Letter from William Srigley, Director of Regulatory Affairs and Quality Control at Hyland Therapeutics, to Elaine Esber, Director at the Office of Biologics Research and Review at the Center of Drugs and Biologics. Writes advising that Hyland Therapeutics Division of Travenol Laboratories wishes to amend its product license application for Antihemophilic Factor (Human) to include an optional manufacturing procedure which will be called Antihemophilic Factor (Human), Method C, Heat-Treated