Circulation of COVID-19-Related Medicines on Japanese Websites during the COVID-19 Pandemic and Their Quality and Authenticity.

Substandard and falsified medical products for treating COVID-19 have spread worldwide. These medicines have entered Japan through personal importation of products purchased via the Internet. In this study, we investigated the circulation of 19 COVID-19-related medicines on the Internet in Japan and evaluated the pharmaceutical quality and authenticity of 2 medicines (dexamethasone tablets and ivermectin tablets) obtained online. We purchased 23 samples of 0.5-mg dexamethasone tablets and 13 samples of 3-mg ivermectin tablets from the Internet in December 2020 and July 2022. We investigated the quality and authenticity of the obtained samples through visual observation and tested their authenticity. We conducted pharmacopoeia compliance testing (quantitative assay, content uniformity tests, and dissolution tests) using the high-performance liquid chromatography-photodiode array detector method. No prescription was ever required at the time of purchase. Visual observation revealed that most samples lacked a package insert and some samples had packaging deficiencies. In terms of authenticity, eight ivermectin samples were genuine; the authenticity of the other samples remained uncertain. Four dexamethasone samples and three ivermectin samples failed quality testing based on pharmacopeia validation standards. Our findings illustrate that dexamethasone and ivermectin tablets of poor quality are available online. It is important to increase consumer awareness and provide information about these medicines to prevent the purchase of substandard medicines via the Internet.