From: mspencer@ac.dal.ca
Newsgroups: sci.med
Subject: DMSO in transdermal meds?
Date: 28 Sep 92 01:17:37 -0300
Reply-To: mspencer@quasar.sba.dal.ca
Keywords: DMSO transdermal
Distribution: world
Organization: Dalhousie University, Halifax, Nova Scotia, Canada

Can anyone report authoritatively on whether or not the growing number 
of "transdermal" medications (patches, ointments and perhaps sprays) 
contain dimethyl sulfoxide (DMSO) as an ostensibly "inert carrier" 
ingredient?

These medications make no mention of DMSO in the "active ingredient" 
list but, according to my understanding, ostensibly "inert" 
ingredients need not be so listed.  I can't think of any other way 
that that drugs which don't normally penetrate the skin could be 
delivered by this route.  A non-exhaustive (indeed, hasty) review of 
what's on the market shows:

     Topically applied nitroglycerine for angina.
     Lidocaine paste as a substitute for subdermal lidocaine infusion.
     Estrogen patches for post-menapausal hormone therapy.
     Scopolamine patches for nausea and motion sickness.
     Various "puffer" sprays for respiratory problems that don't seem 
        to require deep inhalation to be effective.
     
---
Very brief background, if you never heard of DMSO:

In the late fifties it was accidentally discovered that, contrary to 
conventional medical wisdom/dogma,  DMSO penetrated the skin without 
disrupting it destructively.  Subsequent studies showed, among other 
things, that:

o    DMSO could carry dissolved substances across the skin barrier (and 
apparently also other barriers such as the blood/brain or the 
bladder wall).

o    DMSO has a pronounced anti-inflammatory effect.

o    DMSO is an effective analgesic for arthritic pain and pain 
associated with other forms of joint and connective tissue 
inflammation.

In the early 60's, there was a spate of hype in the popular press 
about the theraputic potential of DMSO before the customary sober 
results of acedemic scrutiny had appeared in the scientific 
literature.  From then to the early 80's there has been ongoing 
controversy on (U.S.) FDA approval of clinical trials or use, with 
charges of quackery emanating from the FDA and charges of 
obstructionism and persecution from clinicians and researchers.

DMSO came to be widely used as a topical analgesic and anti-
inflammatory in veterinary medicine, by athletes and by self-
medicating members of the public who suffered from afflictions 
such as arthritis, gout, back pain and  frozen shoulder.  

The list of disorders in which DMSO clearly can be, or might be, 
beneficially employed is quite long and includes cancer, arthritis and 
schleroderma.  Regretably, the appearance of such a list is not unlike 
the list of disorders allegedly cured by various crackpot Universal 
Panacaeas (tm) or by such screwball methodologies as iridology and has 
led to knee-jerk charges of quackery against any investigation of 
DMSO.  In fact, most of the looked-for benefits derive from anti-
inflammatory action (and inflammation underlies or follows on many 
disorders) or from the unique and (as far as I know) as yet 
unexplained solute-carrier effect.  For example, no one to my knowlege 
has suggested DMSO as a "cure for cancer", but rather that it might, 
with suitably contrived technology, solve the recognized problem of 
targeting and penetrating tumors by acting as a carrier for 
antineoplastic agents.

Is DMSO's unique transdermal carrier property being successfully 
exploited now as an "inert" ingredient because the FDA has refused to 
recognize it (with one or two limited exceptions) as an "active" 
medication?  

Have pharmaceutical companies conspired to suppress introduction of 
DMSO as an anti-inflammatory and analgesic?  The speculation here is 
that, as an (legally) "inert" substance, DMSO could be used in new 
preparations of already approved drugs while, were DMSO oficially 
regarded as an "active" substance, preparations containing it would 
have to undergo the very expensive FDA approval process.

Info about DMSO in transdermal medications or about the current 
political or clinical status of DMSO solicited.  

Reference: The latest reference I have is _DMSO: The True Story of a 
Remarkable Pain-killing Drug_, Barry Tarshis, Wm. Morrow & Co., 1981.

Followup to sci.med (or alt.conspiracy ;-) or email me.