On 26 April 2009, the US Food and Drug Administration (FDA) released for comment, Draft Guidance for Industry and FDA Staff: Technical Considerations for Pen, Jet, and Related Injectors Intended for Use with Drugs and Biological Products. The document-prepared by the Office of Combination Products in conjunction with the Center for Devices and Radiological Health, the Center for Drug Evaluation and Research and the Center for Biologics Evaluation and Research-reflects FDA's current thinking on the development and registration of a variety of prefilled and unfilled injection devices including jet injectors, pen injectors, needle-free injectors, mechanically operated injectors and injectors with computerized or electronic elements. It also covers piston syringes.