Terpin Hydrate Oral Solution

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

DOWNLOAD PDF HERE

1 DEFINITION

Terpin Hydrate Oral Solution contains, in each 100 mL, NLT 1.53 g and NMT 1.87 g of terpin hydrate (C₁₀H₂₀O₂ · H₂O).

2 ASSAY

Procedure

Internal standard solution: 20 mg/mL of biphenyl in chloroform

Standard solution: Transfer 170 mg of USP Terpin Hydrate RS to a 100-mL volumetric flask, dissolve in 5 mL of alcohol, add 5.0 mL of Internal standard solution, and dilute with chloroform to volume.

Sample solution: Pipet 10 mL of Oral Solution into a separator. Add 20 mL of water and 10 mL of 5 N sodium hydroxide, and extract with three 25-mL portions of chloroform, filtering each, successively, through cotton. Rinse the cotton with chloroform. To the combined rinse and extracts add 5.0 mL of Internal standard solution.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: GC

Detector: Flame ionization

Column: 3.5-mm × 1.2-m glass; packed with 6% G1 on support S1A

Temperatures

Injection port: 260°

Detector: 260°

Column: 120°

Carrier gas: Nitrogen

Flow rate: Necessary to yield approximate retention times of 7 min for terpin and 11 min for biphenyl

Injection volume: 1 μL

System suitability

Sample: Standard solution

Suitability requirements

Resolution: NLT 2.0 between the terpin and biphenyl peaks

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the amount of terpin hydrate (C₁₀H₂₀O₂ · H₂O) in 100 mL of Oral Solution taken:

Result = (R_U/R_S) × W_S × V

R_U = peak response ratio of terpin to biphenyl from the Sample solution

R_S = peak response ratio of terpin to biphenyl from the Standard solution

W_S = weight of USP Terpin Hydrate RS, calculated on the anhydrous basis (g)

V = volume of sample, 10 mL

Acceptance criteria: 1.53–1.87 g

3 SPECIFIC TESTS

Alcohol Determination, Method II 〈611〉 : 90.0%–110.0% of the labeled amount of C₂H₅OH

4 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers.

USP Reference Standards 〈11〉

USP Terpin Hydrate RS