When a 99% Pure Chemical Failed in API Production
A commercially sourced auxiliary chemical can meet a 99% purity specification and still fail in pharmaceutical production. A ChiroBlock project demonstrates why nominal purity alone may not reveal the quality attributes that determine application performance.
Quick answer: A headline purity value describes the total proportion assigned to the main compound. It does not necessarily identify critical impurities, process-related variations or material properties that can affect a sensitive application.
Why Did a 99% Pure Chemical Fail in API Production?
The auxiliary chemical had been commercially available for many years, carried an established CAS number and was supplied with a stated purity of 99%. Nevertheless, individual batches repeatedly performed differently when used in the customer’s API synthesis.
Standard certificates of analysis did not explain the variation. The decisive quality difference was therefore located outside the parameters routinely reported by the supplier.
This is an important distinction: chemical identity and nominal purity do not automatically demonstrate that a material is suitable for a specific production process. The relevant question is whether the attributes that influence the application have been identified, measured and controlled.
How Did ChiroBlock Investigate the Quality Gap?
ChiroBlock pursued three tasks in parallel:
- identify the supplier-dependent production parameter responsible for the variable performance;
- develop a method for reworking unsuitable material if the critical parameter could not be identified in time; and
- establish analytical methods capable of detecting low-performing material before release.
The project combined chemical analysis, experimental synthesis, purification and process development. This broader approach was necessary because analysis alone could describe differences between samples but could not automatically establish how the required material quality should be produced reliably.
Further information about translating application requirements into measurable chemical criteria is available on ChiroBlock’s page about custom synthesis to specification and reliable repeat supply.
How Was the API Supply Chain Secured?
ChiroBlock produced kilogram quantities of suitable material before the customer’s existing stock was depleted. In parallel, the newly developed and validated process was transferred to another contract manufacturer.
The customer ultimately established a more resilient supply chain with two independent sources, a robust and documented process, and knowledge of the critical parameters affecting material performance.
The compound discussed in this example was an auxiliary chemical used in API production. The case study does not describe cGMP manufacture of the API by ChiroBlock.
What Does This Case Demonstrate?
Reliable chemical supply requires more than the correct substance name, CAS number and nominal purity. For sensitive applications, the relevant quality attributes, analytical methods, production parameters and acceptance criteria must be understood together.
Depending on the starting point, this may require chemical process development and route redesign followed by quality-managed recurring manufacture.
Read the Complete Case Study
The full case study by Dr Oliver Seidelmann explains the initial supply problem, the three parallel development tasks, the chemical route and the establishment of two independent supply sources.