Page 49 - Pharmacognosy-II (06-PG 303)

Interactions:

❑ The manufacturers of some enteric-coated peppermint oil preparations advise that indigestion
remedies (antacids) should not be taken at the same time as peppermint oil.

❑ This is presumably because a marked rise in pH caused by antacids might cause premature dissolution
of the enteric coating and release of the peppermint oil in the stomach, which increases the risk of
heartburn with the preparation. Separation of administration by a couple of hours usually avoids this
type of interaction with antacids.

❑ Some monographs extend this advice to H2-receptor antagonists and proton pump inhibitors and
suggest that these drugs should be avoided.

Pharmacological considerations:

✓ Peppermint leaf essential oil has been shown to slow intestinal transit, which may slow
the absorption rate or increase the total absorption of co-administered drugs.

✓ Peppermint leaf essential oil has been shown to relax the smooth muscles of the gastrointestinal
tract, which may exacerbate gastro esophageal reflux or hiatal hernias.

Pregnancy, Lactation and children:

Teratogenic effects were not observed in mice, rats, hamsters and rabbits for menthol tested at maximum
oral doses of 190, 220, 400 and 430 mg/kg/day, respectively.
Peppermint is compatible with breastfeeding but caution should be used. While the leaf probably is
compatible with breastfeeding, use of the oil should be discouraged. Caution should be exercised because
there is the view that use of peppermint may dry up milk secretions.

Note: Peppermint oil should not be applied to the nose, face or chest of babies and small children to avoid
laryngeal or bronchial spasm

Authentication: (Test for Identity and Purity):

1. Macroscopically, Microscopically and Organoleptic.

2. Chemically: test for Flavones, condensed tannins, and Volatile oil.

3. Chromatography (TLC and GC).

4. Specific tests.

Dosage forms:

Dried leaves, Tincture, Infusionand enteric-coated capsules.

Storage: in tightly closed containers (not plastic); in a cool, dry place, protected from light.

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