Injection Pen: An Easy, Accurate, And Less Painful Drug Delivery Device! Injection pen is a popular method of drug delivery. This is now replacing the traditional syringe usage with lot of drugs available in the form of pre-filled disposable cartridges. These pens are widely used for injecting insulin and are expensive. Also, they eliminate the step of drawing insulin from the vial, which is a major advantage they offer. Keywords: Zechariah Lopez, Injection Pen, drug delivery