Lecture 02

• What is the assay in drug manufacture?

  A quantitative test
• Why is the assay important in drug manufacture?

  It ensures the correct dosage of active ingredients
• Where can the assay test be found?

  In the British Pharmacopoeia
• What is the choice of analytical method for assay based on?

  It depends on the specific requirements of the analysis
• What does the assay define in pharmaceutical analysis?

  Quantitative determination of an analyte
• What is included in each monograph in the BP for API?

  Procedure to measure content and acceptable limits
• What is the acceptable content range for naproxen as an API?

  99.0% to 101.0%
• Why is it important to know the API content in drug substances?

  To ensure proper dosage and efficacy
• How can we have more than 100% API content?

  Due to measurement uncertainties and water
• What does the assay measure regarding purity?

  It indicates the level of impurities present
• What types of impurities does the assay not account for?

  Insoluble and invisible impurities
• What is the acceptable content range for naproxen in formulated products?

  95.0% to 105.0% of the stated amount
• Why is the margin for formulated products larger?

  Due to the presence of other excipients
• What is the role of a Controlled Reference Standard (CRS)?

  It is a pure sample of a compound
• What are the types of CRS mentioned?

  EPCRS, BPCRS, and USP Reference Standards
• When must CRS be used in analysis?

  If specified in a monograph
• What are the most popular analytical techniques for assays?

  HPLC, UV, and Titration
• What is the principle of UV analysis?

  Signal is proportional to the amount present
• What must be done during sample preparation for UV analysis?

  Remove interference from excipients
• How is the amount calculated in UV analysis?

  According to Beer’s law or comparison with CRS
• What is HPLC used for in assays?

  It separates a mixture into individual components
• How is the content of API determined in HPLC?

  By calibrating with a CRS solution
• What is required for titration to be effective?

  A reaction specific for the API
• How is the % w/w content of anhydrous Ephedrine determined?

  By acid-base titration