What is Protropin?
Protropin® (somatrem for injection) is a polypeptide hormone produced by recombinant DNA technology. Protropin has One Hundred and Ninety Two amino acid residues and a molecular weight of about 22,000 daltons. Protropin contains the same sequence of One Hundred and Ninety One amino acids constituting pituitary-derived HGH plus an extra amino acid, methionine, on the N-terminus of the molecule. Protropin is synthesized in a special laboratory strain of E. coli bacteria which has been modified by the addition of the gene for human growth hormone production. Unlike many brands of HGH therapy, Protropin is not biologically identical to natural human growth hormone, but it is functionally identical, meaning that it promotes the same physiological changes within the human body. In fact, somatropin (bio-identical HGH) and somatrem are nearly exactly the same, with only one molecular difference-an extra methionine molecule attached to the end of the compound. Protropin is a highly purified preparation.
The biological effect is determined by measuring the increase in body weight induced in specially selected rats. Protropin is a sterile, white, lyophilized powder intended for intramuscular or subcutaneous administration after reconstitution with Bacteriostatic Water for Injection, USP (benzyl alcohol preserved). Lyophilized simply means that medication is freeze-dried in order to extend its potency and storage longevity. Reconstitution is a simple process in which purified water is added to the freeze-dried Protropin, restoring it to an active state for injection. In the case of Protropin, the water is combined with preservatives in order to extend the life of the reconstituted treatment. Each 5 mg Protropin vial contains 5 mg (approximately 15 IU) somatrem, lyophilized with 40 mg mannitol, and 1.7 mg sodium phosphates (0.1 mg sodium phosphate monobasic and 1.6 mg sodium phosphate dibasic). Each 10 mg Protropin vial contains 10 mg (approximately 30 IU) somatrem, lyophilized with 80 mg mannitol, and 3.4 mg sodium phosphates (0.2 mg sodium phosphate monobasic and 3.2 mg sodium phosphate dibasic). Phosphoric acid may be used for pH adjustment. Bacteriostatic Water for Injection, USP is a sterile water with 0.9% benzyl alcohol per ml as a preservative against microbes packaged in a vial. The diluent pH is 4.5-7.0.
What is Protropin used for?
Protropin® somatrem for injection is indicated only for the long term treatment of children who have growth failure due to a lack of adequate hormone secretion. Other etiologies of short stature should be excluded. Protropin was the first recombinant-DNA medication ever created.