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Atthachai Homhuan

Director, Regulatory Affairs


Dr. Atthachai Homhuan is the director of the regulatory affairs department at Tilleke & Gibbins. Atthachai assists chemical, life sciences, pharmaceutical, and biotechnology companies to draft and review their patent claims and specifications. He advises patent agents on amending claims and providing responses to office actions. Atthachai frequently drafts counterstatements against opposing parties in trademark and patent applications. His practice also includes advising on pre-litigation and litigation matters involving the life sciences, medical devices, and pharmaceuticals. He has presented before the IP&IT Court as a witness in chemistry and life sciences patent litigation.

In addition to patent work, Atthachai prepares healthcare product dossiers for registration and he helps international companies develop market entry strategies for countries in Southeast Asia. His broad experience allows him to evaluate the feasibility of product registrations, conduct plant audits, and coordinate pre-clinical and clinical trials in accordance with international guidelines and standards. Atthachai also reviews healthcare product labeling for food, cosmetics, medical devices, and drug products in Thailand and other Southeast Asian countries.

Prior to joining the firm, Atthachai was a postdoctoral researcher in Japan and Taiwan, focusing on stem cell therapies and vaccine development. He applied his technical expertise to the industry when he became a project manager for a Thai vaccine manufacturing company, where he led the firm’s R&D efforts. His industry background also includes serving as a formulation manager at the subsidiary of a well-known American pharmaceutical innovator, where he was a group leader in charge of the company’s R&D and production functions.

Atthachai holds a PhD in Pharmaceutical Technology from Thailand’s Mahidol University, and he frequently lectures on pharmaceutical and chemical patents at universities across Thailand. He has completed the South East Asian Drafting Training Couse, enabling him to prepare patent applications and claims.


  • Revised guidelines for Thai patent officers examining chemical and pharmaceutical patents.
  • Implemented a quality system and GMP-related topics for the manufacturing of vaccines. This involved working closely with the Department of Medical Sciences of the Thai FDA in regard to biohazard manufacturing, ex-plan audit, in order to obtain approval.
  • Participated in conducting clinical trials and bioequivalence studies for new drugs and conventional products, and ensured the trials/studies and protocols were in accordance with the Good Regulatory Practices and Good Clinical Practices.
  • Co-invented several pharmaceutical products regarding liposomal vaccines and stem cell therapy, each of which is patented in Japan.
  • Assisted life sciences and chemical companies to draft a variety of complex patents involving the manufacturing process of creating polymers from waste gas and patents related to biological vaccines, among others.
  • Audited leading pharmaceutical companies to ensure that their product registration dossiers and advertising campaigns comply with Thai legislation.
  • Registered new biological product dossiers at the Thai FDA and received approval within 1.5 years—a short period of time to obtain approval for a new drug in Thailand.
  • Registered medical devices, food products, and cosmetics with the Thai FDA for domestic and international companies.
  • Worked with the firm’s litigation team and won a disputed patent litigation case for a chemical glass company, in which the opposing party claimed damages exceeding THB 50 million.
ABOUT Atthachai


Life Sciences






    PhD, Mahidol University

    BSc, Chulalongkorn University


Awards & Rankings

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