All categories



Menthol

This product is a colorless needle or prismatic crystal or white crystalline powder; it has a special aroma of mint; the ethanol solution shows a neutral reaction.

Product Details

Chinese common name: Menthol

English common name: l-Menthol (CP)

Racementhol (BP)

Mentholun racemicum (PhEur)

dl-Menthol (JP)

Menthol (USP)

Chinese Pinyin: Bohenao

Chemical name: L-1-methyl-4-isopropylcyclohexanol-3

Chemical Abstracts (CAS) Number: 1490-04-6 or 89-78-1

Unique ingredient identification (UNII): B1R15MTK7

1.1 Structure and composition

Molecular formula: C10H20O

Molecular weight: 156.27

Structural formula:

薄荷脑

1.2 Physical and chemical properties and basic characteristics

This product is a colorless needle or prismatic crystal or white crystalline powder; it has a special aroma of mint; the ethanol solution shows a neutral reaction.

Solubility: This product is easily soluble in ethanol, chloroform or ether, and very slightly soluble in water.

Specific rotation: -49°～-50°

Melting point: 42～44℃

Boiling point: 212℃

Flash point: 93°C

Refractive index: 1.4615【1】

Solubility: insoluble in ethanol, 95% ethanol, ether and water; slightly soluble in hot benzene and 95% ethanol.

Menthol is widely used in inhalants, oral suspensions, oral syrups, topical preparations, and tablets.

Menthol is widely used in medicines, candies and cosmetics as a corrective or flavoring agent. In addition to its unique mint fragrance, naturally occurring L-menthol also has a cooling function and is used in many topical preparations. Mannitol has a similar effect to this product due to its endothermic effect when dissolved; unlike mannitol, L-menthol can directly interact with the cooling receptors in the body. D-menthol has no cooling effect. And racemic menthol has about half the effect of L-menthol. When it is used to prepare flavor tablets, usually menthol is dissolved in 95% ethanol, and then sprayed on the tablet granules instead of being used as a solid excipient. Menthol has been studied as a penetration enhancer, it can also be used in perfumes and tobacco products, and as a therapeutic agent.

1.3 Literature information of addition amount:

Common dosage of preparation:

Inhaler 0.02-0.05% Oral suspension 0.003%

Tablet 0.2-0.4% Oral syrup 0.005-0.015%

Topical preparations 0.05-10.0%

Common amount of cosmetics:

Toothpaste 0.4% Mouthwash 0.1-2.0%

Oral spray 0.3%

Maximum usage:

L-Menthol

Inhaler 0.1% Oral chewing gel 3.84mg

Racemic menthol

Oral capsules 0.87mg Oral chewing gel 10.0mg

Oral liquid 0.07% Oral suspension 0.04% [2]

1.4 Quality standards

The quality standard of menthol is based on the four parts of the 2020 edition of the Chinese Pharmacopoeia

Menthol
Bohenao
l-Menthol

C₁₀H₂₀O 156.27 [1490-04-6]或[89-78-1]

The structure of this product is l-1-methyl-4-isopropylcyclohexanol-3, which is prepared from fresh stems and leaves of Mentha haplocalyx Briq., a plant of the family Lamiaceae, through steam distillation, freezing and recrystallization. The content of C10H20O should be 95.0%～105.0%.

【Properties】

This product is colorless needle-like or prismatic crystals or white crystalline powder; it has a special aroma of mint, tastes pungent at first, and cool afterwards; ethanol solution shows neutral reaction.

【Melting point】

The melting point of this product is 42～44° (General Rule 0612).

【Specific rotation】

Take this product, accurately weigh it, add ethanol to dissolve it and dilute it quantitatively to make a solution containing about 0.1g per 1ml, measured according to law (General Rule 0621), the specific rotation should be -49 to 50°.

【Identification】

(1) Take 1g of this product, add 20ml of sulfuric acid to dissolve it, and it will appear orange-red. After 24 hours, a colorless oil layer without menthol aroma will be precipitated (the difference from thymol).

(2) Take 50mg of this product, add 1ml of glacial acetic acid to dissolve, add 6 drops of sulfuric acid and 1 drop of nitric acid in a cold mixture, which is only light yellow (different from thymol).

【an examination】

Take an appropriate amount of this product, accurately weigh it, add an absolute ethanol solution and dilute quantitatively to make a solution containing about 50mg per 1ml, as the test solution; accurately measure an appropriate amount of menthol reference substance, add anhydrous ethanol to dissolve and quantitatively dilute A solution containing 0.5 mg of menthol per 1 ml was prepared as a reference solution. According to the chromatographic conditions under the content determination item, the column temperature is 110℃, and 1ul of the reference solution is injected into the gas chromatograph, and the detection sensitivity is adjusted so that the peak height of the main component chromatographic peak is 20% to 30% of the full scale; Measure 1ul each of the test solution and the reference solution, respectively inject into the gas chromatograph, and record the chromatogram until the retention time of the main component peak is twice. If there are impurity peaks in the test product chromatogram, the sum of the impurity peak areas shall not be greater than the main peak area of the reference solution (1.0%).

Non-volatile matter

Take 2.0g of this product, place it in an evaporating dish that has been dried to a constant weight, heat it on a water bath to slowly evaporate, and then dry it to a constant weight at 105°C, leaving no more than 1 mg of residue.

Heavy metals and harmful elements

According to the determination of lead, cadmium, arsenic, mercury, and copper (General Rule 2321), the content of lead shall not exceed 5 parts per million, cadmium shall not exceed 3 parts per million, arsenic shall not exceed 2 parts per million, and mercury shall not exceed 1,000 Two parts per million, copper must not exceed twenty parts per million.

Chromatographic conditions and system suitability test

The capillary column with cross-linked polyethylene glycol (or similar polarity) as the stationary phase is the chromatographic column; the column temperature is 120°C; the inlet temperature is 250°C; the detector temperature is 250°C; split ratio 10: 1. The number of theoretical plates should not be less than 10,000 based on the menthol peak.

Determination method Take 10mg of this product, accurately weigh it, put it in a 10ml measuring flask, add absolute ethanol to dissolve and dilute to the mark, shake well, accurately measure 1ul into the gas chromatograph, record the chromatogram; take another menthol reference substance, Determined in the same way. The peak area is calculated according to the external standard method, which is obtained.

【category】

Medicinal excipients, flavors and fragrances, etc.

【Storage】

Seal and store in a cool place.

Back to List

Consult online customer service

Service Hotline

+19956736262

Mailbox：
ahbzysy@163.com