Methylnaltrexone Bromide

Opioids are the core medications for the treatment of cancer pain and chronic moderate to severe pain. However, the incidence of opioid-induced constipation (OIC) caused by long-term use is as high as 40% to 80%, and the response rate of conventional laxatives is less than 50%, which has become one of the main bottlenecks in clinical pain management. Methylnaltrexone bromide is a peripheral μ-opioid receptor antagonist. Its quaternary ammonium salt structure is difficult to penetrate the blood-brain barrier, and it can specifically block the effect of opioid receptors in the gastrointestinal tract without affecting the central analgesic effect. It is currently one of the first-choice drugs for targeted therapy of OIC, and its main applicable populations include advanced cancer patients receiving palliative care and patients with chronic non-cancer pain who use opioids for a long time.

The global market size of methylnaltrexone bromide was approximately USD 420 million in 2023, and the compound annual growth rate from 2024 to 2030 is expected to be 6.8%. The growth momentum mainly comes from the increase in the penetration rate of palliative care for cancer pain and the release of long-term medication demand of patients with chronic pain. China's OIC targeted drug market is still in the introduction stage. At present, only 3 enterprises have obtained marketing approval for generic methylnaltrexone bromide, and there is no relevant implemented centralized procurement policy. The original research product still accounts for nearly 60% of the in-hospital market share, and the supply of APIs has long been dominated by the original research manufacturer and European and American suppliers, so the domestic generic substitution space is considerable.

The original research enterprise of methylnaltrexone bromide is Bausch Health (formerly Valeant Pharmaceuticals), and the original research trade name is Relistor. The core compound patents expire in 2028 and 2029 in the United States and the European Union respectively. The main dosage forms approved for the original research product include subcutaneous injection (8mg/0.4ml, 12mg/0.6ml) and oral tablet (150mg). Among them, the subcutaneous injection has been included in the FDA Reference Listed Drug Catalog, and is also included in the *Catalog of Reference Preparations for Chemical Drugs (29th Batch)* of China. Up to now, the API registration platform of China CDE has recorded a total of 4 registration numbers for methylnaltrexone bromide APIs, 2 of which are in Status A and can be associated with the review and approval of domestic preparations. In China, methylnaltrexone bromide for injection from 2 enterprises and methylnaltrexone bromide tablets from 1 enterprise have been approved for marketing. (Data as of April 2025, please refer to the official CDE website for the latest information)

In response to the impurity research needs in the process of R&D and quality control of generic methylnaltrexone bromide, CATO can provide a full set of impurity reference standards for this API. Most of the products are in stock. For in-stock products, orders placed before 16:00 will be shipped on the same day. All products comply with the compliance requirements of multiple regulatory systems such as the Chinese Pharmacopoeia and FDA, and can meet the full-process technical needs such as impurity qualitative analysis, quantitative analysis and stability research.