Why are these pills the same size?

December 1, 2011 7:17 AM

Why are these pills smaller than I expected?

Last night, after several hours of chest pain that didn't seem to be heartburn, I went to the hospital. I didn't have a heart attack (yay!), instead they diagnosed me some sort of inflammation of the cartilage in my chest and sent me home with a prescription for 600 MG ibuprofen tablets.

The ibuprofen I normally take for headaches and the like (Liquid gels) are listed at 200 MG, but the size doesn't look that different from the 600 MG tablets to me. It's bigger, but it's not 3X bigger.

Why is this? Are Liquid Gels just bigger than tablets for some reason? Or am I just bad at judging size?

posted by Bulgaroktonos to health & fitness (7 answers total)

Yes, liquid gels are bigger, as they have water (or some other liquid) in them, where the tablets do not.
posted by Grither at 7:21 AM on December 1, 2011

Nice to know, I totally should have thought of that.
posted by Bulgaroktonos at 7:25 AM on December 1, 2011

Also, note that a large part of the bulk in any tablet is going to be inactive ingredients (fillers, binders, etc.) So the same size tablet can still contain a much larger dose of the drug, just by reducing the amount of binder slightly.

My go-to example for this is synthroid, where the dose size is tiny, measured in micrograms -- the tablets for different doses are all exactly the same size, and are distinguished by color and markings.
posted by McCoy Pauley at 7:29 AM on December 1, 2011 [1 favorite]

Ibuprofen or (RS)-2-(4-(2-methylpropyl)phenyl)propanoic acid would not make a great pill in its pure form, it has to be stabilized by fillers. If you are really curious, and have a scale, you can measure the g/g purity of the tablets by comparing their total mass to the listed dose in them.

The liquid tablets are likely not water, the chemical structure looks like it wouldn't be very soluble in water at all, but your tablet likely contains carbonated water or a water/alcohol mixture.
posted by Blasdelb at 7:29 AM on December 1, 2011

IANAP, but I guess a couple of factors are at play here:

1) Tablets have excipients, inactive ingredients. Excipients are not counted in your mg dosage of active ingredient.

2) A psychological effect where humans are bad at judging volume because it increases with the cube of any one dimension. For example, the radius of a 200ml sphere is about 3.6mm, and the volume of a 600ml sphere is about 5.2mm, nowhere near 3x the 'size'.
posted by cogat at 7:35 AM on December 1, 2011

Let me try 2) again:

2) A psychological effect where humans are bad at judging volume because it increases as a cube of the increase in any one dimension. For example, the radius of a 200ml sphere is about 3.6mm, and the radius of a 600ml sphere is about 5.2mm, which looks like nowhere near '3x the size'.
posted by cogat at 7:37 AM on December 1, 2011

In my organic chem lab in college we took several over the counter drugs (advil, tylenol, etc) in different strengths and did something (I was bad at o-chem) to them to distill out the active ingredient.

Most of the pills are, as others mention above, inactive ingredients like starches and binders. The actual amount of drug in your average tablet is staggeringly small. They make them bigger so they're easier to see and hold, and so they can add colors and stamps to visually distinguish brands and dosage size.

The only time the fillers really matter is on time release tablets, because those are meant to break down at different speeds and leach out the active drug slowly.
posted by phunniemee at 7:51 AM on December 1, 2011