SKIN STRUCTURE

CONTENTS
PROTECTIVE

TOPICAL AGENTS ANTIMICROBIAL

ASTRIGENTS

Definition: Topical means pertaining to a particular
locality or place or simply it means “local”. Substances
which are applied directly on the skin or mucous
membrane or any other surface.

Protective and adsorbents:
drugs which adsorb intestinal toxins, bacteria etc,and
give a protective coating to the inflamed mucus memb.

TALC
Talcum, French Chalk, Purified talc

3MgO, 4SiO2, H2O Storage:
Test for Purity Talc is an inert substance not affected by
 Acidity or alkalinity acids or bases or other chemicals. So
 Water-Soluble substances store in a well closed container.
 Acid-Soluble substances
 Iron Medicinal and pharmaceutical Uses:
 Carbonates Pharmaceutical aid (dusting powder).
 Loss on drying Used as a filtering and distributing
 Organic compounds medium in the preparation of aromatic
 Chloride waters etc.

Main ingredient in talcum powders and
dusting powders

Zinc oxide/ZnO

Preparation
 Zinc oxide is prepared on a large

scale by burning zinc metal in a
current of air.

2 Zn + O2 = 2 ZnO

Storage:
Since it absorbs CO2 from the air, store it in a
well closed container.

Medicinal Use:
 Astringent and topical protective. ZnO is a

mild antiseptic and astringent. In the form
of ZnO ointment or dusting powder, it is
used in the treatment of eczema, Zinc Oxide Paste
ringworm, pruritus and psoriasis. Zinc Oxide: 250 gm

 It is also widely used in the mfg of Starch: 250 gm
plasters. White Soft Paraffin: 500 gm

 ZnO

Zinc stearate/(C17H35COO)2Zn

Mixture of Zn salts obtained
from commercial stearic acid which itself
is prepared from the hydrolysis of fats. It
consists mainly of variable proportions
of Zinc stearate and Zinc palmitate.

Medicinal and Pharmaceutical Uses:
Dusting powder. Since zinc
stearate is a mild antiseptic and
astringent, it is used in the form of
dusting powder or ointment in
several skin conditions. Sometimes it is
used as solid diluents.

CALAMINE

 Calamine BP: Basic ZnCO3 suitably colored with
ferric oxide.

 Calamine IP: ZnO colored with Ferric oxide. It is
an amorphous, reddish brown powder and the
color depends on the variety and amount of
ferric oxide present and the method by which it
is incorporated. It is practically insoluble in
water and completely soluble in mineral acids.

 Since there is a possibility of adulteration with
dyes, there are tests for water soluble dyes and
alcohol soluble dyes.

Medicinal and Pharmaceutical Uses:
Topical protective. Widely used in lotions, ointments and dusting
powders as soothing agent. It is used in sunburns, eczema and urticaria and
some other skin conditions.

Antimicrobial Agents and
Astringents

 These are the chemicals & their preparations used in reducing or

preventing infection due to microorganisms.

 Antiseptic: Inhibit the growth of MO (used for living object)

 Disinfectant: Destroy the Pathogenic MO (used for non living

object)

 Germicides: Kill Bacteria, Fungi, Viruses, Spores

 Bacteriostatic: Primarily inhibit the Bacteria – Only arrest their

growth not kill them.

 Sanitizers: For maintaining the health for sanitization purpose

Uses of antimicrobial agents

1. 1% solution used for using into the eyes of newborn babies, as

prophylactic measure against opthalmia neonaturum.

2. Effective against gonoccocal organisms.

3. 0.5% aqs soln in the form of wet dressing applied to third degree

burn.

Mechanism Of Action

1: Oxidation

2: Halogenation

3: Protein Precipitation

CLASSIFICATION OF DISINFECTANTS AND ANTISEPTICS

1. Halogens (Chlorinated Lime, Chloramine B, Chlorhexidine, Iodovidone)

2. Oxidizing agents (Hydrogen Peroxide, Potassium Permanganate)

3. Acids (Boric Acid)

4. Phenol derivatives (Phenol, Cresol,)

5. Aldehydes and alcohols (Formaldehyde, Ethanol, Isopropanol)

6. Metallic salts (Silver Nitrate, Zinc Sulfate, and Copper Sulfate)

7. Dyes or tints (Brilliant green, Methylene Blue)

8. Detergents (Decamethoxinum, Soaps)

Oxidative Anti-microbial
Agents

Hydrogen peroxide, H2O2

Laboratory method:
BaO2.8H2O + H2SO4 → BaSO4 ↓+ H2O2 + 8H2O

Industrial method:
2H2SO4 → H2S2O8 (aq.) + H2
H2S2O8 + 2H2O → 2H2SO4 + H2O2

Uses of H2O2
(i) Antiseptic and germicide for washing
wounds, teeth and ears, under the name of
perhydrol.
(ii) In the mfg of sodium perborate, sodium
percarbonate. These are used in high quality
detergents.
(iii) As an antichlor.

