Final answer:
An SNDA is a submission to the FDA for changes to an already-approved drug, ensuring ongoing safety and efficacy after modifications. It pertains to changes in formulation, labeling, or expanded drug indications. The FDA's review of an SNDA ensures public safety and maintains drug quality.
Step-by-step explanation:
An SNDA (Supplemental New Drug Application) is a submission to the Food and Drug Administration (FDA) by the manufacturer of a drug that has already been approved via a New Drug Application (NDA). This submission is required when a drug maker wants to make changes to a drug such as its formulation, labeling, or manufacturing process. An SNDA is also necessary for expanding the drug's indications, or for making any significant change that could affect its safety, efficacy, or quality.
The original NDA process is comprehensive and requires substantial evidence of the drug's safety and efficacy, obtained through preclinical and clinical trials. Once the drug is approved and on the market, any significant modifications necessitate a review by the FDA through the SNDA process. This ensures that changes do not compromise the drug’s approved use and that it continues to meet the agency's strict requirements for public safety.
Additionally, the SNDA allows the FDA to reassess the drug's therapeutic equivalence and validate that it remains safe and effective following any adjustments made by the manufacturer. This process maintains the integrity and quality of pharmaceuticals available to consumers and healthcare professionals.