Montelukast EP Impurity E is primarily used in the pharmaceutical industry as a reference standard during the quality control and analytical testing of Montelukast, a drug commonly prescribed for asthma and allergy management. Its application ensures the identification, quantification, and monitoring of impurities in Montelukast formulations, which is critical for maintaining the drug's safety, efficacy, and compliance with regulatory standards. By utilizing this impurity standard, manufacturers can validate analytical methods, assess batch consistency, and ensure the purity of the final pharmaceutical product. This contributes to the overall quality assurance process in drug production.