Bayer Plc has recalled Trasylol (aprotinin) injection 500,000kiu/50ml, 50ml vials, batch number CBKWS1, expiry date January 31, 2004. This is because of a failure of a valve involved in the cleaning process at the manufacturing plant. The valve was not involved in the manufacturing process and the batch remained within release specification. Recipients are requested to quarantine stock of this batch and return it to their supplier for credit or replacement. Further information can be obtained from medical information services at Bayer (tel 01635 563000).