3. Excipients
■ Pharmaceutical excipients can be defined as
nonactive ingredients that are mixed with
therapeutically active compound(s) to form
medicines.
■ The ingredient which is not an active compound is
regarded as an excipient.
■ Excipients affect the behaviour and effectiveness of
the drug product more and more functionality and
significantly.
■ The variability of active compounds, excipients and
process are obvious components for the product
variability
4. Significance of Natural
Excipients
■ These polymers such as natural gums and mucilage
are biocompatible, cheap and easily available and
are preferred to semi synthetic and synthetic
excipients because of their lack of toxicity, low cost,
availability, soothing action and non irritant nature
5. Natural Colorants
■ Highly coloured substances found in plants and
animals.
■ A dye and pigment differ in respect that, dye is
actually absorbed by the material when applied to
fibres to give it a permanent colour which is resistant
to the action of light, water or soap.
■ A pigment on other hand is only applied to the
surface.
■ The coloured compounds are known as chromogen
and bear chromophore group and/or auxo chrome
capable of absorbing light in the near UV regions and
appears as coloured substance.
6. Natural Colorants
Source Compound Color Shade
Anthraquinones
Dactylopius coccus (Cochineal) Carminic acid Red
Rubia tinctorum (Madder) Alizarin Red
Coccus laccae (Lac) Laccaic acid Red
Kermes ilicis (Shiled louse) Kermisic acid Scarlet
Naphthoquinones
Lawsonia inermis (Henna)
Lawsonia alba
Lawsone Orange
Juglans regia (Walnut)
Juglans nigra
Juglone Brown
Lithospermum erythrorhizon
(Shikone)
Shikonin Violet
8. Henna
■ Source: dried leaves of Lawsonia inermis (L. alba)
■ Family: Lythraceae
■ GS: North Africa, India, Srilanka
■ Constituents: Phenolic glycosides, Coumarins,
Xanthene, Flavonoids, Fats, Resin and Henna tannin
■ Coloring matter: Lawesone, which can be extracted
from the leaves by NaHCO3.
■ Lawsone is 2,5-dihydroxy-1,4-naphthoquinone
■ used to dye protein fiber in an orange shade, in
conjuction with dihydroxyacetone as a sunscreen
agent
9. Turmeric
■ Source: dried rhizomes of Curcuma longa
■ Family: Zingiberaceae
■ GS: Subtropical regions
■ Contains a yellow natural pingment, which dissolves
in alcohol to form a deep yellow solution.
■ Alkali changes the colour to reddish orange
■ Constituents: 5% curcumins and its derivatives,
which are diaryl heptanoid compounds of dark
yellow color. Curcumin, desmethoxy curcumin and
bisdesmethoxy curcumin.
10. Turmeric
■ Use: principally as a constituents of curry powder.
■ It imparts dark yellow color to food preparations.
■ A tincture is used for preparation of turmeric paper
which is used as a test for boric acid and borates
■ Curcumin is used as a yellow coloring matter but the
color is fugitive in solution.
11. Natural sweeteners
■ Sweetening agents either evoke sweet taste or
enhance the perception of sweet taste. Natural
sweetening agents are preferred over synthetic
sweetening agents since they do not have any
adverse impact on health.
■ Two types of sweeteners are available: natural
sweeteners of plant origin and artificial or synthetic
sweeteners.
■ Non-saccharide natural sweetening agents are low
calorific, nontoxic and super sweet (100 to 10,000
times sweeter than sugar) in nature and can
overcome the problems of sucrose and synthetic
sweeteners.
12. Natura sweeteners
■ Natural sweeteners are useful sugar substitutes for
diabetic patients.
■ The active sweet principles stored in plants can be
grouped under: terpenoids, steroidal saponins,
dihydroisocoumarins, dihydrochalcones, proteins,
polyols, volatile oils, etc. in nature.
■ Nutritive sweeteners: sorbitol, mannitol, xylitol,
lactitol, mixture of glucosylsorbitol &
glucosylmannitol, fructose
■ Non-nutritive sweeteners: Aspartame, Saccharin,
cyclamate, acesulfane-k and alitame
■ Plant based natural sweeteners: Stevioside,
Glycyrrhizin, Neohesperidin, Thaumatin, Monellins,
Sucralose
14. Stevia
■ Source: extracted from a south American plant
“Stevia rebaudiana”
■ Family: Compositae
■ GS: Paraguay, Brazil, Japan, China, Taiwan, Thailand,
Malaysia
■ The dried leaves of the plants, the water extract of
the leaves and the purified ingredients of the extract
are used as sweetening agents.
