 Purisys will supply ultra-high purity cannabinoids for use in GB Sciences cannabinoid-containing, optimized therapeutic mixtures OTM. LAS VEGAS, NV ACCESSWIRE April 20, 2021 GB Sciences, Inc. OTCQB:GBLX and Purisys, LLC, the global industry leader in ultra-high purity, pharmaceutical grade cannabinoid supply, today announced that GB Sciences has selected Purisys as their preferred vendor for the active pharmaceutical ingredients APIs used in formulating GB Sciences proprietary, cannabinoid-containing, optimized therapeutic mixtures OTM. 