Presentation: Each pre filled disposal pen for subcutaneous injection contains 0.3mg of IGF 1 with Pre – mixed powder and solvent solution.You never have to change cartridges. When the pen is empty, you just start a new pen. Non re fillable pen. Pen is packed in a printed Keifei logo PVC bag in a print box with QR authentication code. Storage: The IGF 1 Pen is mixed only once, when you start a new pen. A single pen can be used up to 28 days after mixing. At all time it must be Stored at 2 c – 8c.