Formula

C10H20O.

Derivation

Menthol is the stearoptene of peppermint oil, and is obtained from this oil either by long keeping or by being cooled at a low temperature. Chemically, menthol occupies the position of an alcohol, having in its composition four atoms more of hydrogen than the ordinary camphor, and containing the radical menthyl. It is in the form of a crystalline solid, composed of small white crystals of a peppermint odor and resembling sulphate of magnesia. It is imported as Japanese camphor, its chief source being the Japanese and Chinese peppermint oils. In a liquid state it has a specific gravity less than that of water. It is rendered liquid and volatile at a temperature one or two degrees below that of the body. It is sparingly soluble in cold water, liquefying slowly in water at 820 F., quickly at 120° F., but remains mostly as a separate body. It is freely soluble in alcohol, ether, glycerine and in the fixed and volatile oils.

Medical Properties And Action

Menthol is anodyne, antispasmodic, and antiseptic. In doses of gr. 1/10 to 1/6 it steadies the contractions of an excited heart, and causes tranquillity, and at the same time slight cerebral drowsiness.

Half a grain may cause vomiting from gastric irritation, hence care should be observed in its administration, either internally or externally about the mouth. Its internal use is not advocated, unless well diluted, but its principal use is as an external application.

Therapeutic Uses

Menthol is said to prove as effectual as aconite, veratria and atropine for such diseases as neuralgia, bra-chalgia and gout; more so it is claimed by some. It is also used in chronic rheumatism and in headache. It is also applied in putrefactive wounds, as an antiseptic.

Dental Uses - In dental practice, menthol has given satisfaction as an external remedy in facial neuralgia, odontalgia, as an obtunder of sensitive dentine, and as a local anaesthetic. For relieving the pain of sensitive dentine, a small portion of the crystals is applied to the sensitive surface, and in a few minutes the local anaesthetic effect is produced. As an antiseptic it has been employed in the treatment of decomposing pulps of teeth, necrosed teeth, etc. When applied to mucous surfaces for its anaesthetic effect, a twenty to thirty per cent. solution is used, but it is more evanescent than cocaine. Menthol also forms an ingredient of a devitalizing mixture.

The oil of the ordinary peppermint is considered to be a germicide and antiseptic of considerable power and rapidity. It is readily diffusible, does not evaporate quickly, and is non-poisonous. It is useful in root-canals and fistulous tracts after removal of pulps, and for hypersensitive dentine.

Dental Formulae

For Facial Neuralgia and Odontalgia.

Mentholi......gr.j

Spts. vini rectificati .

Olei caryophylh . . . Signa. - For facial neuralgia, painted on the affected part. For odontalgia, applied on cotton to carious cavity.

Dental Formulae 1204Dental Formulae 1205

For Neuralgia and Odontalgia.

Mentholi......gr.v

Olei caryophylli (or oil of cajeput) .... Signa. - To be painted on affected part, or, for odontalgia, applied on cotton.

Dental Formulae 1206Dental Formulae 1207

Local Anaesthetic.

For Abscesses, Boils, Felons, etc.

Chloroformi.....

Ether sulphurici . . .

Mentholi.......

Signa

Use with spray apparatus.

Signa 1208Signa 1209

For Odontalgia.

Mentholi .... gr.xv Cocaine hydrochlor. gr.xv

Pul. opii.....

Mucilag. acaciae, Pulv. altheae . .. . aa q. s. M. Signa. - Introduce on a pledget of cotton.

Signa 1210Signa 1211

For Odontalgia.

Mentholi .... 5 parts Chloroformi ... 8 parts. M. Signa. - Apply on cotton.

Signa 1212

Local Anaesthetic.

Dr. A. W. Harlan.

Mentholi ... 2 parts Ether .... 15 parts Chloroformi . 100 parts. M. Signa. - For injection, or applied on cotton about tooth.

Signa 1213

For Odontalgia.

Dr. Schaeffer.

Phenol crystals..............I part

Mentholi................3 parts.

Melt over a moderate heat. Signa. - Apply to inflamed pulp.

Signa 1214