FDA Issues New Warning Letter Over Continued Manufacturing Failures
The FDA has again flagged Glenmark Pharmaceuticals for serious manufacturing violations tied to its extended-release potassium chloride capsules. This is the same product at the center of our class action, Butler v. Glenmark Pharmaceuticals Inc., USA.
On July 11, 2025, the FDA sent Glenmark Pharmaceuticals Limited a new warning letter citing ongoing violations of current good manufacturing practice (CGMP) requirements. According to the letter, Glenmark failed to properly investigate stability testing results showing that certain lots of its potassium chloride capsules did not meet dissolution specifications, meaning the drug wasn’t releasing into the body the way it was supposed to.
What the FDA Found
The warning letter identifies a pattern, not an isolated lapse:
- Glenmark did not adequately investigate test failures showing that potassium chloride capsules failed to dissolve as intended over time.
- Because of this dissolution defect, patients taking the recalled capsules may not have received the correct amount of medication throughout the dosing period.
- The FDA noted that these are repeat deficiencies. Glenmark received a similar warning letter in 2022 and, according to the FDA, has still not fully corrected the underlying systemic problems in its manufacturing process.
Why This Matters for Patients
Potassium chloride is prescribed to treat or prevent dangerously low potassium levels. When an extended-release capsule doesn’t dissolve properly, patients can end up with too little or too much of the active ingredient in their system. Too much potassium can lead to hyperkalemia, a condition that can cause irregular heartbeat and, in serious cases, cardiac arrest.
Until Glenmark resolves these issues, the FDA has indicated it may withhold approval of new applications or supplements from the facility, and further enforcement action could follow.
How This Connects to Our Case
This is the same underlying defect at the heart of Butler v. Glenmark Pharmaceuticals Inc., USA, the class action The Block Firm filed in August 2024 on behalf of consumers who purchased Glenmark’s potassium chloride extended-release capsules. That case followed a Class I recall — the FDA’s most serious recall category — of 114 batches of the drug in June 2024, after the same dissolution problem was discovered.
The July 2025 warning letter reinforces what we’ve alleged from the start: that Glenmark’s failure to meet basic manufacturing standards for this drug wasn’t a one-time mistake, but part of a pattern the company has been unable or unwilling to fix. We believe consumers who paid for potassium chloride capsules that didn’t work as promised are entitled to get their money back, and this latest FDA action only strengthens that position.
We’ll continue monitoring both the regulatory record and the litigation, and we’ll post updates here as the case develops.
If you or a loved one took potassium chloride manufactured by Glenmark, contact us today to learn whether you may be affected.
