Drugdu.com expert's response:

When exporting Active Pharmaceutical Ingredients (APIs), overseas buyers often request suppliers to provide Certificates of Analysis (COA), product specifications, and GMP-related documentation. However, after initial communication, some customers will further ask for Stability Data to confirm the product's quality changes under different storage conditions.

This can sometimes pose a dilemma for suppliers. While enterprises can provide COAs for recent batches to prove that products meet quality standards at the time of release, buyers still demand long-term stability data, accelerated stability study results, and even inquire about the product's re-test period and storage conditions.

So why are stability data required even when a COA is already available? If an enterprise does not yet have a complete stability study report, will this affect subsequent procurement?

COA and Stability Data Demonstrate Different Quality Attributes

A COA (Certificate of Analysis) primarily indicates whether the test results of a specific batch of product comply with the specified quality standards. For example, the COA of an API may include test items such as description, identification, assay, related substances, water content, and residual solvents, helping buyers determine if the batch meets the corresponding specifications.

However, a COA generally reflects the quality status of a specific batch at a defined testing time point. It cannot independently prove that the product will still meet the established quality criteria after months or even longer storage.

For instance, an API may meet all specifications for assay, impurities, and moisture at the time of release, but changes may occur after prolonged storage due to factors like temperature, humidity, light exposure, or packaging conditions. For some APIs that are prone to degradation or sensitive to environmental factors, temperature fluctuations during storage and transportation may also impact product quality.

Therefore, when evaluating API suppliers, overseas pharmaceutical manufacturers need to understand how long the product can maintain its quality under specified storage conditions, in addition to confirming the test results of the current batch.

In accordance with the principles of ICH Q1A(R2), stability studies are required to evaluate the quality changes of active pharmaceutical ingredients under the influence of environmental factors such as temperature, humidity, and light, providing a basis for recommending storage conditions and re-test periods. For applicable products, evaluations should be carried out by combining long-term stability studies, accelerated stability studies, and necessary intermediate condition tests.

What Issues Are Buyers Usually Confirming by Requesting Stability Data?

For overseas pharmaceutical manufacturers that intend to use the API for pharmaceutical production, the raw materials will go through international transportation, warehousing, production scheduling, quality release, and other links after procurement.

Buyers need to know whether the product is stable under the storage conditions recommended by the supplier, whether the existing packaging is suitable for long-term storage, whether temperature changes during transportation may affect quality, and whether the labeled re-test period of the product is supported by corresponding research data.

For example, an overseas pharmaceutical company procures an API, and the supplier provides a COA that meets the quality standards, with a labeled re-test period of 24 months. The buyer's further request for stability data is mainly to confirm that this re-test period is based on sound research evidence, rather than merely determined based on the enterprise's experience.

Some customers also pay attention to the batches, packaging materials, testing time points, and critical quality indicators used in the stability studies. If there are significant differences between the packaging used for actual product supply and the packaging applied in the stability studies, buyers may need further confirmation on whether the existing data is still applicable.

For projects involving drug registration, the importance of stability data becomes even more prominent. Purchasers may need to use the API quality research data for pharmaceutical R&D, supplier evaluation, or related registration applications. The completeness of the documentation and the traceability of the data will affect the progress of subsequent projects.

However, a buyer's request for stability requirements does not necessarily mean an immediate purchase. Some enterprises are in the process of screening new raw material suppliers, some are still in the pharmaceutical R&D stage, and some buyers are only collecting documentation in accordance with their internal quality audit procedures. Suppliers still need to judge the project progress based on the procurement purpose and subsequent communication.

What Should Enterprises Do If They Only Have a COA and No Complete Stability Report?

This situation may occur among some intermediate trading enterprises, newly developed API products, or projects that have not yet reached the mature commercial supply stage.

First, it is necessary to confirm whether the enterprise has carried out relevant stability studies but has not yet organized the results into a report suitable for customer review.

Some manufacturing enterprises have established ongoing stability monitoring plans and possess inspection records at different time points, but usually only provide COAs externally. When overseas customers raise requests, the quality department can verify the existing research data, applicable batches, testing methods, and storage conditions to determine if a corresponding summary of the stability study can be formed.

