astringent

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astringent

 [ah-strin´jent]
1. causing contraction or arresting discharges.
2. an agent that causes contraction or arrests discharges, usually locally after topical application. Astringents act as protein precipitants and arrest discharge by causing shrinkage of tissue. Skin preparations such as shaving lotions often contain astringents such as aluminum acetate that help to reduce oiliness and excessive perspiration. Witch hazel is a common household astringent used to reduce swelling. Styptic pencils, used to stop bleeding from small cuts, contain astringents. Zinc oxide and calamine are astringents used in lotions, powders, and ointments to relieve itching and chafing in various forms of dermatitis. Some astringents, such as tannic acid, have been used in treating diarrhea; others, such as boric acid and sodium borate, help relieve the symptoms of inflammation of the mucous membranes of the throat or conjunctiva of the eye. Astringents have some bacteriostatic properties, though they are not generally used as antiseptics.

as·trin·gent

(as-trin'jent),
1. Causing contraction or shrinkage of the tissues, arrest of secretion, or control of bleeding.
2. An agent having these effects.
[L. astringens]

astringent

/astrin·gent/ (ah-strin´jent)
1. causing contraction, usually locally after topical application.
2. an agent that so acts.

astringent

(ə-strĭn′jənt)
adj.
Medicine Tending to draw together or constrict tissues; styptic.
n.
A substance or preparation, such as alum, that draws together or constricts body tissues and is effective in stopping the flow of blood or other secretions.

as·trin′gen·cy n.
as·trin′gent·ly adv.

astringent

[əstrin′jənt]
Etymology: Gk, astringere, to tighten
1 a substance that causes contraction of tissues on application, usually used locally.
2 having the quality of an astringent. astringency, n.

astringent

adjective Causing local contraction after topical application.
 
Herbal medicine
noun Any herb that hardens and contracts tissues due to its high tannin content, preventing bacterial penetration and inhibiting discharges, diarrhoea and haemorrhage.

Pharmacology
A topical agent (e.g., aluminum-based compounds) that can be variably used: as topical haemostatics, to precipitate proteins, reduce mucosal inflammation, toughen skin, promote healing, as antiseptics, and to act as antiperspirants.

astringent

adjective Causing local contraction after topical application noun Pharmacology A topical agent–eg, aluminum-based compounds, used to precipitate proteins, as topical hemostatics, to ↓ mucosal inflammation, toughen skin, promote healing, as antiseptics, and as an antiperspirant

as·trin·gent

(ă-strin'jĕnt)
1. Causing contraction of the tissues, arrest of secretion, or control of bleeding.
2. An agent having these effects.
[L. astringens]

astringent

1. A drug that shrinks cells and tightens surfaces by denaturing cell protein.
2. Having the property of tightening surfaces.

astringent

agent used to control hyperhidrosis, e.g. topical application of 3% salicylic acid in IMS or 3% formalin in water; two or three crystals of potassium permanganate dissolved in 5 litres of warm water as a footbath, or Anhydrol Forte (Table 1)
Table 1: Topical agents with astringent/anhidrotic action
AgentFormulation
AlcoholIMS; 70% isopropyl alcohol; spirituous lotions, e.g. 3% salicylic acid in IMS; surgical spirit; evaporates to cool skin and reduce maceration
Formalin10% solution causes a toughening effect on epidermis (may cause hypersensitivity)
AgNO320-25% solution (higher strengths can be used as NaCl in sweat mitigates the action of AgNO3)
Tannic acidAs dusting powder, or as borotannic complex giving an antifungal action
HamamelisWitch hazel: cooling effect
CalamineLotion or cream with a mild astringent and absorbent action; it will take up 1.5 times its own weight of water
Salicylic acid 3%Astringent and antiseptic as a lotion or dusting powder
Burow's solutionAluminium acetate ∼5% solution; diluted 1:3 in water to reduce sweat flow
TalcAntipruritic and absorbent; used as a base for dusting powders and to lubricate the skin
Dusting powdersAstringent medicament (e.g. tannic acid, salicylic acid), or antifungal medicament (e.g. boric acid, undecenoic acid) and lubricating applications in a talc, kaolin and/or zinc oxide base
OthersAgents that coincidentally show astringent/anhidrotic action include potassium permanganate, sodium polymetaphosphate, ferric chloride and compound tincture of benzoin

Note: Astringents act variously to cause protein precipitation (and thereby reduce epidermal maceration), cooling of tissues, constriction of sweat ducts and skin lubrication); anhidrotics act variously as cooling agents, astringents, and to alter epidermal reaction to retained sweat (e.g. reduce friction at the skin surface).

Both are used to control hyperhidrosis and bromidrosis by preventing the accumulation of sweat, increasing the skin's reaction to the action of sweat, and to compensate for any loss of resistance to infection at the skin surface.

IMS, industrial methylated spirit.

astringent,

n a substance that contracts or tightens tissue, thereby alleviating conditions such as diarrhea, hemorrhages, and secretions.

astringent 

A chemical substance that causes contraction of soft organic tissues by precipitating proteins from their surfaces. Astringents are incorporated into some artificial tears. Examples: acetylcysteine, witch hazel, zinc sulfate. See artificial tears.

as·trin·gent

(ă-strin'jĕnt)
1. Causing contraction or shrinkage of the tissues, arrest of secretion, or control of bleeding.
2. An agent having these effects.
[L. astringens]

astringent (əstrin´jənt),

n styptic; an agent that checks the secretions of mucous membranes and contracts and hardens tissues, limiting the secretions of glands.

astringent

1. causing contraction or arresting discharges.
2. an agent that causes contraction or arrests discharges. Astringents act as protein precipitants; they arrest discharge by causing shrinkage of tissue.
Some astringents, such as tannic acid, have been used in treating diarrhea; others, such as boric acid and sodium borate, help relieve the symptoms of inflammation of the mucous membranes of the throat or conjunctiva of the eye. Skin lotions often contain astringents such as aluminum acetate that help to reduce oiliness and excessive perspiration. Witch hazel is a common household astringent used to reduce swelling. Styptic pencils, used to stop bleeding from small cuts, contain astringents. Zinc oxide and calamine are astringents used in lotions, powders and ointments to relieve itching and chafing in various forms of dermatitis. Astringents have some bacteriostatic properties, though they are not generally used as antiseptics.