Acetyltributyl Citrate

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

Acetyltributyl Citrate contains NLT 99.0% of C H O , calculated on the anhydrous basis.

2 IDENTIFICATION

Change to read:

• A. SPECTROSCOPIC IDENTIFICATION TESTS 〈197〉 , Infrared Spectroscopy : 197F (CN 1-MAY-2020)
• B. The retention time of the Sample solution corresponds to that of a similar preparation of USP Acetyltributyl Citrate RS, as obtained in the Assay.

3 ASSAY

3.1 PROCEDURE

System suitability solution: 30 mg/mL each of USP Acetyltributyl Citrate RS and USP Tributyl Citrate RS in toluene Sample solution: 30 mg/mL of Acetyltributyl Citrate in toluene

Chromatographic system

(See Chromatography 〈621〉, System Suitability.) Mode: GC

Detector: Flame ionization

Column: 0.32-mm × 30-m, bonded with a 0.5-µm layer of phase G42 Temperature

Injector: 240°

Detector: 280°

Column: See the temperature program table below.

Flow rate: 1.9 mL/min Carrier gas: Helium Injection type: Split, 30:1 Injection size: 1 µL

System suitability

Sample: System suitability solution

[NOTE—The relative retention times for tributyl citrate and acetyl tributyl citrate are 0.9 and 1.0, respectively.] Suitability requirements

Resolution: NLT 1.5 between tributyl citrate and acetyl tributyl citrate

Relative standard deviation: NMT 2.0% determined from both the tributyl citrate and acetyl tributyl citrate peaks, based on area percent calculation

4 Analysis

Sample: Sample solution

[NOTE—Measure all of the peak areas, excluding the solvent peak.]

Calculate the percentage of C₂₀H₃₄O₈ in the portion of Acetyltributyl Citrate taken:

Result = (r_u /r_t ) ×100

r_u = peak area of the Sample solution

r_t = sum of all the peak areas

Acceptance criteria: NLT 99.0% on the anhydrous basis

5 SPECIFIC TESTS

SPECIFIC GRAVITY 〈841〉: 1.045–1.055

REFRACTIVE INDEX 〈831〉: 1.4410–1.4425

ACIDITY

• Neutralized isopropyl alcohol: To a suitable quantity of isopropyl alcohol add 2–3 drops of bromothymol blue TS and just sufficient 0.10 N sodium hydroxide dropwise to produce a faint blue color. [NOTE—Prepare Neutralized isopropyl alcohol just before use.]
• Sample solution: 32.0 g of Acetyltributyl Citrate in 30 mL of Neutralized isopropyl alcohol
• Analysis: Add bromothymol blue TS. Titrate with 0.10 N sodium hydroxide to a faint blue endpoint. Acceptance criteria: NMT 1.0 mL of 0.10 N sodium hydroxide is required.

WATER DETERMINATION, Method I 〈921〉: NMT 0.25%

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight containers.

USP REFERENCE STANDARDS 〈11〉

• USP Acetyltributyl Citrate RS
• USP Tributyl Citrate RS