Comments on: A bitter pill to swallow

By: Anonymous

Anonymous — Sat, 21 May 2005 08:01:37 +0000

The physical & chemical properties of a drug product determine whether or not you make a tablet or a capsule (or an injectable).

Aspirin tablets can be made with 100% pure drug! However, acetominophen, which has essentially the same pharmaceutical effects cannot — it simply cannot be compressed without the addition of ‘binders’. When you add binders, then you have to add disintegrants to make the tablet dissolve!

By: Lednicer

Lednicer — Fri, 20 May 2005 11:31:03 +0000

Cogniosceti actually prefer the term controlled release to point to their boast that they can taylor the rate at which drug is presented to the bloodstream. This is ususally accomplished by first preparing the drug in microencapsulated form. The coating on those tiny particles dictates how quickly they release drug (see my “A Capsule History” in Invention and Technology, p.50, Volume 18, 2003). These are then packed into standard gelatin capsules. It is possible to arrange for a very extended concentrations of drug by including microcapsules with staggered release rates,

By:

Thu, 19 May 2005 03:03:30 +0000

…thanks for adding that Dan. One additional point I thought of after reading your reply: there are “slow-release” capsules out there too, which presumably have a coating that takes longer to dissolve so that the contents enter the stomach over a more protracted period of time rather than almost at once as is the case with a tablet or a standard capsule.

By: Lednicer

Lednicer — Wed, 18 May 2005 16:12:06 +0000

To take you second question first, there should be no apprecialble difference in release between the two dosage forms. Tablets completely disintegrate in the stomach as should capsule shells. Both thus let loose drug substance in the stomach. One of the rate controlling steps in availabity is the dissolution of active drug substance.

Capsules vs tablets is basically a trade-off. It is usually more difficult to develop tablets because they not only have to stay intact under a wide range of conditions (eg shaking in a truck) but then have to disintegrate on demand. Capsules are easier to design because at best you may need to add an inert diluent. It is cheaper to manufacture tablets on the other hand because presses are so much faster than filling machines and you avoid the extra cost of capsule shells.

The quick and easy answer then is: it depends..

By:

Wed, 18 May 2005 12:26:37 +0000

Perhaps Dr Lednicer would care to comment?

By: Eponymous Zero

Eponymous Zero — Wed, 18 May 2005 12:11:29 +0000

I wondering why some drugs are manufactured as tablets, and some as capsules?

Is it just that capsules prevent the active ingredient being released too early, or is it more complicated than that?

Thanks for the fascinating article…