General Test Procedure (GTP) for Solubility

PURPOSE

To lay down the procedure for the solubility of the materials

APPARATUS

Analytical balance

Stoppered test tubes - 10 ml, 20 ml & 50 ml

Conical flasks – 100 ml & 250 ml

Graduate pipettes / Bulb pipettes

REAGENTS

Freshly distilled water

Organic solvents such as methanol, ethanol, methylene chloride etc. - AR grade

PROCEDURE

• Transfer an accurately weighed sample into a glass-stoppered test tube and add a specified quantity of solvent as per the table given below.
• Shake vigorously for one minute, and keep aside for 15 minutes.
• In case, if the sample is not completely dissolved, repeat step 2.
• The term miscible is used for liquid samples and describes a sample that is miscible in all proportions with the stated solvent.

Descriptive term	Approximate volume of solvent in milliliters per gram of solute
Very soluble Freely soluble Soluble Sparingly soluble Slightly soluble Very slightly soluble Practically insoluble	Less than 1 From         1              to           10 From         10            to           30 From         30            to           100 From         100          to           1000 From        1000         to           10000 More than                               10000

REFERENCES

USP, BP and Pharmeuropa Technical Guide issued in December 1999.

Notes

1. To check the solubility for very soluble, free soluble, soluble, and sparingly soluble use 100mg to 1000mg of sample.
2. To check the solubility for slightly, very slightly, and practically insoluble use 10 mg to 100 mg of sample.

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