Giz Explains: Why Some Pills Are Little White Discs And Others Are Big Red Torpedoes

Pills, they're the answer to every one of life's little problems, or so the pharmaceutical companies would like us to think. They come in all sorts of shapes, sizes and colours, but have you ever thought about why? Why are some boring white and round, while others are bright pink and look like a torpedo?

To get to the bottom of pills, you have to first look at the delivery mechanism -- where is the pill meant to end up, and where is it designed to be dissolved? The simplest or most common example is the humble paracetamol tablet; I can't imagine how many of those tiny white pain-relievers I've swallowed over my lifetime. Have you ever kept it in your mouth a little too long? It tastes foul and starts to dissolve immediately. That's because the tablet is destined for your stomach, the first stop on the magical mystery tour that is your gut.

Tablets, Capsules or Halfway In Between?

Pills that don't need to survive past the stomach, mainly because their contents - the drugs you so desperately need - are acid stable, therefore don't need much, if any, of a protective coating. That's why tablets often taste horrible, because there's nothing between your tongue and the drugs and packing agents that make up the pill. Other pills, such as lower digestive tract-targeted capsules like Immodium, or the majority of anti-biotics that need protection from the harsh acidic environment of the stomach, need torpedo-like casings to keep them safe. They're often coated in hard starch-based two-piece shells, which form that essential protective barrier and control the drug's release. That's why some pills are just chalky, solid tablets, and others are capsules forming hollow mini bombs, full of stuff you're never meant to see.

Of course, not all tablets are the same size and shape either. Your common white and chalky tablet has somewhat given way to a new raft of "caplets." These new-fangled pills, which are essentially your bog standard round tablet compressed into a different shape, are meant to be easier to swallow. They're slightly more expensive to produce, or at least they're slightly more costly to buy, but they do exactly the same thing - hit that stomach acid and dissolve, releasing the goods to be absorbed into your bloodstream.

Blue and Yellow Purple Pills

Pills, in all their various shapes and sizes, also come in a myriad of different colours. Since the 1960s, when colour pigment technology hit the pharmaceutical companies already churning out millions of pills, we've had almost every colour under the Sun available; 80,000 different colours to be exact. But why are different pills different colours?

The obvious answer is because they look pretty, and while that's surely part of it -- you're more likely to remember an attractive-looking pill than some crappy white one -- the real reason was, at least in the beginning, just because they could. However, it made telling different pills from others much easier; it's a lot easier to spot that important bright pink pill out the plethora of boring chalky white ones. As pills became the drug delivery mechanism of choice, colour began to be used to differentiate prescription pills from those you could buy over the counter. While that generally still holds true today, there are quite a lot of branded pills these days that use colour as part of their image, from the packet down to the capsule, complete with the company logo stamped on the side. A good example of that kind of thing is Nurofen, which is actually just ibuprofen wrapped up in a fancy casing, and has that striking red branding plastered all over it. Or, of course, those little blue pills that everyone seems to able to remember -- do you think Viagra would be such a household name if the tablets weren't blue?

So there you have it. Pills come in different shapes and sizes, mainly because of where they're meant to end up inside you, and they're all an assortment of pretty colours because it makes them easier to spot and remember. Now, pass the panadol will ya? I've got a monster of a headache.

Image credit: Capsules and Pills from Shutterstock

Why Some Pills Are Little White Discs and Others Are Big Red TorpedoesThis week, our sister-site Gizmodo UK is celebrating the many facets of modern design, with a design theme week.

WATCH MORE: Science & Health News


    Just a side note on those colors. Yes it looks pretty and we can remember easily which pill is what.
    But some pills that are coated with color can have averse reactions to some people.
    My friend uses a pill called Parnate and is bright red, roughly 0.7 mm in diameter. (like a small m&m) However she washes the color off of them first in a tea strainer, because the dye they used
    causes hyperactivity and is an adverse reaction to why she has to take it. The pill inside is actually white, and shrinks roughly 0.4 mm size when u wash the colors off.
    That is one THICK layer of coloring if you ask me.

    Do pills really need that much coloring?

      It isnt the colouring thats important but the coating itself. The thicker coating may have to do with the delivery of the actual medication. It affect how fast the medicine is delivered and where it needs to be delivered. I would speak to the manufacturer before washing the tablet as she may not be getting the full dose. There may be an alternative tablet that does not have the colouring.

      I very much doubt you could wash the colour off a pill that is 0.7 mm in diameter that wouldn't be much bigger than your average grain of sand.

    i remember when "purple-speckled" was a household name.

    Can you explain why they are so large? The active ingredients in paracetamol tablets is like 500mg, the tablet must weigh more than that? It looks like it is mostly filler material, and only a little of it is the actual active ingredient. Why can't we have super tiny tablets to make it easier to swallow? Having tinier tablets would also make it cheaper to package and transport.

    Last edited 23/10/12 11:21 am

      it's also probably delivery method - it might not be safe to get that entire 500mg at once. The packing agent slowly dissolves, releasing the active ingredient slowly. Just guessing though.

      Most of the pill is excipient, things like preservatives, fillers, binders, granulating agents etc. It's easier to ensure homogeneity in the larger pills than in smaller pills. Microdose tablets (the small ones) are considered risky and only made when other tablets won't suit the intended purpose.

      so grandma can see them with her bad eyesight and pick them up with arthritic hands

      a 500mg dose of Paracetamol resting on the lining of your stomach even for a short time will do damage. It has to be diluted with packaging so that the pure paracetamol doesn't come into contact with your stomach lining for too long. Also a 500mg tablet would be tiny. alot of people would not be able to get them out of the blister packaging.

    Apart from being easier to swallow, this doesn't explain to me why you can get Panadol in both capsule and tablet form. Is Panadol supposed to last past the stomach or not?

      It does explain: the capsules are easier to swallow, but the casing is thin enough to dissolve instantly in contact with stomach acide, in much the same way as a pill...

        Read it again - the caplets don't have a protective coating, the capsules do. Panadol comes in 3 types - pills, caplets, capsules. Which is why it doesn't make sense - capsules are for the lower digestive tract, the shell protects it from the stomach - but why is Panadol in two targeted types?

          Technically speaking, paracetamol tablets are available in tablet, capsules, "caplet" and controlled release tablets in Australia. Pills are no longer the norm which were more of a paste product produced by the pharmacist and replaced by tablets due to their convenience. There are actually multiple forms of capsules, and the paracetamol capsules are actually acid dissolvable and not enterically coated to allow them dissolve in the stomach and have a quick action effect. I'd hate to have to wait 3 hours to get rid of a headache.

Join the discussion!

Trending Stories Right Now