Dibutyl Sebacate

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition
Issued and maintained by the United States Pharmacopeial Convention (USP)
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1 DEFINITION

Dibutyl Sebacate consists of esters of n-butyl alcohol and saturated dibasic acids, principally sebacic acid. It contains NLT 92.0% and NMT 102.0% of dibutyl sebacate (C₁₈H₃₄O₄).

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197F (CN 1-May-2020)

Sample: Undried specimen

Acceptance criteria: Meets the requirements

B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

Procedure

Internal standard solution: 0.9 mg/mL of methyl heptadecanoate in alcohol

Standard solution: 1.0 mg/mL of USP Dibutyl Sebacate RS in the Internal standard solution

Sample solution: 1.0 mg/mL of Dibutyl Sebacate in the Internal standard solution

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: GC

Detector: Flame ionization

Column: 0.32-mm × 30-m fused silica column, coated with a 0.25-μm

lm of phase G2

Temperature

Detector: 300°

Injection port: 300°

Column: See Table 1.

Table 1

Carrier gas: Helium

Linear velocity: 50 cm/s

Injection volume: 1 μL

Injection type: Split injection, split ratio is about 30:1

Run time: 20 min

System suitability

Sample: Standard solution

[Note—The relative retention times for dibutyl sebacate and methyl heptadecanoate are 1.0 and 0.9, respectively.]

Suitability requirements

Resolution: NLT 2.0 between methyl heptadecanoate and dibutyl sebacate

Relative standard deviation: NMT 2.0% for the peak response ratio of dibutyl sebacate to methyl heptadecanoate

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of dibutyl sebacate (C₁₈H₃₄O₄) in the portion of Dibutyl Sebacate taken:

Result = (R_U/R_S) × (C_S/C_U) × 100

R_U= peak response ratio of dibutyl sebacate to methyl heptadecanoate from the Sample solution

R_S= peak response ratio of dibutyl sebacate to methyl heptadecanoate from the Standard solution

C_S= concentration of USP Dibutyl Sebacate RS in the Standard solution (mg/mL)

C_U= concentration of Dibutyl Sebacate in the Sample solution (mg/mL)

Acceptance criteria: 92.0%–102.0%

4 SPECIFIC TESTS

Specific Gravity 〈841〉: 0.935–0.939 at 20°

Refractive Index 〈831〉: 1.429–1.441

Fats and Fixed Oils, Acid Value 〈401〉: NMT 0.1

Fats and Fixed Oils, Saponification Value 〈401〉: 352–360

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers. Store at room temperature. Protect from moisture.

USP Reference Standards 〈11〉

USP Dibutyl Sebacate RS