If the enterprise has completed part of the stability study but has not yet covered the proposed re-test period, it should clearly state the extent to which the existing data can support, and which studies are still ongoing. One cannot directly assume that a product has stability evidence corresponding to a certain period just because it has been produced for many consecutive years.

If the product has indeed not undergone necessary stability studies, the requirements for supplementary studies need to be evaluated based on the product development and commercial supply plans. For API registration projects applicable to ICH Q1A(R2), stability data on at least three primary batches are usually required, and studies should be carried out in accordance with the corresponding storage conditions and time schedules; specific requirements still need to be confirmed in combination with the product type, registration pathway, and target market.

For APIs that have entered commercial production, ICH Q7 also requires the establishment of a documented ongoing stability monitoring program, and the use of study results to confirm appropriate storage conditions, re-test dates, or shelf life.

Suppliers cannot directly replace a stability study report with the COAs of the latest three batches. The three batches of COAs can help buyers observe the quality performance of different batches, but without study data at different storage time points, it is impossible to fully illustrate the product's changes during storage.

Do All Stability Research Information Need to Be Provided to Buyers?

In the process of overseas API procurement, stability study reports may contain batch information, testing methods, degradation trends, study conditions, and other quality technical data. Some content may also involve the production enterprise's commercial or technical confidential information.

Therefore, the scope of documentation to be provided should be determined based on the buyer's identity, project stage, and actual purpose.

If the buyer is only conducting a preliminary product assessment, a summary of the existing stability study can be provided first, including study conditions, inspection duration, key quality indicators, and existing research conclusions, to help them judge whether the product meets the project requirements.

If the buyer has entered the formal supplier audit, pharmaceutical development, or registration application stage, more detailed data, study reports, or document reference support may be required. When confidential information is involved, the appropriate submission method can be determined based on the cooperation relationship, non-disclosure agreement, and regulatory requirements of the target market.

For traders, it is also necessary to confirm whether the relevant stability documentation comes from the actual manufacturing enterprise, and whether the study batches, product specifications, and packaging conditions can correspond to the subsequent supplied products.

If a trader can only provide the COA of its partner factory but cannot confirm the basis for the re-test period, the stability study status, and the production source, overseas pharmaceutical manufacturers will raise further questions during the audit.

It should be noted that suppliers must not fill in unperformed test results on their own to meet customer requirements, nor use data from other manufacturers, different processes, or different packaging conditions directly as the stability proof of the current product. The research documentation must be authentic and traceable.

Stability Documentation Preparation Is Part of an Enterprise's Overseas Supply Capability

For API enterprises that plan to develop overseas pharmaceutical customers on a long-term basis, stability data should not be considered only after buyers make requests.

Especially for key promoted APIs, enterprises can check in advance the product specifications, COA, recommended storage conditions, re-test period, stability study status, and related quality documents, clarifying which materials can be provided directly, which need to be reviewed by the quality department, and which still require supplementary studies.

On professional pharmaceutical B2B platforms such as Drugdu.com, suppliers can indicate product quality standards, packaging specifications, recommended storage conditions, and the types of quality documents available on their product pages, allowing overseas buyers to understand the basic supply situation before making contact.

However, there is usually no need to upload the complete stability study report directly to the public. For customers involving registration, supplier audit, and commercial procurement, further document review and provision can be arranged after confirming specific requirements.

If an enterprise frequently receives inquiries from overseas buyers about stability data, re-test periods, or storage conditions, it is worthwhile to incorporate these issues into the documentation improvement work for key products. For mature APIs that have long been exported, the completeness of stability study documentation may directly affect the supplier audit progress of some overseas pharmaceutical manufacturers.

Overseas buyers' request for API stability data indicates that they are starting to pay attention to whether the product can maintain its quality under specified conditions after delivery, and whether the supplier can provide corresponding research evidence.

For suppliers, the COA is an important batch quality certificate, but it generally cannot replace stability studies. Especially for projects involving long-term storage, commercial pharmaceutical production, or drug registration, enterprises also need to provide reasonable data that can support storage conditions, re-test periods, and product stability.

If you currently only have a COA, you should first check the completeness of the existing research documentation, and then determine the content that needs to be supplemented based on the target customer and product usage. Clearly explaining the scope of support from existing data and documents is more convincing than simply promising "the product is stable with no quality issues".

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