■ Stevioside can be isolated from the leaves of Stevia
by extraction with water or water-ethyl alcohol
mixture and further purified by treatment with
calcium or MgOH or Mg(CO3)2.
15. Stevia
■ The ratio of rebaudioside A to stevioside can be
increased by extraction with methanol.
■ 2 compounds isolated and purified from Aqueous
extract are stevioside and rebaudioside A.
■ Both these compounds are diterpene glycoside.
■ Stevioside is 160-170 times sweeter than sucrose.
■ Its sweetness is tainted with a bitter and undesirable
after taste. But its wide use in Japan for over 20 years
did not produce any known deleterious side effects.
■ In USA the FDA allowed the use of Stevia as a diet
supplement but not as sweetener or an ingredient of
food.
16. Stevia
■ Stevioside and rebaudioside A give rise to its
principal steviol which has been reported to be
mutagenic.
■ Stevioside, the more important product, is used as
table top sweetener, in confectionaries, soft drinks
and fruit products.
■ The sweetness intensity of rebaudioside A is
approximately 1/3rd higher than that of stevioside
and its taste characteristics are also superior, but it is
unstable and gets decomposed to light.
17. Neohesperidin dihydrochalcone
■ Source: It’s a flavonoid compound present in bitter
orange Citrus aurantium variety amara
■ Family: Rutaceae
■ Neohesperidin dihydrochalcone is obtained by
hydration of neohesperidin under alkaline
conditions.
■ It is also produced from flavonoid naringin present in
peels of several other Citrus spp.
■ Though neohesperidin dihydrochalcone is prone to
hydrolytic cleavage of glycosidic bond, its stability is
acceptable under food processing and storage
conditions.
■ Its about 330 times sweeter than sucrose.
18. Neohesperidin dihydrochalcone
■ Neohesperidin dihydrochalcone is characterized by
pronounced methanol like after taste which limits its
use ad allows it to make only a partial contribution in
food and pharmaceutical industry.
■ It acts as synergistically with number of other
sweeteners e.g. acesulfame and aspartame can be
used in very small quantities in blends with these
sweeteners.
■ It is used in confectionery products, chewing gum, in
beverages and dairy products.
■ In addition to sweetness, neohesperidin
dihydrochalcone has flavour enhancing properties in
a variety of foods and other products.
19. Natural Binding agents
■ Binders are agents employed to impart cohesiveness
to the granules. This ensures the tablet remains
intact after compression.
■ Binders are added to tablet formulation to impart
plasticity and thus increase the interparticulate
bonding strength within the tablet.
■ To hold various powders together to form a tablet is
a binder, fillers usually do not have good binding
capacity, binder is either added in dry mix or mix in
granulating liquid, binder form matrix with fillers and
drug embedded in it, on drying solid binder forms
glue which holds the particles together, the wet
binder is the most important ingredient in the wet
granulation process, most binders are hydrophilic &
most times soluble in water.
20. Advantage: Natural binders
■ low toxicity, biodegradable, availability and low cost
■ can also modify the release of drug, thereby,
influencing the absorption and subsequent
bioavailability of the incorporated drug
■ Increase stability, precision and accuracy of dosage
form
■ improve the organoleptic properties of the drugs
where necessary in order to enhance patient
adherence
21. Disadvantage: Natural binders
■ Over time they occasionally lead to tablet hardening
and a decrease in dissolution performance.
