Propylene Glycol Dicaprylate/Dicaprate
Decanoic acid, mixed diesters with octanoic acid and propylene glycol
[68583-51-7].
(proe' pi leen glye' kol dye kap' ri late/dye kap' roe ate).
Decanoic acid, mixed diesters with octanoic acid and propylene glycol
[68583-51-7].DEFINITION
Propylene Glycol Dicaprylate/Dicaprate is a mixture of the propylene glycol mono- and diesters of caprylic acid (C8H16O2) and capric acid (C10H20O2), the diesters fraction being predominant.
IDENTIFICATION
• B. Thin-Layer Chromatography Identification Test 
201
201
Standard solution:
50 mg/mL of USP Propylene Glycol Dicaprylate/Dicaprate RS in methylene chloride
Sample solution:
50 mg/mL of Propylene Glycol Dicaprylate/Dicaprate in methylene chloride
Application volume:
10 µL, as streaks
Developing solvent system:
Ether and hexane (7:3)
Spray reagent:
0.1 mg/mL of rhodamine 6G in alcohol
Analysis
Samples:
Standard solution and Sample solution
Develop the chromatogram over a path of 15 cm, and dry the plate in a current of air. Spray the plate with Spray reagent, and locate the spots on the plate by examination under UV light at a wavelength of 365 nm.
Acceptance criteria:
The RF values of the principal spots from the Sample solution correspond to those from the Standard solution.
• C.
It meets the requirements of the test for Fats and Fixed Oils 401, Fatty Acid Composition.
401, Fatty Acid Composition.
IMPURITIES
Inorganic Impurities
• Articles of Botanical Origin, Total Ash 561:
NMT 0.1%
561:
NMT 0.1%
• Alkaline Impurities
Sample:
2.0 g of Propylene Glycol Dicaprylate/Dicaprate
Analysis:
Dissolve the Sample in a mixture of 1.5 mL of alcohol and 3.0 mL of ether. Add 0.05 mL of bromophenol blue TS.
Acceptance criteria:
NMT 0.15 mL of 0.01 N hydrochloric acid is required in order to change the color of the indicator to yellow.
SPECIFIC TESTS
• Fats and Fixed Oils, Acid Value 401:
NMT 0.2
401:
NMT 0.2
• Fats and Fixed Oils, Fatty Acid Composition 401:
Propylene Glycol Dicaprylate/Dicaprate exhibits the composition profile of fatty acids shown in the following table:
401:
Propylene Glycol Dicaprylate/Dicaprate exhibits the composition profile of fatty acids shown in the following table:
| Carbon-Chain Length | Number of Double Bonds |
Percentage (%) |
|---|---|---|
| 6 | 0 |  2.0 |
| 8 | 0 | 50.0–80.0 |
| 10 | 0 | 20.0–50.0 |
| 12 | 0 | 3.0 |
| 14 | 0 | 1.0 |
• Fats and Fixed Oils, Hydroxyl Value 401:
NMT 10
401:
NMT 10
• Fats and Fixed Oils, Iodine Value 401:
NMT 1.0
401:
NMT 1.0
• Fats and Fixed Oils, Peroxide Value 401:
NMT 1.0
401:
NMT 1.0
• Fats and Fixed Oils, Unsaponifiable Matter 401:
NMT 0.5%, determined on 5.0 g
401:
NMT 0.5%, determined on 5.0 g
• Water Determination, Method Ia 921:
NMT 0.1%, using a mixture of methanol and methylene chloride (1:1) in place of methanol in the titration vessel
921:
NMT 0.1%, using a mixture of methanol and methylene chloride (1:1) in place of methanol in the titration vessel
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in well-closed containers, and protect from moisture. No storage requirements specified.
• USP Reference Standards 11
11
USP Propylene Glycol Dicaprylate/Dicaprate RS
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Robert H. Lafaver, M.S.
Scientific Liaison 1-301-816-8335 |
(EXC2010) Monographs - Excipients |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 1933
Pharmacopeial Forum: Volume No. 36(5) Page 1236