Zinc peroxide, ZnO2

 It is odorless white or yellowish solid.
 It is produced by adding ZnO or zinc hydroxide to a solution of H2O2.
 It can also be synthesized through the reaction of zinc chloride and

hydrogen peroxide.
 It is stable, insoluble in water and dissolves in acid forming H2O2 . It

decomposes at 150 OC to release O2

 Storage: Oxidiser, store in cool, away from light
 Away from incompatible materials (organic and reducing subs)

 Use: Anti-microbial agent in topical preparation, additive for aseptic

products
 It was historically used as a surgical antiseptic.

Potassium Permanganate,
KmnO4

Salt consisting of K+ and MnO4− ions. Formerly known as
permanganate of potash or Condy’s crystals, it is a strong oxidizing
agent.

Test for Purity:
Cl and SO4

Water-insoluble matter
Color of the solution

Storage:
should be kept separated from oxidizable substances. Store in
wellclosed
containers.

Uses:
As an oxidant, antiseptic
Permanganate washes were once used to treat
gonorrhea and are still used to treat candidiasis.
Antidote for strychnine

Iodine, I2

A dark violet (Greek, ioeides, violet) non-metallic
halogen element belonging to Group VIIb of the
periodic table.
Preparation:
Prepared by heating KI or NaI with dil. H2SO4 and
manganese dioxide.
2KI + MnO2 + 3H2SO4 → I2 + 2KHSO4 + MnSO4
+2H2O

Storage:
It is volatile in nature. Iodine topical solution should
be
stored in light-resistant containers at a
temperature not exceeding 35°C and iodine
tincture should be stored in air-tight containers.
Uses:
solution in alcohol, called “tincture of iodine” is
used as
antiseptic

Povidone-iodine (PVP-I) is a stable chemical complex of
polyvinylpyrrolidone (povidone, PVP) and elemental iodine. It contains
from 9.0% to 12.0% available iodine, calculated on a dry basis.

Astringents

 Are protein precipitant with limited penetration power
 It coagulates the protein on the surface of the cell and brings out

hardening effect.
 It constricts the tissue: Small Blood vessels
 These are mild Antimicrobial Agents

USES:
 Styptic to arrest minor bleeding by coagulation of blood
 Anti-perspirant to reduce perspiration by constricting pores of skin
 Anti-inflammatory action
 At high concentration to remove unwanted tissue growth
 Internally they can used in diarrhea
 As cosmetic as skin tone and bring out the hardening effect
 In dental products it can promotes hardening of the gums
 It reduces the cell permeability

Astringents

Aluminum Compound
 Alum:
 Potash Alum:[KAl(SO4)2, 12H2O]
 Ammonia Alum:[NH4Al(SO4)2,12H2O]
 Formula: AlK(SO4)2, 12H2O

 Synonyms:
 Aluminium Potassium Sulphate, Potash Alum, Potassium Alum

 Uses:
 Large dose gives irritation and gives Gum Necrosis, GI
 Haemorrhage, adjuvant with vaccine (DTP)
 Alum precipitate proteins
 To apply on sores
 Used as mordant in dyeing industry. (a substance, that
 combines with a dye or stain and thereby fixes it in a material.)

Zinc Sulfate ZnSO4

 Three forms are official – Heptahydrate, Hexahydrate,
monohydrate
 Formula: ZnSO4.7H2O

 Preparation:
 Zns + 2O2 → ZnSO4
 Zn + H2SO4 → ZnSO4 + H2

 Properties:
 Colorless, transparent crystals, odorless
 Very soluble in water; practically insoluble in ethanol

 Uses:
 In variety of Skin condition (keratosis), viral infection of genitals,

pityriasis (skin rash).
 Water soluble Zn is used as supplements for Zn deficiency.

Protein precipitant antimicrobial agents

Silver Nitrate, AgNO3

 Inorganic compound with chemical formula AgNO3.
 Test for Purity:
Clarity and color of the solution
Acidity and alkalinity
Foreign salts
 Al, Bi, Cu and Pb
 Storage:
Affected by light, store in tightly closed light resistant
containers.
 Uses:
 Antiseptic properties. Until the development of

antibiotics,
 Dilute solutions of AgNO3 used to be dropped into

newborn babies’ eyes at birth to prevent contraction of
gonorrhea from the mother.

Boric acid, H3BO3, B(OH)3

aka hydrogen borate, boracic acid, orthoboric acid & acidum boricum.
Colorless crystals or a white powder that dissolves in water

Preparation of boric acid:
Reacting borax (sodium tetraborate decahydrate)
with a mineral acid:
Na2B4O7・10H2O + 2HCl → 4 B(OH)3 [or H3BO3] + 2NaCl + 5H2O

Uses:
 Antiseptic for minor burns or cuts and is

sometimes used in dressings.
 Very dilute solution as an eye wash.
 Dilute boric acid can be used as a vaginal

douche to treat bacterial vaginosis due to
excessive alkalinity.

 For acne treatment. For prevention of
athlete’s foot, by inserting powder in the
socks or stockings.