Perhitungan Media Disolusi 1 2

𝕸𝖆𝖘 𝕬𝖓𝖉𝖞 𝕯𝖎𝖌𝖎𝖙𝖆𝖑 𝕸𝖊𝖉𝖎𝖆

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Apr 11, 2025

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Complete Recipe: Dissolution Media Calculations for 1:2 Media

Dissolution testing is a critical pharmaceutical quality control procedure. Accurate preparation of dissolution media is paramount to obtaining reliable and reproducible results. This article provides a complete recipe and detailed calculations for preparing a common dissolution media ratio: 1:2. This typically refers to a 1:2 ratio of 0.1N HCl: Phosphate Buffer pH 6.8. However, the principles detailed here are adaptable to other media ratios.

Understanding the 1:2 Ratio

The 1:2 ratio signifies a mixture where one volume of 0.1N hydrochloric acid (HCl) is mixed with two volumes of phosphate buffer pH 6.8. This creates a media with a pH that falls between the pH of the individual solutions – a controlled environment crucial for drug dissolution.

Materials Required:

• 0.1N Hydrochloric Acid (HCl): Prepared according to USP standards. (Detailed preparation protocols are readily available in pharmacopoeias and official compendia.)
• Phosphate Buffer pH 6.8: This buffer solution needs to be prepared according to the USP. You'll need monobasic potassium phosphate (KH₂PO₄) and dibasic sodium phosphate (Na₂HPO₄). The exact masses of each required depend on the desired volume and the buffer’s specific formulation. Again, the USP provides detailed instructions.
• Volumetric Flasks: Choose appropriate sizes to ensure accurate dilutions.
• Graduated Cylinders or Pipettes: For precise volume measurements.
• Magnetic Stirrer and Stir Bar: For thorough mixing.
• pH Meter: To verify the final pH of the prepared media.

Calculations for Preparing 1000mL (1L) of 1:2 Dissolution Media

The 1:2 ratio dictates that the total volume is divided into three parts: one part 0.1N HCl and two parts phosphate buffer pH 6.8.

1. Total Volume: We are preparing 1000mL (1L) of dissolution media.

2. Volume of 0.1N HCl: This is one-third of the total volume: 1000mL / 3 = 333.33mL (approximately). Round this to a practical volume, keeping accurate measurement in mind (e.g., 333.3 mL).

3. Volume of Phosphate Buffer pH 6.8: This is two-thirds of the total volume: (1000mL / 3) * 2 = 666.67mL (approximately). Round this, again considering precise measurement (e.g., 666.7 mL).

4. Verification: 333.3 mL + 666.7 mL = 1000 mL (Slight variations due to rounding are acceptable).

Preparation Procedure:

1. Prepare the 0.1N HCl and Phosphate Buffer pH 6.8 solutions separately, following the detailed procedure outlined in your chosen pharmacopoeia. Ensure they are both at room temperature.

2. Measure the volumes calculated above, using the appropriate measuring instruments.

3. Add the 0.1N HCl to a clean, 1000mL volumetric flask.

4. Add the phosphate buffer pH 6.8.

5. Mix thoroughly using a magnetic stirrer for at least 15 minutes to ensure a homogenous solution.

6. Verify the pH using a calibrated pH meter. The resulting pH should fall within an acceptable range for the specific requirements of the test.

Important Considerations:

• Accuracy: Precise measurements are crucial for reliable dissolution results. Use calibrated glassware and accurately follow the preparation procedures.
• Water Quality: Use high-quality purified water for preparing both the HCl solution and the phosphate buffer.
• Temperature: Maintaining the temperature of the media is essential during dissolution testing.
• Degasification: Some dissolution media requires degassing (removing dissolved gases) prior to use. Check your specific test procedure for this requirement.

This recipe offers a detailed guide for preparing 1:2 dissolution media. Remember to always refer to the official pharmacopoeia or the specific monograph of the drug being tested for the precise requirements of the dissolution test. The accuracy of your dissolution media preparation is pivotal for achieving valid and reliable results.