Octreotide acetate
[CAS# 83150-76-9]

Identification

• Classification: Biochemical >> Peptide
• Name: Octreotide acetate
• Synonyms: [R-(R*,R*)]-D-Phenylalanyl-L-cysteinyl-L-phenylalanyl-D-tryptophyl-L-lysyl-L-threonyl-N-[2-hydroxy-1-(hydroxy-methyl)propyl]-cysteinamide cyclic(2->7)-disulfide
• Protein Sequence: FCFWKTCT
• Molecular Formula: C₄₉H₆₆N₁₀O₁₀S₂^.2(C₂H₄O₂)
• Molecular Weight: 1139.35
• CAS Registry Number: 83150-76-9
• SMILES: C[C@H]([C@H]1C(=O)N[C@@H](CSSC[C@@H](C(=O)N[C@H](C(=O)N[C@@H](C(=O)N[C@H](C(=O)N1)CCCCN)CC2=CNC3=CC=CC=C32)CC4=CC=CC=C4)NC(=O)[C@@H](CC5=CC=CC=C5)N)C(=O)N[C@H](CO)[C@@H](C)O)O

Properties

• Density: 1.4±0.1 g/cm³ Calc.^*
• Boiling point: 1447.2±65.0 ºC 760 mmHg (Calc.)^*
• Flash point: 829.1±34.3 ºC (Calc.)^*
• Index of refraction: 1.673 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H317-H319
• Precautionary Statements: P280-P305+P351+P338

Discovory and Applicatios

Octreotide acetate is a synthetic cyclic octapeptide and a long-acting analogue of the endogenous hormone somatostatin. It is designed to mimic the inhibitory effects of natural somatostatin while exhibiting a substantially prolonged biological half-life. Octreotide acetate has been widely used in clinical medicine for the regulation of excessive hormone secretion and for the management of several endocrine and gastrointestinal disorders.

Octreotide acetate is composed of eight amino acids arranged in a cyclic structure stabilized by a disulfide bond. This structural modification enhances metabolic stability and receptor selectivity compared with native somatostatin. The acetate salt form improves solubility and formulation stability for parenteral administration. Due to its peptide nature, octreotide acetate is not orally bioavailable and is administered via subcutaneous or intramuscular injection.

Octreotide acetate exerts its pharmacological effects by binding to somatostatin receptors, with high affinity primarily for receptor subtypes SSTR2 and SSTR5. Activation of these receptors leads to inhibition of adenylate cyclase activity, reduced intracellular cyclic AMP levels, and suppression of hormone secretion. Through these pathways, octreotide acetate inhibits the release of growth hormone, insulin, glucagon, serotonin, gastrin, and other biologically active peptides.

The compound demonstrates potent antisecretory activity, reducing excessive hormonal output in pathological states. In addition to endocrine effects, octreotide acetate decreases splanchnic blood flow and inhibits gastrointestinal motility and exocrine secretions. These combined actions contribute to its therapeutic utility in managing hormone-related disorders and gastrointestinal bleeding conditions.

Octreotide acetate is widely used in the treatment of acromegaly to suppress excessive growth hormone secretion when surgery or radiotherapy is insufficient or contraindicated. It is also employed in the management of neuroendocrine tumors to control hormone-mediated symptoms such as flushing and diarrhea. In gastroenterology, octreotide acetate is used to control acute variceal bleeding and to reduce pancreatic secretions following pancreatic surgery or fistula formation.

After subcutaneous administration, octreotide acetate is rapidly absorbed, with peak plasma concentrations occurring within a few hours. The compound exhibits a significantly longer half-life than native somatostatin, allowing for sustained pharmacological activity. It is primarily eliminated via hepatic metabolism and renal excretion of metabolites.

Octreotide acetate is generally well tolerated when administered at therapeutic doses. Common adverse effects include gastrointestinal disturbances such as abdominal discomfort, nausea, and altered bowel habits. Long-term use may affect gallbladder motility, leading to gallstone formation in some patients. Careful monitoring is recommended during extended treatment courses.

Beyond its established clinical applications, octreotide acetate continues to be investigated for potential roles in oncology, metabolic disorders, and inflammatory conditions. Its receptor selectivity and inhibitory properties make it a valuable tool in both therapeutic and research settings for studying hormone-regulated physiological processes.

References

Battershill PE, Clissold SP (1989) Octreotide: a review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in conditions associated with excessive peptide secretion. Drugs 38(5) 658–702 DOI: 10.2165/00003495-198938050-00002

Rinke A, Müller HH, Schade-Brittinger C, et al. (2009) Placebo-controlled, double-blind, prospective, randomized study on the effect of octreotide LAR in the control of tumor growth in patients with metastatic neuroendocrine midgut tumors: a report from the PROMID Study Group. Journal of Clinical Oncology 27(28) 4656–4663 DOI: 10.1159/000443612

Andre A, Squittieri N, Patil SB (2021) Evaluation of the octreotide acetate pen injector and its instructions for use in a formative human factors study. Advances in Therapy 38(6) 3129–3142 DOI: 10.1007/s12325-021-01739-1