Isosource High-Nitrogen Complete, Unflavored, 250 mL (8.45 oz.) Reclosable Tetra Prisma Carton. 300 Calories per 250 mL. A high-protein, tube-feeding formula providing 1.2 calories per mL and 54 grams of protein per 1000 mL. Lactose-free, Gluten-free.