■ When polymer binders are chosen, the addition of
strong disintegtants such as super disintegrants is
typically required but these are considerably
expensive and have a negative effect on product
stability as well as film coating appearance of the
finished products
■ E.g. Plant starch, pregelatinized starch, gelatin,
Plant Gums: acacia, tragacanth
22. Acacia
■ Source: dried gummy exudation from the stems and
branches of Acacia arabica, A. senegal etc,
■ Family: Leguminosae
■ English: Indian Gum, Hindi: Babul
■ Description: White or yellowish- white thin flakes,
spheroidal spheres (up to 32 mm in diameter),
powder, granules, or spray-dried powder. Odourless
and bland taste
■ Solubility: 1 in 20 of Glycerin, 1 in 20 of PEG, 1 in 2.7
of water, practically insoluble in alcohol
■ Constituents: (-) arabinose, (+-) galactose, (--
rhamnose), (+ - glyceronic acid)
23. Acacia
■ Chemical test:
■ Powder + Lead sub acetate gelatinises the
aqueous solution
■ Powder + ruthenium red no pink colour
■ Powder in Water + H2O2 + benzidine in alcohol
blue colour (oxidase enzyme)
■ Incompatibilities: with Ferric salts amidopyline,
apomorphine, borax, basic lead acetate, AlCl3,
cresol, ethanol, morphine, phenol, tannin, thymol,
gelatine, vanillin
■ Method of sterilization: Autoclaving
■ Uses: tablet binder (1-5%), suspending agent (5-
10%), emulsifying agent (10-20%), mucilage,
thickener
■ Storage: air tight container in a cool, dry place.
24. Gelatine
■ Syn: Gelfoam, Puragel, Gelatina
■ Source: A protein obtained by partial hydrolysis of
animal collagenous tissues like bone, skin, tendon and
ligaments.
■ Description: faintly yellow amber coloured solid with
characteristic odour. Its available in the form of flakes,
sheets, shreds, powder or granules.
■ Properties: Gelling strength:150-200
■ Solubility: practically insoluble in water, most of
organic solvents, fixed oil and volatile oils
■ Soluble in hot water, glycerol, acetic acid
■ In 5-10 times water, forms gel below 35-40 degree C
25. Gelatine
■ Constituents: Glycine (25-27%), Alanine, Glutamic acid,
Proline, Arginine, Aspartic acid and Hydroxy proline,
Isoleucine, Leucine, phenyl alanine, tryptophan
■ ChemicalTest:
■ Powder, when heated with soda lime, evolves ammonia
gas
■ Powder with picric and tannic acid, precipitation
■ Powder + HgNO3 white ppt, on heating turn to
red-brick red colour (Millon’s reagent)
■ Incompatibilities: Tannins and Formaldehyde
■ Method of sterilization: Dry heat Sterilization
26. Gelatine
■ Use: preparing suppositories, pastilles, pessaries,
pastes.
■ Absorbable gelatine sponge: Haemostatic
■ Emulsifying agent, vehicle for injection
■ Manufacture of hard and soft gelatine capsule
■ Tablet binder
■ Stabilizer, thickener,
■ 2% mascara preparation
■ Storage: tight container in dry place
27. Natural diluents
■ Diluents are often added to tablet formulations for
secondary reasons like to provide better tablet
properties such as:
i)To provide improved cohesion
ii)To allow direct compression manufacturing
iii)To enhance flow
iv)To adjust weight of tablet as per die capacity
■ should neither support microbiological growth in the
dosage form nor contribute to any microbiological
load
■ should neither adversely affect the dissolution of the
product nor interfere with the bioavailability of
active pharmaceutical ingredient
■ should preferably be colourless or nearly so.
28. Natural diluents
■ should not react with the drug substance and
moreover it should not have any effect on the
functions of other excipients
■ should not have any physiological or
pharmacological activity of its own
■ should have consistent physical and chemical
characteristics
■ should neither promote nor contribute to
segregation of the granulation or powder blend to
which they are added
■ should be able to be milled (size reduced) if
necessary in order to match the particle size
distribution of the active pharmaceutical ingredient
29. Lactose
■ Source: a natural disaccharide consisting of
galactose and glucose and obtained from milk of
most of mammals.
■ Syn: Milk sugar, Lactin
■ Description: white crystalline powder with odourless
and faintly sweet taste. It is stable in air but readily
absorbs odours.
■ Several varieties of lactose are available: anhydrous
alpha, alpha monohydrate and anhydrous beta
■ Hygroscopicity: absorbs insignificant amount of
moisture at 25 degree at relative humidity up to
about 90%
30. Lactose
■ Solubility: freely soluble in water while practically
insoluble in CHCl3, ethanol and ether
■ Constituents: O-beta-D-galactopransosyl-(1-4)-
alpha-D-glucopyranose
■ Chemical test:
■ 0.25 g lactose + 5 ml water + 5 ml of 10M NH3
heat in water bath at 80 degree for 10 minutes,
red colour develops
■ 5 ml hot saturated solution of lactose + 5 ml NaOH
warm yellow liquid, finally brownish red on
adding several drops of cupric sulphate, a red ppt of
Cu(OH)2.
