Starch TS
If you find any inaccurate information, please let us know by providing your feedback here
This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition
Issued and maintained by the United States Pharmacopeial Convention (USP)
Prepare this solution by one of the following procedures. Apply the Test for sensitivity to confirm suitability for freshly or previously prepared solutions or commercially bought solutions. (ERR 1-Sep-2023)
Procedure with Salicylic Acid as Preservative
Bring about 95 mL of water to a boil. Mix 1 g of soluble starch with 5 (ERR 1-Sep-2023) mL of cold water to make a thin paste and, while stirring, add the boiling water. Boil for 1 min with continous stirring, cool, and add 100 mg of salicylic acid and mix until dissolved.
Storage: If use beyond the day of preparation is required, the solution shall be stored under refrigeration. (ERR 1-Sep-2023) If stored under refrigeration, the starch solution is stable for about 2–3 weeks.
Procedure with Red Mercuric Iodide as Preservative
Bring about 95 mL of water to a boil. Mix 1 g of soluble starch with 10 mg of red mercuric iodide and 5 mL of cold water to make a thin paste and, while stirring, add the boiling water. Boil for 1 min with continuous stirring. Cool, and use only the clear solution.
Procedure with No Preservative
Bring about 95 mL of water to a boil. Mix 1.0 g of soluble starch with 5 mL of cold water to make a thin paste and, while stirring, add the boiling water. Boil for 1 min with continuous stirring and cool. Use only a freshly prepared solution. (ERR 1-Sep-2023)
Test for sensitivity: Transfer 10.0 mL of 0.1 N Iodine VS to a 100-mL volumetric flask, add 0.6 g of potassium iodide and dilute with water to volume. Prepare this solution immediately before use. Add 0.05 mL of this preparation and about 50 mg of potassium iodide to a mixture of 1mL of the starch solution and 20 mL of water. The solution is blue.
[Note—Commercially available starch solutions may be used; including mercury-free solutions or those containing alternative preservatives.
(ERR 1-Sep-2023) ]
