PurAmino Infant Powder 14.1 oz., Amino Acid based formula. 1,960 Calories Per Can. PurAmino is a 20 Cal/fl oz, iron-fortified, hypoallergenic, amino acid-based infant formula for the dietary management of infants with severe cows milk protein allergy, not effectively managed by an extensively hydrolyzed formula. PurAmino is also indicated for the dietary management of infants with multiple food protein allergies. It may also be suitable for conditions requiring an elemental diet such as protein maldigestion, malabsorption, short bowel syndrome and eosinophilic esophagitis.