Isolation of ocular hypotensive agents from Cannabis sativa

Recent work in our laboratories has shown that a hydrophilic fraction from Cannabis sativa (marihuana) has extremely potent intraocular pressure (IOP)-lowering activity as measured in albino rabbits when delivered by intravenous injection. A crude extract reduced IOP by 50-60 per cent (to the episcleral venous pressure) at dosage levels of about 500 micrograms/animal. Fractionation of this material by solvent extraction, high-performance liquid chromatography, and gel filtration chromatography has produced samples with high activity at 50 micrograms/animal. The active material has been shown to be noncannabinoid and of high molecular weight.