<span class="citations"><p>Thomas F. McNamara, Nungavaram S. Ramamurthy, Lorne M. Golub, "Non-antibacterial tetracycline compositions possessing anti-collagenolytic properties and methods of preparing and using same." U.S. Patent US4704383, issued May, 1963.</p>
</span><a href="https://www.google.com/?tbm=pts#q=4704383&amp;tbm=pts" rel="noopener" target="_blank">US4704383</a>