Class I Methods: Which statement is correct regarding isotonicity adjustment methods?

• A. ALL statements are correct
• B. Only ONE statement is correct
• C. TWO statements are correct
• D. THREE statements are correct

Answer: (A)

Isotonicity adjustment means making a preparation have the same osmotic pressure as body fluids, so it won’t irritate or damage tissues. In Class I methods, there isn’t just one way to achieve that; you typically have several valid approaches. You can dial in the right amount of an osmotically active solute, like sodium chloride or dextrose, to reach the target osmolarity. You can use an isotonic diluent or vehicle and adjust the final volume to hit the same osmotic level. You may also verify the final product with an osmometer or by appropriate osmolarity tests to ensure it’s within acceptable ranges. Because these are all standard, legitimate ways to achieve isotonicity and checks to confirm it, the option stating that all statements are correct best matches how isotonicity adjustment methods are actually used.