The document discusses the significance of water in the pharmaceutical industry, covering its physical and chemical properties, types of hardness, and methods for softening hard water. It explains different purification processes, including demineralization and sterilization for water used in injections, and details on the solubility of pharmaceuticals affected by various factors. It highlights the importance of selecting suitable water types based on requirements for usage in parenteral preparations.

1. Water
PRESENTED BY
MS. MONIKA P. MASKE
ASSISTANT PROFESSOR
M. PHARM
(PHARMACEUTICAL CHEMISTRY) 1

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3. Introduction
• Water is most widely required solvent for any industry.
• Pharmaceutical industry requires different types.
• Water is present in three physical state i.e. solid, liquid, gas.
• Water occupies about three quarter of surface of earth.
• Potable water fit for human consumption which are available on lands under the
surface of earth and from rivers, dams, etc.
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4. Physical Properties of water
• Water is clear liquid, colourless and without odour.
• When freeze at 0⁰ C to form ice which floats on water.
• When heated to 100⁰C it convert to steam.
• It has high boiling point and freezing point.
• Water possess dipole moment and dielectric dipole.
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5. Chemical properties of water
1. Thermal stability- under ordinary condition water is chemically stable.
2. Ionic dissociation- the dissociation constant varies directly with temperature.
3. Solvent property- its important property. Water act as solvent for wide range
of substance because water have high dielectric constant and polarity.
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6. 4. Hydration- it follows “like dissolves like”, because of strong permeant
dipole, water act as ligand in formation of complex.
5. Amphoteric character- water act as solvent in acid-base reactions.
6. Redox property- water act as oxidizing agent.
7. Catalytic property- water act as catalyst and play important role in reactions
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7. Hardness of Water
• The nature & amount of chemical salts present in the water, hardness is given to
water.
• It define as, the property of water to form an insoluble curd with soap instead of
leather.
• In other words it’s the soap destroying property due to presence of
bicarbonates, sulphates, chlorides and magnesium.
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8. water
Temporary
Hardness
Its due to presence of bicarbonates of calcium &
Mg and removed by Boiling
o- easily removed by heating
Permanent
Hardness
Its due to the presence of sulphates, nitrates &
chlorides of calcium & magnesium
- Cannot removed simply by boiling
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10. Units of Hardness
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11. Methods of Softening of hard water
The following softening methods are used:
1. Lime soda process
2. Zeolite softening process
3. Ion exchange process
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12. 1. Lime soda process
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15. 2. Zeolite softening process
• Water containing calcium or Mg ion is passed through
column containing zeolites, ions are retained by zeolite &
sodium ion is exchanged.
• The process of water softening occurs.
• Zeolite now replaced by ion-exchange resin.
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16. 3. Ion exchange process
• For demineralization of water, this method is used.
• Resin contained acidic group which act as cation exchange & having basic group
as anion exchangers.
• The cation & anion exchange resin are filled in tubes, columns or bed and water
is passed through them.
• The exchange phenomenon the cations like calcium, Mg present in water are
exchanged with H+ or Na+ ion present on cation exchange resin.
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18. Natural & Portable Water
• Natural water or rain water is purest form of water.
• When water falls down into soil during this large number of salts, ions, gases get
dissolved into it.
• The soil particles, plants, animals debris and various kind of organisms, waste
ultimately introduce impurities.
• For drinking purposes as well as industrial use some treatment is necessary.
• Depending upon the source of water, kind, type of impurities.
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19. • For soil particles, plants, animal debris the suspended particle treatment and
filtration is carried out.
• Drinking purposes chlorination, fluorination etc. are carried out.
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20. Sterile Water for Injection
• Its suitably packed.
• Should not contain any antimicrobial agent or other added substances.
• It should comply all test described for purified water & water for injection as
per IP.
• It comply test for sterility.
• It should supplied in single dose container.
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21. Water for Injection
• Water prepared by distilling portable water from natural glass or metal still
fitted with device for preventing the entrainment of droplets.
• First distillate and distillate water collect in suitable containers & sterilised in an
autoclave or by filtration without adding bacteriostatic agents.
• Water should comply purified water and test for pyrogens.
• It should stored in tightly closed containers.
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22. • Its used as a solvent preparation of parental solution which are sterilised after
preparation.
• No sterility test.
• If parental solution is to be prepared under aseptic conditions & not sterilized in final
container, every care should taken to protect water from bacterial contamination.
• Every care of aseptic technique is followed in its preparation by distillation method.
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23. Purified Water
• Purified water prepared from suitable portable water by distillation or using ion-exchange
resins.
• Distillation apparatus is used for distillation.
• Distilled water is purified water.
• In this technique dissolved solids & non-volatile matter or impurities get removed.
• obtained distilled water of high purity with special chemical treatment.
• The demineralised method depends on used of ion-exchange resins.
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24. • Demineralised water is free from mineral salts.
• Purified water should have 4.5 – 7.
• it should comply test for CO2, NH3, nitrate, chloride, calcium, sulphate, heavy metals.
• Total solids not exceeding 0.001%.
• Stored in tightly closed container and when distilled water is prescribed, purified water
should be supplied.
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25. Selection of Suitable Water for Use
• Potable water is cheapest, demineralized is next cheapest, than distilled & sterile water, water
for injection.
• For parenteral used the potable water.
• Limits of total solids, pH, bacterial purity all check for selection of water for purpose.
• The pH of water should consider when pH sensitive substances, like chlorinated water used
which has acidic pH.
• Purify and potable water for parental use required same limits like pyrogen test, sterility.
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26. • For precreation of solution it should comply sterility test.
• All requires to comply with good manufacturing practices.
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27. Solubility of Pharmaceuticals
• The term solubility is referred as the concentration of dissolved solute at an
equilibrium at saturation point.
• When the concentration of any solute in a liquid more the solubility, results in
ppt. or stage of supersaturation.
• Solvents with high ionic or polar character dissolve most substances.
• Solvents with low dielectric constant or polarity are less effective in solubility.
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28. Methods of Expression of Solubility
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Solubility Ratio

29. • Normal solution (N)-
When solution contains 1 g equivalent weight of a substance per litre, its called
as normal solution.
• Molar solution (M)-
A solution containing 1 mole per thousand ml of solution is called as molar solution.
• Molal solution- a solution containing 1 mole of solute per thousand g of solvent.
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30. Factors Affecting Solubility
1. Influence of Temperature & Pressure-
• Solubility of salts or solute molecule is temperature dependent.
• Solubility increases with increases in temperature.
• Pressure also affect solubility.
• Solubility increase with increase in pressure.
• When pressure is reduced the dissolved solute escapes out from the solution.
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31. 2. Influence of Other Salts/Solutes-
• Solubility may affect by other dissolved substances.
• This effect more when forging substance present in high concentration.
• This produced change in dielectric constant of solvent.
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32. Thank You
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