LONDON Scientists in Scotland have come up with a way to make the drug cannabis soluble in a process that would facilitate its use for medicinal purposes as a painkiller and muscle relaxant.
Roger Pertwee of Aberdeen University said the breakthrough meant patients would not have to smoke or eat the drug methods which are damaging to health or unreliable.
Pertwee, a reader in neuropharmacology at the university, is recognized as Britain's leading researcher into the medical benefits of cannabis.
He is also secretary of the International Cannabis Research Society.
The team's research has attracted the interest of major drug companies in Britain and the United States, where some states allow cannabis to be used medically.
The British government banned the medically prescribed use of cannabis in 1971, but in recent years there has been a growing reluctance by prosecutors to take such users to court. The government is currently carrying out a trial involving 600 multiple sclerosis patients to assess the medical benefits of the drug.
Pertwee's team aimed to develop a cannabis compound which could be injected or used in aerosols or sprays.
It developed and patented the new compound in collaboration with two U.S. scientists, Boston-based Raj Razdan and Billy Martin.
Pertwee said he hoped the new breakthrough could eventually be combined with other compounds developed in the United States which relieve pain without producing a "high".
"At the moment the only ways to take cannabis are to smoke it, which is not really acceptable because of the carcinogenic risk, or to take the drug by mouth, where you get very variable and unreliable absorption," Pertwee said.
"The chances are it will produce the same effects as cannabis, which is a problem, but that's a different problem from the one we are dealing with," he added.
Pertwee said the painkilling effects of cannabis and the high were due to its action on two similar receptors in the nervous system, known respectively as CB1 and CB2, although scientists were developing cannabis compounds which did not affect the CB1 receptors.
"The challenge with cannabis-related compounds is to try to remove the unwanted central effects, which may be all right for people using the drug recreationally, but are no good if you're trying to relieve the pain of multiple sclerosis.
"Other compounds which selectively go to the CB2 receptors have already been developed and tested on animals. The fact that we have developed a water soluble compound suggests it would be possible eventually to create a compound which lets sufferers benefit from the pain relief without getting high," he said.
(DPA)