The Bradford-based company, which is trying to commercialise its technology for the treatment of dermatological and consumer healthcare conditions, said the deal with Sinclair Pharma will involve developing new combination formulations.
Sinclair will pay Syntopix a development contract fee to develop combination formulations using Sinclair's delmopinol and some potentially synergistic anti-microbial compounds.
Syntopix said it will receive royalties if any of the formulations for oral health or other medical applications are commercialised.
The deal follows an initial agreement in April
Dr Stephen Jones, chief executive of Syntopix, said: "I am delighted that the collaboration Syntopix and Sinclair embarked on in April has been a success.
"As a leading company developing treatments for diseases/problems of the skin and mouth, Sinclair's expertise is closely aligned with our own and together we are in a strong position to develop unique and effective products."