Glyceryl Palmitostearate

Basic Information

Name: Glyceryl Palmitostearate

CAS No: Octadecanoic acid, 2,3-dihydroxypropyl ester mixed with 3-hydroxy-2-[(1-oxohexadecyl)-oxy] propyl octadecanoate [8067-32-1]

Functional Categories

Biodegradable material Coating agent Gelling agent Sustained-release agent Tablet and capsule diluent Tablet and capsule lubricant Taste-masking agent Release-modifying agent

1. Nonproprietary Names

None adopted.

2. Synonyms

Glycerin palmitostearate; glycerol palmitostearate; 2-[(1-oxohexadecyl)-oxy]-1,3-propanediyl dioctadecanoate and 1,2,3-propane triol; Precirol ATO 5

3. Chemical Name & CAS Registry

Octadecanoic acid, 2,3-dihydroxypropyl ester mixed with 3-hydroxy-2-[(1-oxohexadecyl)-oxy] propyl octadecanoate [8067-32-1]

4. Empirical Formula & Molecular Weight

Glyceryl palmitostearate is a mixture of mono-, di-, and triglycerides of C16 and C18 fatty acids.

6. Applications

Glyceryl palmitostearate is used in oral solid-dosage pharmaceutical formulations as a lubricant.(1,2) Disintegration times increase(3) and tablet strength decreases(4) with increase in mixing time. It is used as a lipophilic matrix for sustained-release tablet and capsule formulations.(5,6) Tablet formulations may be prepared by either granulation or a hot-melt technique,(7,8) the former producing tablets that have the faster release profile. Release rate decreases with increased glyceryl palmitostearate content.(5) Glyceryl palmitostearate is used to form microspheres, which may be used in capsules or compressed to form tablets,(9,10) pellets,(11) coated beads,(12) and biodegradable gels.(13) It is also used for taste-masking.(14) See Table I.

7. Description

Glyceryl palmitostearate occurs as a fine white powder with a faint odor

8. Pharmacopeial Specifications

9. Typical Properties

Acid value <6.0 Boiling point 2008C Color <3 (Gardner scale) Free glycerin content <1.0% Heavy metals <10 ppm Hydroxyl value 60–115 Iodine value <3 Melting point 52–558C 1-Monoglycerides content 8.0–17.0% NIR spectra see Figure 1. Peroxide value <3.0 Saponification value 175–195 Solubility Freely soluble in chloroform and dichloromethane; practically insoluble in ethanol (95%), mineral oil, and water. Sulfated ash <0.1% Unsaponifiable matter <1.0% Water content <1.0%

10. Stability & Storage

Glyceryl palmitostearate should not be stored at temperatures above 358C. For storage for periods over 1 month, glyceryl palmitostearate should be stored at a temperature of 5–158C in an airtight container, protected from light and moisture.

11. Incompatibilities

Glyceryl palmitostearate is incompatible with ketoprofen(15) and naproxen.(16)

12. Method of Manufacture

Glyceryl palmitostearate is manufactured, without a catalyst, by the direct esterification of palmitic and stearic acids with glycerol.

13. Safety

Glyceryl palmitostearate is used in oral pharmaceutical formulations and is generally regarded as an essentially nontoxic and nonirritant material. LD50 (rat, oral): >6 g/kg(14)

14. Handling Precautions

Observe normal handling precautions appropriate to the circumstances and quantity of material handled.

15. Regulatory Status

GRAS listed. Included in the FDA Inactive Ingredients Database (oral suspension, oral tablet). Included in nonparenteral preparations licensed in Europe. Included in the Canadian List of Acceptable Non-medicinal Ingredients.

16. Related Substances

Glyceryl behenate; glyceryl monostearate.

17. Comments

The EINECS number for glyceryl palmitostearate is 232-514-8. The PubChem Compound ID (CID) for glyceryl palmitostearate is 114690.