the process remains in a state of control”.¹ It rests on 21 CFR 211.180(e), which requires records to be kept so their data can be used for evaluating, at least annually, the quality standards of each drug product.⁵ FDA reads this as requiring “an ongoing program to collect and analyze product and process data that relate to product quality”.¹

FDA’s recommendations for Stage 3 include:

• data on process trends and on the quality of incoming materials, in-process material and finished product, statistically trended and reviewed by trained personnel;
• a data collection plan and statistical methods developed by a statistician or someone trained in statistical process control, with procedures that guard against overreacting to individual events and against missing unintended variability;
• scrutiny of intra-batch as well as inter-batch variation;
• monitoring and sampling at the level set during process qualification until there is enough data for significant variability estimates, then adjusting to a statistically appropriate level;
• signals from complaints, out-of-specification findings, deviations, yield variations and adverse event reports, and periodic meetings between the quality unit and production.¹

In the EU, Annex 15 applies ongoing process verification to every process, whether it was validated traditionally, by continuous process verification or by a hybrid. Manufacturers monitor product quality and evaluate process trends, review the extent and frequency of monitoring periodically, work under an approved protocol or equivalent with a report, and use statistical tools where appropriate. The results support the product’s validated status as documented in the product quality review.² PI 006-4 adds that ongoing verification should start after initial validation and continue until the product is discontinued, that it “has taken the place of periodic revalidation”, and that results should be reported at an interval set by risk that “normally should not exceed one year”, using statistical tools such as Cpk and Ppk wherever possible.⁴

3What continuous process verification is.

Continuous process verification replaces, or supplements, the traditional set of validation batches. ICH Q8(R2) defines it,³ and Annex 15 allows it “as an alternative to traditional process validation” for products developed by a quality by design approach, where development has shown that the control strategy gives a high degree of assurance of product quality. The verification method has to be defined, with a science-based control strategy for incoming materials, critical quality attributes and critical process parameters; process analytical technology and multivariate statistical process control may be used. The manufacturer still justifies the number of batches needed.²

EMA’s guideline on process validation for finished products, revised in November 2016, says continuous process verification “can be used in addition to, or instead of, traditional process validation” and can be introduced at any point in the product’s lifecycle. The dossier should discuss the strategy, supported by at least laboratory or pilot scale data, and EMA considers it “the most appropriate method for validating continuous processes”.⁶ PI 006-4 notes that this approach may need prior approval from the competent authority.⁴

A hybrid of the two is possible. Annex 15 allows it where there is substantial product and process knowledge from manufacturing experience and historical batch data, including for validation after changes to a product first validated traditionally.²

4How they fit together.

EMA’s guideline places the stages the same way: process design falls under ICH Q8(R2), validation of the manufacturing process under the guideline itself, and “the third stage (on-going process verification) is covered under GMP (Annex 15)”.⁶ EU GMP Chapter 1 asks for product quality reviews, normally annual, with the objective of “verifying the consistency of the existing process”,⁷ and ICH Q10 expects a monitoring system for process performance and product quality “to ensure a state of control is maintained”.⁸ PI 006-4 recommends designing ongoing verification reports so that the product quality review can reference them.⁴

5How it runs in Seal.

Seal’s continued process verification blueprint draws trends from the same records the batches and tests ran in, so they stay connected to the batches, process versions, methods and materials behind them. Pending and non-comparable results stay visible outside the analysis, a signal becomes a record with its own review, and the evidence carries into investigation, change control and the annual product quality review. After an approved change, later batches form a new cohort.

Neil prepares the population, calculations and a draft review; for process capability it checks population stability, specification versions and measurement context first, and a qualified reviewer decides the statistical approach. The process validation blueprint carries the controls and residual risks reviewed during PPQ into that monitoring.