Due to the production of a novel, flexible intermediate in our alkaloid biosynthetic pathway, River Stone Biotech can produce a number of APIs at reduced cost, via a highly efficient process that delivers an improved environmental footprint. Currently, priority focus is on products indicated for the treatment of substance use disorders: Buprenorphine, Naloxone and Naltrexone.

We are actively researching and harnessing our technology to discover areas that would benefit from expanding our portfolio beyond the current products.

  • DMFs and CEP documentation will be available with manufacture under cGMP at a European based FDA and EMA approved manufacturing facility, thereby meeting the regulatory requirements for global supply.
  • River Stone Biotech’s unique synthetic biology technology offers scope to manufacture a wide range of alkaloid APIs. By the incorporation of a patented bioconversion process River Stone Biotech’s API manufacturing process eliminates the presence of many of the pharmacopeial listed impurities.
  • Customized particle size specifications can also be realized.

Approved by the FDA, EMA and other global regulatory authorities, Buprenorphine is indicated in the treatment of opioid use disorder and pain. Existing medications encompass both monotherapy and combination therapy (buprenorphine/naloxone) dose forms.

  • River Stone Biotech produces Buprenorphine via a novel mixed biological and chemical synthesis in accord with the USP and EP Pharmacopeia.
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Naloxone is an opioid antagonist and a life-saving medication that rapidly reverses opioid overdose – the leading cause of accidental deaths in the US. It may also be combined with Buprenorphine as a combination therapy for treating OUD.

  • River Stone Biotech produces Naloxone Hydrochloride dihydrate in accord with the USP and EP Pharmacopoeia.


Naltrexone is a medication used in the treatment of alcohol use disorder and opioid use disorder. It is also used in combination with Bupropion as a therapeutic for obesity.

  • River Stone Biotech produces Naltrexone hydrochloride in accord with the USP and EP Pharmacopoeia.

Other Nal Products

River Stone Biotech is also exploring utilizing its platform to produce other Nal-type molecules and compounds that show therapeutic potential, including: Nalmefene, Nalbuphine, Methylnaltrexone and Naloxegol.

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River Stone Biotech’s novel, hybrid approach to API production offers scope to manufacture a range of Alkaloids. These naturally occurring bases are primarily found in plants and have been the subject of several major medical discoveries. Whilst the opioid receptors are the primary target for River Stone Biotech’s initial API offerings, it is widely understood that other Alkaloids have substantial effect on a variety of other receptors, including those involved with several neurodegenerative disease states.

Medical need, market size and partnership opportunity will converge as River Stone Biotech prioritizes subsequent production processes to enable its growing portfolio of more environmentally friendly and lower cost API’s. Specifically, we are identifying cumbersome steps in synthesis schemes for a number of high volume, high price APIs that could be performed by bioconversion or in vitro enzyme catalysis in less complex and hence less expensive ways.

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