How Much Oxycodone is in a 10 mg Oxycodone Hydrochloride Tablet?

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If I understand your question correctly, the pharmacy manager told you that your 10 mg oxycodone tablet (NDC 31722-0485-01) holds only 7.82 mg of oxycodone, and the price gap compared with brand-name products has you wondering what you are really getting.

A standard 10 mg oxycodone tablet does contain 10 mg of oxycodone hydrochloride, but that is a salt form of oxycodone. The actual amount of base oxycodone is less than that. For a 10 mg dose of oxycodone hydrochloride, that works out to 8.9637 mg of the oxycodone molecule itself. I couldn't tell you where the 7.82 mg figure the manager told you comes from, as that does not match any figure I recognize for this strength.

Also, for the second part of your question, the lower price of a generic has nothing to do with there being less medicine in the tablet. It's really just based on the economics of the pharmacy world.

Why a 10 mg Oxycodone Tablet Holds About 9 mg of Oxycodone

Oxycodone is made into tablets as a salt, oxycodone hydrochloride, because the salt form dissolves well and is stable on the shelf.

The hydrochloride part adds a little weight of its own, about ten percent, so when a label says 10 mg, it is describing the weight of oxycodone hydrochloride, and the oxycodone portion inside that salt comes to just under 9 mg.

Many oxycodone labels print both numbers side by side for exactly this reason, listing the hydrochloride strength and then the smaller amount of oxycodone it is equivalent to. Nearly every oxycodone product in the United States, generic or brand, immediate-release or long-acting, follows this same salt-based convention, which is why a prescription for 10 mg means the same thing no matter which manufacturer fills it.

If you look at the prescribing information for many oxycodone products, they do actually list the exact amount of oxycodone base in the product (here is an example: dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=4197ffc5-22f5-01f4-e054-00144ff88e88&type=display). This example states: *10 mg oxycodone HCl is equivalent to 8.9637 mg of oxycodone.

If you want to get into the numbers, and calculate the amount of base oxycodone in oxycodone hydrochloride, you do so by comparing the molecular mass of each:

• Molecular weight Oxycodone base: 315.36 g/mol
• Molecular weight Oxycodone hydrochloride: 351.82 g/mol

10 mg * (315.36/351.82) = 8.96 mg.

Now, there are exceptions to how some oxycodone hydrochloride products are labeled.

The one well-known exception is Xtampza ER, a brand-name extended-release capsule that is labeled by the weight of oxycodone itself rather than the salt, so its capsules carry strengths like 9 mg, 13.5 mg, and 36 mg.

Its own labeling spells out the conversion, noting that a 36 mg capsule is equivalent to 40 mg of oxycodone hydrochloride, which is the same nine-to-ten relationship at work in your tablet.

That may be where some of the confusion started, since a person could easily mix up the two labeling systems, but even under the Xtampza system a 10 mg hydrochloride tablet would be about 9 mg, not 7.82 mg.

Why Generic Oxycodone Costs So Much Less Than the Brands

Immediate-release oxycodone has been off patent for decades, and several companies make it, so competition pushes the price down to a few cents per tablet at many pharmacies.

A generic manufacturer does not have to repeat the original clinical trials or spend on marketing, yet the FDA still requires every approved generic to contain the same active ingredient in the same strength and dosage form and to deliver it into the bloodstream in essentially the same way as the brand it copies.

What differs between makers is the inactive ingredients, meaning the fillers, binders, and dyes, not the amount of oxycodone. A fourfold gap is actually modest for this drug.

Brand immediate-release products such as Roxicodone, Oxaydo, and RoxyBond carry a premium, and the long-acting brands OxyContin and Xtampza ER cost far more still because of their abuse-deterrent designs, which is a reasonable thing to pay for when a prescriber specifically wants those features but is not something a plain 10 mg tablet is meant to replace.

Final Words

Your 10 mg tablet should contain 10 mg of oxycodone hydrochloride, which is close to 9 mg of oxycodone itself, and the low price reflects generic competition rather than a weaker product.

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