Blending batches of intermediates or active substances
Article 37
1. Out-of-specification batches shall not be blended with other batches for the purpose of meeting specifications. 2. Each batch incorporated into the blend shall: (a) have been manufactured using an established process; and (b) have been individually tested and found to meet appropriate specifications prior to blending. 3. Acceptable blending operations include: (a) blending of small batches to increase batch size; (b) blending of tailings (e.g. relatively small quantities of isolated material) from batches of the same intermediate or active substance to form a single batch. 4. Blending processes shall be adequately controlled and documented and the blended batch shall be tested for conformity to established specifications, where appropriate. 5. The batch record of the blending process shall allow traceability back to the individual batches that compose the blend. 6. Where physical attributes of the active substance are critical (e.g. active substances intended for use in solid oral dosage forms or suspensions), blending operations shall be validated to show homogeneity of the combined batch. Validation shall include testing of critical attributes (e.g. particle size distribution, bulk density, and tap density) that may be affected by the blending process. 7. Where the blending may adversely affect stability, stability testing of the final blended batches shall be performed. 8. The expiry or retest date of the blended batch shall be based on the manufacturing date of the oldest tailings or batch in the blend.