Dissolution testing of an enteric coated tablets

Dissolution testing of enteric-coated tablets involves evaluating how well the tablet releases its active ingredient in a simulated gastrointestinal environment. Here’s a general procedure

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Preparation of Equipment and Solutions:

Dissolution Apparatus: Typically, a USP Type I or Type II dissolution apparatus is used.

Dissolution Medium: You need two different media:

Acidic Medium (e.g., 0.1 N HCl) to simulate the stomach environment.

Buffer Medium (e.g., phosphate buffer pH 6.8) to simulate the intestinal environment.

Pre-Test Conditions:

Ensure that the dissolution apparatus is calibrated and cleaned.

Pre-warm the dissolution medium to the appropriate temperature (usually 37°C).

Testing Procedure:

Stage 1 (Acidic Medium):

Place the enteric-coated tablets into the dissolution apparatus with the acidic medium.

Maintain the temperature at 37°C and the stirring rate as specified (often 50 or 75 rpm).

Monitor the tablet for a specified time (usually 2 hours). The tablet should remain intact and not release the drug during this period.

Stage 2 (Buffer Medium):

After the specified time in the acidic medium, transfer the tablets to the buffer medium.

Continue the dissolution process under the same conditions. Take samples at regular intervals (e.g., 15, 30, 45 minutes) and analyze them to determine the amount of drug released.

Data Analysis:

Analyze the samples using appropriate methods such as UV spectrophotometry or HPLC.

Compare the release profile with the specifications for the enteric-coated tablet.

Documentation:

Record all observations, measurements, and conditions. Ensure all results are consistent with the product specifications and regulatory requirements. The key is to mimic the conditions the tablet will encounter in the human digestive system to ensure it performs as intended.