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02/27/2008
Inactive Stuff
First, a correction – mea culpa. Apparently, time flies even when
you’re not having fun. In last week’s column, I commented on
all the media articles last year on Einstein in commemoration of
the hundredth anniversary of his “miracle year”. Einstein’s
miracle year was actually in 1905, making the actual hundredth
anniversary in 2005. It seems like only yesterday. Obviously,
my care giving duties have warped my sense of time.
One of the chores of care giving after her two spinal surgeries
and her recent fall has been managing the proper administration
of my wife’s medications. Over the past seven months or so
these medications have included Nexium, Sucralfate,
Amitriptyline, Norvasc, Benicar, Vicodin, Dilaudid, Toprol,
Oxycontin, Lyrica, Tylenol 3, Mylanta, Tramadol, Advil, Aleve,
Voltaren, and various over the counter laxatives, stool softeners,
and other prescription drugs I can’t recall at the moment. It’s
somewhat frightening that Heath Ledger’s drug list included
essentially all of the drugs my wife has been or had been taking
within the recent past!
Just trying to time the delivery of the various meds is a
challenge. For example, Nexium suppresses gastric acid
production while Mylanta acts as an antacid and Sucralfate forms
a sort of patch over an ulcer, according to our pharmacist. One
should be taken on an empty stomach, 2 hours after or 1 hour
before a meal, another should be taken a half hour before a meal
and one should not be taken within a half to an hour after taking
another. Mix in the pain meds and it becomes a real balancing
act.
The Nexium samples we received came with a very extensive
sheet in very fine print describing the contents, uses, precautions,
etc., etc. concerning the drug, advertised widely as “The Purple
Pill”, a trademark. I was intrigued by the number and identities
of the inactive ingredients, having just read a short article by
Steve Ritter titled “Excipients” in the January 25 issue of
Chemical and Engineering News (C&EN). The main ingredient,
known as the “active pharmaceutical ingredient” (API) in the
trade, is housed or carried in a mix of inactive ingredients, the
excipients. Excipients are roughly a $4 billion dollar a year
industry, according to Ritter, quoting a report by BCC Research.
Excipients hold the dose of API together, make sure it’s stable
enough to last on the shelf, make sure the API gets delivered in
the body at the appropriate time and place and mask any
unpleasant taste or odor, etc. Excipients also are used to bulk up
a pill and may be mixed with the API to ensure that during the
manufacture of the pill each pill contains essentially the same
dosage. Excipients known as glidants or granulating agents help
the powder mix flow freely in the manufacturing machinery
while lubricants or antiadherent excipients keep pressed tablets
from sticking to the machinery.
Sometimes you read or hear of cases where a generic form of a
drug doesn’t behave exactly as does the original drug. Such
cases may involve the use of different excipients. Coatings
contain excipients that, for example, may allow the pill to sail
through the acidy stomach but dissolve in the less acid intestine.
Disintegrants are excipients that expand and dissolve when wet;
this allows the tablet to fall apart rather than travel all the way
through the body without delivering the API.
Many or most of the excipients used in drugs are byproducts of
the food processing industry, according to Ritter. These inactive
ingredients have a long track record for safety in foods, beers etc.
and don’t have to go through hurdles clearing the FDA. I was
interested to read that drug companies tend to stick with the same
excipients throughout the life of a patent, one reason being that
any change in the formulation has to go back to the FDA for
approval.
I got out a magnifying glass to read the inactive ingredients in
Nexium and was intrigued with the excipients in the shell (our
Nexium comes in a capsule). There are 4 dyes (blue, 2 reds and
yellow) that I imagine combine to give the trademark purple
color. There are also ethyl, isopropyl and n-butyl alcohols,
titanium dioxide, propylene glycol, polyvinyl pyrrolidone,
sodium hydroxide and shellac! That’s just in the shell of the
capsule. Inside, in addition to the API, is an equally impressive
bunch of excipients. There’s a lot of chemistry going on in
formulating and manufacturing these drugs.
Needless to say, I’m looking forward to the day when both my
wife and I get back to the state where all we have to worry about
are our blood pressure, cholesterol, and/or the usual pile of
vitamins and other assorted relatively benign pills.
Allen F. Bortrum
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