Calcium Hydroxide Topical Solution
If you find any inaccurate information, please let us know by providing your feedback here
Tóm tắt nội dung
This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition
Issued and maintained by the United States Pharmacopeial Convention (USP)
Calcium Hydroxide Topical Solution is a solution containing, in each 100 mL, not less than 140 mg of calcium hydroxide [Ca(OH)2].
Prepare Calcium Hydroxide Topical Solution as follows (see Pharmaceutical Compounding—Nonsterile Preparations 〈795〉):
| Calcium Hydroxide | 3g |
| Purified Water | 1000 mL |
Add the Calcium Hydroxide to 1000 mL of cool Puriffed Water, and agitate the mixture vigorously and repeatedly during 1 hour. Allow the excess calcium hydroxide to settle. Dispense only the clear supernatant. [Note—The solubility of calcium hydroxide, which varies with the temperature at which the solution is stored, is about 170 mg per 100 mL at 15° and less at a higher temperature. The offcial concentration is based upon a temperature of 25°.]
The undissolved portion of the mixture is not suitable for preparing additional quantities of Calcium Hydroxide Topical Solution.
Packaging and storage—Preserve in well-filled, tight containers, at a temperature not exceeding 25°.
1 Identification
A: It absorbs carbon dioxide from the air, a
lm of calcium carbonate forming on the surface of the liquid.
B: When heated, it becomes turbid, owing to the separation of calcium hydroxide.
C: It responds to the tests for Calcium 〈191〉.
Alkalies and their carbonates—A portion of it, saturated with carbon dioxide and subsequently boiled, is neutral in reaction.
2 Assay
Pipet 100 mL of Topical Solution into a suitable container, add 50 mL of water, 15 mL of 1 N sodium hydroxide, and 300 mg of hydroxy naphthol blue, and titrate with 0.05 M edetate disodium VS to a blue endpoint. Each mL of 0.05 M edetate disodium is equivalent to 3.705 mg of calcium hydroxide [Ca(OH)2].
