Which of the following is a standard in vitro test for tablets that measures drug release over time?

• A. Dissolution
• B. Disintegration
• C. Content Uniformity
• D. Thickness

Answer: (A)

Dissolution testing is the standard in vitro method for tablets to measure how the drug is released over time. It uses a dissolution apparatus to place tablets in a governed medium and continuously or periodically samples the liquid to see how much drug has dissolved, producing a dissolution profile that shows the rate and extent of release. This information is crucial for predicting in vivo performance, ensuring batch consistency, and meeting regulatory quality requirements. Disintegration only measures the physical breakup of the tablet into smaller pieces and does not quantify drug release into solution. Content uniformity checks how evenly the drug is distributed among tablets, and thickness is simply a physical dimension of the dosage form.