LECTURE OUTLINE

• ASTRINGENTS – CHANDER MOHAN AND

ISHIKA

• OBTUNDANTS – JASLEEN

• MUMMIFYING AGENTS – KAVYA

• BLEACHING AGENTS – LAKITA AND LALITA

• MOUTH WASHES – LISHA AND MANISHA

ASTRINGENTS

• The word "astringent" derives from Latin

adstringere, meaning "to bind fast".

• Definition- Astringent is a drug that reacts

chemically with cellular proteins producing limited

coagulation which is accompanied with shrinkage of

body tissues.

CHARACTERISTICS

• Affect only the superficial layer. Reduce cellular

permeability.

• Make the surface mechanically stronger, decrease

exudation.

• Protect from external irritation.

• Possess local styptic and local antiseptic action.

• May interfere with the function of pain receptors. The

pain relieving action is mild.

TYPES OF ASTRINGENTS

1. Vegetable astringents – tannic acid, gallic acid

2. Metallic astringents –

• Aluminium salts – alum, aluminium chloride,

aluminium acetate

• Zinc salts – zinc chloride, zinc sulfate

• Ferric chloride

• Strontium chloride

• Silver nitrate and copper sulfate

3. Others – very cold water, alcohol

CLASSIFICATION

According to their mode of action :

1. Those that decrease the blood supply by narrowing the small blood vessels, e.g. epinephrine, cocaine.

2. Those that abstract water from the tissue, e.g. glycerol and alcohol.

3. Those that coagulate the superficial tissue layers into a crust, e.g. metallic astringents such as calamine or alum.

ACTIONS OF ASTRINGENTS

• The general condensation of tissue.

• Diminished caliber of the arteries, veins, capillaries,

absorbents, and ducts.

• Diminished secretion, exhalation and absorption.

• Constipation of the bowels; and increased firmness

along with contraction of the pulse.

• Constrict blood vessels to stop bleeding.

• Harden the epidermis creating a barrier against

infection.

• Increase in appetite and invigorate digestion.

• Antioxidant.

• Inhibit mutagenicity of carcinogens.

INDICATIONS

• To check morbid discharges – generally or locally

• To obviate morbid relaxation – generally or locally

• To check inflammation in its earliest stage – applied

directly at the site

• Swollen, inflamed and/or leaky tissues :

-diarrhea, dysentery

-IBS, IBD

-leukorrhea (thick whitish/yellowish vaginal

discharge)

-Catarrhal states -cough, bronchitis, sore throats

-Canker sores and other oral infections

-Varicose veins

• Minor bleeding:

-Menorrhagia (heavy flow)

-Hemorrhoids

-Small wounds and burns

THERAPEUTIC USES OF

ASTRINGENTS

• Used internally to check discharge of blood, serum

or mucous secretions (in sore throat, diarrhea,

hemorrhage or peptic ulcers).

• Externally applied astringents, which cause mild

coagulation of skin proteins, dry, harden, and protect

the skin.

• Cleaning the face and preventing acne breakouts.

• Stopping bleeding.

• Haemorrhoids.

• Relief from minor skin irritations like superficial

cuts, allergies, insect bites, or fungal infections such

as athlete’s foot - Aluminium acetate and calamine

lotion.

• Other uses of astringents - in bleeding piles and as

antiperspirant/deodorant.

ASTRINGENTS USED IN DENTISTRY

Tannic acid and tannins

vegetable astringent.

source – nutgalls (tannic acid), tea, catechu, betelnut

(tannins).

actions :

-strengthen gums and check bleeding.

-tannins bind salivary proteins, precipitate them,

causing dry sensation.

uses :

-their preparations are used as astringent mouth wash, astringent dentrifices, local haemostatics, mummifying agent and obtundant.

efficacy is dubious.

Zinc chloride caustic astringent.

actions :

-Zinc reduces the permeability of cell membrane, alters the capillary epithelium, inhibits transcapillarymovement of plasma proteins and reduces local edema, inflammation, exudation and mucus secretion.

indications :

-ulcerative gingivitis, pyorrhoeal pockets and apthous

ulcers.

uses :

-included in several mouthwashes and dental gels.

Zinc sulfate

topical astringent for mucous membranes.

indications :

-mastoiditis, stomatitis and chronic alveolar abscess.

uses :

-included in mouthwashes and lotions.

Copper sulfate

Used as an astringent in indolent ulcer of gums.

Also used as a fungicide.

Disadvantage – stain the teeth.

Alum

Has astringent, antiseptic and haemostatic properties.

indications :

-to harden the gums or for inflamed/ulcerated gums.

Example- styptic pencils used to prevent bleeding from shaving cuts.

ALUM CRYSTAL USED AS ASTRINGENT

Aluminium chloride, ferric chloride,

strontium chloride

Included in many mouthwashes and gels.

Provide symptomatic relief, heal lesions, reduce

dentinal sensitivity and bleeding of gums.

Oak’s bark

actions : tighten tissues and strengthen blood vessels.

indications : weak and bleeding gums, damaged

gums.

ADVERSE EFFECTS

• Hydrolysable tannins are not recommended for long-

term use.

• Prolonged use can reduce absorption of nutrients, and

cause or worsen constipation.

• Form complex with metal ions and reduce

absorption.

• Irritation of mucous membranes.

• Carcinogenic when injected subcutaneously.