Propylene Glycol Dicaprylate/Dicaprate
Decanoic acid, mixed diesters with octanoic acid and propylene glycol
[68583-51-7].» 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.
Packaging and storage—
Preserve in well-closed containers, and protect from moisture. No storage requirements specified.
Identification—
B:
Thin-Layer Chromatographic Identification Test 
201
—
201—
Test solution:
50 mg per mL, in methylene chloride.
Standard solution:
50 mg per mL, in methylene chloride.
Application volume:
10 µL, as streaks.
Developing solvent system:
a mixture of ether and hexane (70:30).
Spray reagent—
Prepare a 0.1 mg per mL solution of rhodamine 6G in alcohol.
Procedure—
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: the RF values of the principal spots obtained from the Test solution correspond to those obtained from the Standard solution.
C:
It meets the requirements of the test for Fatty acid composition.
Acid value 401:
not more than 0.2.
401:
not more than 0.2.
Hydroxyl value 401:
not more than 10.
401:
not more than 10.
Iodine value 401:
not more than 1.0.
401:
not more than 1.0.
Peroxide value 401:
not more than 1.0.
401:
not more than 1.0.
Saponification value 401:
between 310 and 335.
401:
between 310 and 335.
Unsaponifiable matter 401:
not more than 0.5%, determined on 5.0 g.
401:
not more than 0.5%, determined on 5.0 g.
Fatty acid composition 401—
Propylene Glycol Dicaprylate/Dicaprate exhibits the composition profile of fatty acids shown in the following table, as determined in the section Fatty Acid Composition under Fats and Fixed Oils 401.
401—
Propylene Glycol Dicaprylate/Dicaprate exhibits the composition profile of fatty acids shown in the following table, as determined in the section Fatty Acid Composition under Fats and Fixed Oils 401.
| 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 |
Water, Method Ia 921:
not more than 0.1%, using a mixture of methanol and methylene chloride (1:1) in place of methanol in the titration vessel.
921:
not more than 0.1%, using a mixture of methanol and methylene chloride (1:1) in place of methanol in the titration vessel.
Total ash 561:
not more than 0.1%.
561:
not more than 0.1%.
Alkaline impurities—
Dissolve 2.0 g of Propylene Glycol Dicaprylate/Dicaprate in a mixture of 1.5 mL of alcohol and 3.0 mL of ether. Add 0.05 mL of bromophenol blue TS. Not more than 0.15 mL of 0.01 N hydrochloric acid is required in order to change the color of the indicator to yellow.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
| Monograph | Hong Wang, Ph.D.
Scientist 1-301-816-8351 |
(EM205) Excipient Monographs 2 |
| Reference Standards | Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org |
USP32–NF27 Page 1325
Pharmacopeial Forum: Volume No. 33(5) Page 974