31. Lactose
■ Incompatibilities: primary amine group
■ Method of sterilization: dried at 105 degree then
sterilized by dry heat.
■ Use: diluent in tablets, capsules, dry powder
inhalations
■ Used in combination with sucrose to prepare sugar
coating solutions (Appro. 1:3)
■ Direct compression grades of lactose combined with
MCC or starch and usually requires tablet lubricant
0.5% w/w magnesium stearate.
■ Storage: well closed container in a cool dry place
32. Mannitol
■ Source: saccharine exudation from the stem of
Fraxinus ornus, family: Oleaceae
■ A hydrolytic alcohol obtained by isolation from
Manna seeds.
■ It can be also be obtained chemically by reduction of
mannose.
■ Description: white, crystalline, odourless, non
hygroscopic and sweet powder. The crystals are
orthorhombic prisms. The melting point is 166-168
degree C. It is freely soluble in water and insoluble in
alcohol. Its specific gravity is 1.52 and optically
inactive or slightly levo rotatory.
33. Mannitol
■ Uses: Sweetening agent & 10-19% w/w as a diluent
■ Doesn’t get absorbed by GIT. It is not metabolized
and is eliminated by glomerular filtration.
■ Can be used as diagnostic aid
■ Method of sterilization: well closed well filled
container
34. Viscosity builders
■ These are substances, which added to mixture, to
increase its viscosity without substantially modifying
its other properties , such as taste.
■ They increase stability.
■ It is desirable to increase the viscosity of dosage
form to provide or to improve palatability or
pourability
35. Viscosity builders:
Advantages:
■ High viscosity inhibits the crystal growth.
■ High viscosity enhances the physical stability
■ High viscosity prevents the transformation of
metastable crystal to stable crystal
Disadvantages:
■ High viscosity hinders the re-dispersibility of the
sediments.
■ High viscosity retards the absorption of the drug.
■ High viscosity creates problems in handling of the
material during manufacturing.
36. Viscosity builders:
Ideal characteristics:
Should produce a structured vehicle
Should have high viscosity at negligible shear during
storage and low viscosity at high shearing rates
during pouring
Should exhibit yield stress
Should be compatible with other excipients
Should be nontoxic
Viscosity should not be altered by temperature or on
aging
37. Carrageenan
■ Syn: chondrus extract, Iris moss extract
■ Source: sulphated polysaccharide extract of the sea
weed called Carrageenan; or irish mosss, the red-
algae obtained from Chondrus crispus belonging to
family, Rhodophyllaceae
■ GS: North Atlantic coast of Europe, North America
■ France, Spain, Denmark, USA, major producers of
carrageenan in the world market
■ Description: water soluble colloid, dried for the free
flowing powder, stable at pH 9.0
■ Two forms of drugs are available, extracted with cold
water gives viscous solution in water
■ Extracted with hot water forms gel on cooling
38. Carrageenan
■ Constituents: depending upon the position of
sulphate and presence or absence of
anhydrogalactose, two types of carrageenan are
know, kappa and lambda.
■ Kappa carrageenan:
■ Ability to form thermos reversible gel, soluble in
polar solvents, in hot milk and hot conc. Sugar
solution above 60 degree C
■ Sodium salt of this form is soluble in cold water while
calcium and potassium salts are insoluble in cold
water
■ k-carrageenan contains D-galactose, 3,6 anhydrous-
D-galactose and ester sulphate group
39. Carrageenan
■ Kappa carrageenan is good gelling agent, while
lambda carrageenan is non gelling and is good
thickener.
■ Lambda carrageenan contains D-galactose and its
mono and bisulphate esters.
■ Carrageenan differ from agar which contains
sulphated esters but carrageenan also contains 20-
40% sulphite on dry weight basis.
■ Uses: emulsifying, stabilizing, gelling agent and
viscosity builder
■ Tooth paste, creams, lotions, cosmetic
manufacturing
■ Food industry, 0.5-1% concentration
40. Carrageenan
■ Incompatibility: ca react with cationic materials
■ Method of sterilization: dry heat sterilization,
maintaining at 150 degree C for 1 hour.
41. Xanthan Gum
■ Source: a polysaccharide produced by certain
species of bacteria. It is produced by pure
fermentation of glucose using the bacterium named
as Xanthomonas compestris, which is non toxic and
non pathogenic to human beings.
