DL-Menthol Property

Melting point:

34-36 °C(lit.)

Boiling point:

216 °C(lit.)

Density 

0.89 g/mL at 25 °C(lit.)

vapor pressure 

0.8 mm Hg ( 20 °C)

FEMA 

2665 | MENTHOL RACEMIC

Flash point:

200 °F

storage temp. 

Sealed in dry,Room Temperature

solubility 

Very soluble in ethanol (95%), chloroform, ether, fatty oils and liquid paraffin; freely soluble in glacial acetic acid;soluble in acetone and benzene; very slightly soluble in glycerin; practically insoluble in water.

pka

15.30±0.60(Predicted)

form 

Solid

color 

Clear Colourless

Odor

at 10.00 % in dipropylene glycol. cooling mentholic minty

Odor Type

mentholic

JECFA Number

427

Dielectric constant

3.2（Ambient）

Stability:

Stable. Combustible. Incompatible with strong oxidizing agents.

InChIKey

NOOLISFMXDJSKH-UHFFFAOYSA-N

LogP

3.3-3.79 at 25℃

CAS DataBase Reference

1490-04-6(CAS DataBase Reference)

NIST Chemistry Reference

Menthol(1490-04-6)

EPA Substance Registry System

Menthol (1490-04-6)

Safety

Hazard Codes 

Xn,Xi

Risk Statements 

37/38-41-48/20/22-40-22

Safety Statements 

36/37/39-36-26

RIDADR 

UN 1888 6.1/PG 3

WGK Germany 

2

RTECS 

OT0525000

HS Code 

29061100

Hazardous Substances Data

1490-04-6(Hazardous Substances Data)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H315Causes skin irritation

H318Causes serious eye damage

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P271Use only outdoors or in a well-ventilated area.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

DL-Menthol Chemical Properties,Usage,Production

Chemical Properties

colourless crystals

Chemical Properties

Racemic menthol is a mixture of equal parts of the (1R,2S,5R)- and (1S,2R,5S)-isomers of menthol. It is a free-flowing or agglomerated crystalline powder, or colorless, prismatic, or acicular shiny crystals, or hexagonal or fused masses with a strong characteristic odor and taste. The crystalline form may change with time owing to sublimation within a closed vessel. The USP 32 specifies that menthol may be either naturally occurring l-menthol or syntheti-cally prepared racemic or dl-menthol. However, the JP XV and PhEur 6.0, along with other pharmacopeias, include two separate monographs for racemic and l-menthol.

Uses

menthol is a fragrance. It is also said to be anti-septic, cooling, refreshing, and a blood-circulation stimulant. Menthol gives the skin a “cool” feeling after use. It constitutes almost 50 percent of peppermint oil but can also be synthetically produced through the hydrogenation of thymol. It is non-toxic in low doses, but in high concentrations it can be irritating to the skin, especially the mucous membranes.

Uses

Labelled Menthol. Used for oral gel patch or film containing herb extracts or Chinese medicine, fruit extract, spearmint, and menthol for smoking cessation.

Uses

Menthol is used in confectionery, perfumery, cough drops, cigarettes, liqueurs, etc.; topical antipruritic; local anesthetic; gastric sedative.

Definition

A white crystalline terpenealcohol, C₁₀H₁₉OH; r.d. 0.89;m.p. 42°C; b.p. 103–104°C. It has aminty taste and is found in certainessential oils (e.g. peppermint) andused as a flavouring.

Production Methods

Menthol occurs widely in nature as l-menthol and is the principal component of peppermint and cornmint oils obtained from the Mentha piperita and Mentha arvensis species. Commercially, lmenthol is mainly produced by extraction from these volatile oils. It may also be prepared by partial or total synthetic methods.
Racemic menthol is prepared synthetically via a number of routes, e.g. by hydrogenation of thymol.

Definition

ChEBI: Any secondary alcohol that is one of the eight possible diastereoisomers of 5-methyl-2-(propan-2-yl)cyclohexan-1-ol.

brand name

Fisherman’s Friend Lozenges (Bristol-Myers Products); Therapeutic Mineral Ice (Bristol-Myers Products).

Pharmaceutical Applications

Menthol is widely used in pharmaceuticals, confectionery, and toiletry products as a flavoring agent or odor enhancer. In addition to its characteristic peppermint flavor, l-menthol, which occurs naturally, also exerts a cooling or refreshing sensation that is exploited in many topical preparations. Unlike mannitol, which exerts a similar effect due to a negative heat of solution, l-menthol interacts directly with the body’s coldness receptors. d-Menthol has no cooling effect, while racemic menthol exerts an effect approximately half that of l-menthol.
When used to flavor tablets, menthol is generally dissolved in ethanol (95%) and sprayed onto tablet granules and not used as a solid excipient.
Menthol has been investigated as a skin-penetration enhancer and is also used in perfumery, tobacco products, chewing gum and as a therapeutic agent. When applied to the skin, menthol dilates the blood vessels, causing a sensation of coldness followed by an analgesic effect. It relieves itching and is used in creams, lotions, and ointments. When administered orally in small doses menthol has a carminative action.

Safety

Almost all toxicological data for menthol relate to its use as a therapeutic agent rather than as an excipient. Inhalation or ingestion of large quantities can result in serious adverse reactions such as ataxia and CNS depression,hypersensitivity reactions, severe abdominal pain, nausea, vomiting, vertigo, drowsiness, and coma.Although menthol is essentially nonirritant there have been some reports of hypersensitivity following topical application. In a Polish study approximately 1% of individuals were determined as being sensitive to menthol.There have been reports of apnea and instant collapse in infants after the local application of menthol to their nostrils.
The WHO has set an acceptable daily intake of menthol at up to 0.4 mg/kg body-weight.
LD₅₀ (rat, IM): 10.0 g/kg
LD₅₀ (rat, oral): 3.18 g/kg

storage

A formulation containing menthol 1% w/w in aqueous cream has been reported to be stable for up to 18 months when stored at room temperature.
Menthol should be stored in a well-closed container at a temperature not exceeding 25°C, since it sublimes readily.

Incompatibilities

Incompatible with: butylchloral hydrate; camphor; chloral hydrate; chromium trioxide; b-naphthol; phenol; potassium permanganate; pyrogallol; resorcinol; and thymol.

Regulatory Status

Included in the FDA Inactive Ingredients Database (dental preparations, inhalations, oral aerosols, capsules, solutions, suspensions, syrups, and tablets; also topical preparations). Included in nonparenteral medicines licensed in the UK. Accepted for use in foods and confectionery as a flavoring agent of natural origin. Included in the Canadian List of Acceptable Non-medicinal Ingredients.