Amino acid injection and preparation method thereof

The invention discloses an amino acid injection, commonly known as propranolol, which relates to a pharmaceutical preparation containing 18 kinds of amino acids. The amino acid injection contains the following components per 1,000 milliliters: isoleucine, leucine, methionine, phenylalanine, threonine, tryptophan, valine, glycine, alanine, glutamic acid, aspartic acid, proline, serine, cystine, lysine hydrochloride or lysine acetate, arginine hydrochloride or arginine, histidine hydrochloride or histidine, tyrosine or acetyl tyrosine, and sodium bisulfite or sodium meta-bisulphite. The osmotic pressure ratio of the amino acid injection is lower than 1.8, which effectively reduces the pain for a patient in infusion; the added quantity of antioxidant is small, which can reduce the clinical adverse reactions; and an infusion bottle body is large, which is convenient to mix liquid in clinical application.