■ The high molecular weight polysaccharide produced
in culture broth is isolated by using isopropyl alcohol,
which is dried and milled to give commercial xanthan
gum.
■ Description: cream coloured powder, odourless,
soluble in cold and hot water giving highly viscous
solution, this is stable towards change in pH and also
to heat.
■ The aqueous solution of xanthan gum forms films on
evaporation. Aq. Solutions are pseudoplastic.
42. Xanthan Gum
■ Chemical nature: D-glucose, D-mannose and D-
glucuronic acid with short side chains.
■ Additionally pyruvic acid is present as side chain to
the extent of 2.5-4.8 % of molecule.
■ Xanthan gum is available in the market as its sodium
or potassium salts.
■ Sterilization: by autoclaving
■ Uses: very good emulsifying agent, stabilizer,
thickener, viscosity enhancer, food and cosmetic
industry
■ Storage: well closed container in a cool, dry place
43. Natural disintegrants
■ Disintegrants are agents added to tablet (and some
encapsulated) formulations to promote the breakup
of the tablet (and capsule “slugs’) into smaller
fragments in an aqueous environment thereby
increasing the available surface area and promoting
a more rapid release of the drug substance.
■ There are three major mechanisms and factors
affecting tablet disintegration as follows:
■ Swelling
■ Porosity and capillary action
■ deformation
44. Natural disintegrants
Advantages:
■ Effective in lower concentrations than starch
■ Less effect on compressibility and flow ability
■ More effective intragranular
Disadvantages:
■ More hygroscopic (may be a problem with moisture
sensitive drugs)
■ Some are anionic and may cause some slight in-vitro
binding with cationic drugs (not a problem in-vivo.)
45. Herbal disintegrants
Ideal characteristics
■ The ability to interact strongly with water is essential
to disintegrant function.
■ Combinations of swelling and/or wicking and/or
deformation are the mechanisms of disintegrant
action.
■ Super disintegrants offer significant improvements
over starch.
■ But hygroscopicity may be a problem in some
formulations.
46. Guar Gum
■ Syn: Guar galactomannan
■ Source: ground endosperms of seeds of Cyamopsis
tetragonolobus, family: Leguminosae
■ Description: white to pale yellowish white free
flowing powder, characteristic odour
■ Solubility: Slightly soluble in water and not in
organic solvents, dispersible in hot and cold water
and form colloidal solution, practically insoluble in
oils, grease, hydrocarbons, ketones, esters and 95%
ethanol.
■ Constituents: 85% Guaran (water soluble
polysaccharide) hydrolysis, galactose, mannose
■ Chemical test:
■ Gum + 2% lead acetate ppts
47. Guar Gum
■ Method of sterilization: autoclaving
■ Use: tablet binder (up to 10%), disintegrating agent,
suspension, emulsion (up to 1%), lotions, creams (up
to 2.5%), food and cosmetic industry as stabilizer
■ Oral hypoglycemic agent
■ Storage: well closed container in cool dry place.
Methyl paraben (0.75%) or propyl paraben (0.02%)
can be used as preservatives.
48. Starch
■ Syn: Amylum
■ Polysaccharide granules obtained from the grains of
■ Maize (Zea mays)
■ Rice (Oryza sativa)
■ Wheat (Triticum aestivum), Gramineae
■ Potato (Solanum tuberosum), Solanaceae
■ Description: very fine powder, white or slightly
yellowish powder or irregular, angular white masses
readily reducible to powder, which cracks when
pressed between the fingers. Odourless,Tasteless
■ Microbial limitation: 1.0 g is fee from E.coli and
Salmonella
49. Starch
■ Solubility: practically insoluble in cold water and cold
ethanol. At 37 degree C, starch swells in water by
about 5-10%.
■ Constituents: water soluble Amylose & water
insoluble Amylopectin which swells and responsible
for gelatinizing property of starch
■ Method of sterilization: auto claving
■ Uses: 5-25% w/w as binder, 3-15 % as disintegrants,
diluent for potent drugs to facilitate subsequent
mixing process
■ Storage: an air light resistant container in a cool, dry
place
50. Perfumery agents
■ Perfume compositions usually include an active
ingredient or enhancer and one or more adjuvants
such as extenders, antioxidants, fixatives, etc.
■ An active ingredient is a compound which imparts
the aroma to the perfume compositions or enhances
or augments the aroma of an existing perfume
composition.
