WHO Expert Committee on Specifications for Pharmaceutical Preparations - WHO Technical Report Series, No. 885 - Thirty-fifth Report
(1999; 168 pages) [Spanish] View the PDF document
Table of Contents
View the documentWHO Expert Committee on Specifications for Pharmaceutical Preparations
View the document1. Introduction
Open this folder and view contents2. The international pharmacopoeia and related issues
Open this folder and view contents3. International Chemical Reference Substances and Infrared Reference Spectra
Open this folder and view contents4. Quality control - national laboratories
Open this folder and view contents5. Good manufacturing practices
Open this folder and view contents6. Quality systems and inspection
Open this folder and view contents7. Other quality assurance topics
Open this folder and view contents8. Nomenclature and terminology
Open this folder and view contents9. Legal aspects of pharmaceuticals
Open this folder and view contents10. Regulatory issues
Open this folder and view contents11. Training activities
View the document12. Pharmaceuticals contaminated with diethylene glycol
View the documentAcknowledgements
View the documentReferences
View the documentAnnex 1. List of available International Chemical Reference Substances1
View the documentAnnex 2. List of available International Infrared Reference Spectra1
Open this folder and view contentsAnnex 3. General guidelines for the establishment, maintenance and distribution of chemical reference substances
Open this folder and view contentsAnnex 4. Good manufacturing practices: authorized person - role, functions and training
Close this folderAnnex 5. Good manufacturing practices: supplementary guidelines for the manufacture of pharmaceutical excipients
View the document1. General considerations
View the document2. Glossary
View the document3. Self-inspection and quality audits
Open this folder and view contents4. Equipment
Open this folder and view contents5. Materials
Open this folder and view contents6. Documentation
Close this folder7. Good practices in production and quality control
View the document7.1 Change control and process validation
Close this folder7.2 Good practices in production
View the document7.2.1 Prevention of cross-contamination
View the document7.2.2 In-process blending/mixing
View the document7.2.3 Control of microbial contamination
View the document7.2.4 Water systems/water quality
View the document7.2.5 Packaging operations
View the document7.2.6 Delivery
Open this folder and view contents7.3 Good practices in quality control
Open this folder and view contentsAnnex 6. Guidelines for inspection of drug distribution channels
View the documentAnnex 7. Good pharmacy practice in community and hospital pharmacy settings
Open this folder and view contentsAnnex 8. National drug regulatory legislation: guiding principles for small drug regulatory authorities
Open this folder and view contentsAnnex 9. Provisional guidelines for developing training programmes: inspection and examination of counterfeit pharmaceuticals
View the documentWorld Health Organization Technical Report Series
View the documentSelected WHO Publications of Related Interest
View the documentBack Cover
7.2.1 Prevention of cross-contamination

Potential for cross-contamination should be considered in the design of the manufacturing process and facility. The degree to which cross-contamination should be minimized depends on the safety and intended use of the excipient.

The precautions taken to minimize cross-contamination should be appropriate to the conditions of the manufacturing facility and will take account of the range of materials manufactured. When the excipient product is initially recovered, it should be in a clean environment and not exposed to airborne contaminants, such as dust from other excipient or industrial chemicals. Typically, the damp product will be unloaded into clean, covered containers and transported for drying and other manipulations. These subsequent operations should be performed in separate areas or under controlled conditions because once dry, the excipient is more likely to contaminate its environment, including any surrounding products. The primary consideration is that the building and facilities should not contribute to an actual or potential contamination of the excipient.

The air handling systems at the site of manufacture should be designed to prevent cross-contamination. In dedicated areas processing the same excipient, it is permissible to recycle a portion of the exhaust air back into the same area. The adequacy of such a system of operation for multi-use areas, especially if several products are processed simultaneously, should be carefully analysed. In multi-use areas where several products are completely confined in closed vessels and piping systems, filtration of the supply air (combined fresh make-up air and recycled air) is acceptable if the conditions are consistent with other existing regulations (e.g. environmental, safety).

In those areas where the excipient is in a damp or moistened form, such as filter or centrifuge cake, and may be exposed to room air, filter efficiencies in the supply air system as low as 85% may be adequate. In those areas where one or more of the products is being processed in a dry form, such filtration may not be enough to prevent cross-contamination. In all cases, manufacturers should be able to demonstrate the adequacy of their air handling systems.

Excipient manufacturers should have a documented programme identifying all insecticides, pesticides, rodenticides and herbicides used at the site of manufacture. Adequate measures should be taken to prevent these agents contaminating the excipients.

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