Your Medication May Not Be Dissolving Properly

Valisure’s testing of ibuprofen with real-world conditions reveals significant issues.

The effectiveness of any medication depends on the drug being able to correctly dissolve in the fluids of the gastrointestinal tract prior to being absorbed into the circulatory system. Various ingredients and different formulations of a pill can affect drug dissolution time or bioavailability, which is the degree and rate at which an administered drug is absorbed by your body. Poor formulations can lead to lack of efficacy or adverse effects. One famous example was when Wellbutrin went generic, which resulted in so many thousands of complaints that regulators performed their own tests. The findings revealed that the generics were dissolving so differently from the original brand that the effect of the drug was not equivalent. Consequently, those generics were pulled from the market. This instance underscores the importance to test the dissolution of medications and to do so under the conditions that mimic your stomach and intestinal track. However, drugs aren’t always tested using these kinds of real-world conditions and sometimes the comparison can reveal dramatic differences. Common over-the-counter drug in caplet form. Twelve caplets from each bottle were tested using two different protocols (see Figure 1).

Six caplets from each bottle were tested using the industry standard protocol for dissolution with a neutral pH of 7.2. Using this standard, all caplets dissolved within the allotted two-hour window. However, your stomach has a resting pH of roughly 1.2. The industry standard using a pH of 7.2 is much closer to the pH of water which is about 1,000,000 times less acidic than your stomach. All the drugs passed when tested with the industry standard of 1,000,000 times less acidic conditions.

Pharmaceutical companies are actually the ones that set the testing standards which can be different for each drug even though the conditions in the average human stomach rarely change. In some cases, these standards do not accurately reflect the real-world conditions of what’s happening in your body.

Valisure tested the same medication using our own dissolution protocol that follows real-world conditions and our method yielded dramatically different results. For this particular test, Valisure used a simulated stomach fluid with a pH of 1.2 for two hours and then switched to simulated intestine fluid with a pH of 6.8 for as many hours as needed for the pill to dissolve completely. Using the Valisure dissolution protocol, we uncovered extreme variability in the dissolution time and some of the pills didn’t dissolve even after over 15 hours of testing. (see Figure 2).

The extreme variability in the caplets Valisure analyzed suggests that consumers may not always experience the intended therapeutic effects of a medication because the industry standard tests do not accurately replicate the naturally-occurring conditions in the human body.


Figure 1.
Do medications dissolve appropriately for consumers? Six different bottles of the same ibuprofen were tested using the industry standard dissolution protocol and the Valisure dissolution protocol that follows real-world conditions.

Table 1. Two out of six bottles of ibuprofen failed the Valisure Dissolution Test. The average time in minutes it takes for six caplets from each bottle to dissolve. A) All caplets dissolved in the standard protocol at neutral pH and passed. B) Two bottles of medications failed Valisure’s protocol to dissolve in conditions that simulate acidic stomach fluid (120 minutes) followed by less acidic intestinal fluid, which simulates a caplet’s transition from the stomach to the intestine.

Figure 2: The Valisure dissolution protocol reveals dramatic medicine variability. It takes greater than 24 hours for some caplets from bottle 4 to fully dissolve. This test was repeated and the caplets above show two, four, six and eight hours of dissolution testing.

At Valisure, we analyze multiple samples of medications from each batch and reject the medications that fail to meet our own rigorous testing standards. These results underscore the importance of testing each medication’s quality at the pharmacy, a process that, in the US, only Valisure’s pharmacy performs.

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