FDA warns Glenmark for failure to investigate dissolution failures
Glenmark Pharmaceuticals is once again under scrutiny from the US Food and Drug Administration (FDA) due to violations of good manufacturing practices (GMP). The issues are related to an investigation that found the company’s extended-release potassium chloride tablets did not dissolve properly. Additionally, the company failed to conduct stability testing and did not validate its testing methods.The company’s site in Madhya Pradesh, India, was inspected in early to mid-February. The warning letter was published on FDA’s website on 22 July.
The company was reprimanded for failing to conduct a proper investigation into the tablets' inability to dissolve during stability testing. The firms attributed the failure to particles in the active pharmaceutical ingredient (API), but this explanation was insufficient. FDA said Glenmark has a process control in place to control the particle sizes in the API.
Glenmark also identified a process change implemented in 2021, aimed at adjusting the content of a solution, as a contributing factor to the failure. However, the FDA rejected this explanation, stating that it lacked the necessary scientific evidence to substantiate it as the root cause.
In June 2025, Glenmark announced a voluntary recall of its potassium chloride extended release tablets due to an inability of the tablets to dissolve properly. These medicines are used to treat patient with low potassium levels.
FDA also chastised the company for its failure to conduct stability testing program for its drug products in a timely manner. FDA said that “stability testing was overdue by 3 months or longer for a large proportion of your samples.”
Agency investigators also found Glenmark did not validate and transfer test methods to ensure products were suitable for their intended use. FDA said that “method validation and verification studies are necessary to support reliable determination of identity, strength, quality, purity, and potency of drugs. Without evaluating the validity of methods, you lack the basic assurance that your laboratory data accurately reflects drug product quality.”
FDA advised the company to consult its guidance on analytical procedures and methods validation, as well as the ICH Q2(R2) guideline on validation of analytic procedures for general principles and approaches for method validation.
The agency said Glenmark is a repeat offender and that “similar” GMP problems have been found by FDA inspectors at multiple sites within the company’s network.
These include a warning letter sent to its site in Himachal Pradesh in October 2019 for similar GMP violations, and to its site in Goa, India, in 2022 for inadequate testing. The company also received a warning letter in June 2023 related to its North Carolina facility. (RELATED: FDA Warns India, Bahamian Drugmakers, Regulatory Focus 15 October 2019; FDA warns Glenmark over GMP, laboratory control issues, Regulatory Focus 6 December 2022)
“These repeated failures at multiple sites demonstrate that management oversight and control over the manufacture of drugs is inadequate.”
Glenmark said it would cease producing potassium chloride ER capsules and suspend making these products in its facility for the US market. The FDA advised the company to hire a consultant.
Glenmark has 15 days to respond to the agency.
Warning letter
