Human chorionic gonadotropin (HCG), a polypeptide hormone produced by the human placenta, is composed of an alpha and a beta subunit. The alpha sub-unit is essentially identical to the alpha subunits of the human pituitary gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as to the alpha subunit of human thyroid-stimulating hormone (TSH). The beta subunits of these hormones differ in amino acid sequence.
PREGNYL® (chorionic gonadotropin for injection USP) is a highly purified pyrogen-free preparation obtained from the urine of pregnant females. It is standardized by a biological assay procedure. It is available for intramuscular injection in multiple dose vials containing 10,000 USP units of sterile dried powder with 5 mg monobasic sodium phosphate and 4.4 mg dibasic sodium phosphate. If required, pH is adjusted with sodium hydroxide and/or phosphoric acid. Each package also contains a 10-mL vial of solvent containing: water for injection with 0.56% sodium chloride and 0.9% BENZYL ALCOHOL, WHICH IS NOT FOR USE IN NEWBORNS. If required, pH is adjusted with sodium hydroxide and/or hydrochloric acid.