■ Fixatives and extenders are not considered to be
active ingredients; an fixative slow down the rate of
evaporation of a perfume by reducing the volatility,
and an extender increases the volume of the
perfume composition without diluting the aroma.
52. Sandal wood oil
■ Syn: Chandan
■ Source: volatile oil obtained by steam distillation of
heartwood of Santalum album, Santalaceae
■ Description: nearly colourless golden yellow liquid,
pleasant sweet woody persistent odour. It is
somewhat oily, viscous liquid which is heavy in
weight and affected by light
■ Solubility: soluble in 5 volumes of 70% alcohol
■ Constituents: Sesquiterpene alcohol, Alpha and beta
santalol
■ Method of sterilization: bacteriological filtration
53. Sandal wood oil
■ Uses: perfumery industry for lavender perfume for
hair oil, face cream. Manufacture of dhoop, agarbatti
etc.
■ Disinfectant for genito-urinary tract
■ Cosmetic preparation
■ Storage: tight and light resistant container
54. Rose oil
■ Syn: Otto of rose
■ Source: volatile oil distilled from fresh flowers of
Rosa gallica and other Rosa species, Rosaceae
■ Description: colourless or yellow liquid with
characteristic odour of rose, at 25 degree C its
viscous liquid, upon gradual cooling it changes to
translucent, crystalline mass which maybe easily
liquefied by warming
■ Solubility: 1 ml rose oil miscible in 1 ml CHCl3
■ Constituents: solid-linalool, Liquid-nerol, citronellol
and geraniol
55. Rose oil
■ Chemical test: 1 ml rose oil + 1 ml CHCl3, add 20 ml
90% alcohol, the resulting liquid is neutral or acid to
moistened litmus paper and standing at 20 degree C.
It deposits a crystalline residue within 5 minutes.
■ Uses: flavouring agent in Perfumes
■ Storage: well filled containers in cool place
56. Flavouring agents
■ Flavouring agents are key food additives with
hundreds of varieties like fruit, nut, seafood, spice
blends, vegetables and wine which are natural
flavouring agents.
■ Flavouring agents include flavour substances, flavour
extracts or flavour preparations, which are capable
of imparting flavouring properties, namely taste or
odour or both to food. Flavouring agents may be of
following three types:
■ Natural Flavours and Natural Flavouring substances
means flavour preparations and single substance
respectively, acceptable for human consumption,
obtained exclusively by physical processes from
vegetables, for human consumption
57. Flavouring agents
■ Nature-Identical Flavouring Substances means
substances chemically isolated from aromatic raw
materials or obtained synthetically; they are
chemically identical to substances present in natural
products intended for human consumption, either
processed or not.
■ Artificial Flavouring Substances means those
substances which have not been identified in natural
products intended for human consumption either
processed or not.
59. Cardamom oil
■ Syn: Ilayachi tel
■ Source: volatile oil distilled from the seeds of
Elettaria cardamomum, Zingiberaceae
■ Description: colourless or pale yellow liquid with a
pleasant aromatic odour
■ Solubility: 1 ml of cardamom oil dissolves in 5 ml of
70% alcohol at 20 degree C
■ Constituents: Cineol, alpha terpinyl acetate,
terpeneol, borneol, sabinene etc
■ Uses: aromatic, carminative, stimulant and
flavouring agent
60. Cardamom oil
■ Cardamom oil finds application in flavouring
processed foods.
■ It is even used in liquid products like cordials, bitters
and liquors and occasionally in perfumery
■ Method of sterilization: bacteriological filtration
■ Storage: very tight, light resistant container and not
exceeding 25 degree C
61. Orange oil
■ Syn: Aurantii
■ Source: volatile oil obtained by expression from the
fresh peels of the ripe fruits of Citrus limonis,
Rutaceae
■ Description: an intense yellow orange or deep
orange liquid, characteristic odour
■ Solubility: miscible with dehydrated alcohol and with
carbon disulphide. One volume of orange oil
dissolves in 1 volume of glacial acetic acid
■ Constituents: 90% Limonene, citral, citronellal
■ Chemical test: solution of recently expressed orange
oil in dehydrated alcohol is neutral to moistened
litmus paper.
62. Orange oil
■ Method of sterilization: bacteriological filtration
■ Storage: well filled, well closed containers in cool
place away from sun light.
■ Note: don’t use orange oil that has terebinthinate
(Like turpentine) odour