In the pharmaceutical inorganic chemistry as per PCI for B-pharm FY students easy to understand the topic is Acid and base

1. 1

2. 2
Acid Base & Buffer

3. CONCEPT OF ACID & BASE
Acid:
Any substance which posses the following characteristic
will classified as acid
1. Blue litmus turns red
2. Taste Sour
3. Conduct electricity
4. Cancel the effect of base
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4. CONCEPT OF ACID & BASE
Base:
Any substance which posses the following characteristic
will classified as base
1. Red litmus turns blue
2. Taste bitter
3. Conduct electricity
4. Cancel the effect of acid
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5. CONCEPT OF ACID & BASE
EXAMPLES OF ACID ?????
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6. CONCEPT OF ACID & BASE
Acid:
1. Hydrochloric acid (HCl)
2. Nitric acid (HNO3)
3. Sulphuric acid (H2SO4)
4. Acetic acid (CH3COOH)
5. Boric acid (H3BO3)
6. Phosphoric acid (H3PO4)
7. Carbonic acid (H2CO3)
8. Ferrous Sulphate (FeSO4)
9. Copper Sulpahte (CuSO4)
10. Carbon dioxide (CO2)
11. Hydrogen Sulphide (H2S)
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7. CONCEPT OF ACID & BASE
EXAMPLES OF BASE ?????
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8. CONCEPT OF ACID & BASE
Base :
1. Sodium Hydroxide (NaOH)
2. Potassium Hydroxide (KOH)
3. Sodium Carbonate (Na2CO3 )
4. Ammonia (NH3)
5. Ammonium Hydroxide (NH3OH)
6. Lithium Hydroxide (LiOH)
7. Dihydrogen Phosphate (H2PO4)
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9. THEORIES
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10. ACID & BASE
Acid & base can be explained by certain theories.
1. Arrhenius theory
2. Lawry Bronsted theory
3. Lewis theory.
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11. 1. Arrhenius Theory
Acid:
It may be defined as hydrogen containing substance which
dissociates to gives H + ion aq. Solution.
e.g.
1. HCl + H2O H+ + Cl-
2. CH3 COOH + H2O H+ + CH3 COO-
Base:
It may be defined as hydroxyl compound which dissociates to
gives OH – ion in aq. solution.
NaOH + H2O Na+ + OH-
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12. 1. Arrhenius Theory
Limitation:
1. Aqueous: defined only in their aq. Sol & not in non aq.
Solvents or in gaseous state.
2. Non Hydroxy: According to Arrhenius theory base is
hydroxy compound , however some non hydroxyl
compound like NH3 , Na2CO3, KCN, CH3COONa . Arrhenius
theory fails to explain basic nature of such non hydroxy
compound.
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13. 1. Arrhenius Theory
Limitation:
3. Non Hydrogen : According to AT acid is Hydrogen
containing sub but non hydrogen sub are like CO2 , FeCl3 ,
CuSO4 etc. are also acidic in nature.
4. According to AT H + ions exist in aq. solution which is not
true, because H + ions are always hydrated i.e. combines
with H2O mol. Introduce hydronium ions.
H+ + H2O H3O +
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14. 2. Lowry Bronsted Theory
Acid:
The substance can donate the protons to solution is called as
acid
HA H + + A-
HCl H+ + Cl –
H2SO4 H+ + HSO4 –
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15. 2. Lowry Bronsted Theory
Base:
The substance which can accept the protons called as base.
B: + H+ BH+
OH - + H+ H20
H20 + H+ H30 +
SO4
2- + 2H + H2SO4
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16. 2. Lewies Theory
Acid:
The substance which can accept the lone pair of electrons
e.g. HCl, H2SO4
Base:
The substance which can donate the lone pair of electrons.
e.g. NaOH , KOH
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17. BUFFER
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18. BUFFER
Buffer Solution :
The solution which resist change pH upon addition of
small amount of acid or alkali are called buffer solutions.
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19. 19
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Buffer
On the
basis of
Chemical
Nature
Analytical Buffer Pharmaceutical Buffer
1. Physiological Buffer: Phosphate B Protein B,
Carbonate B
2. Actual Buffer : Borate B, Acetate B
1. Acidic Buffer
2. Basic Buffer
3. Neutral Buffer

20. BUFFER
1. Acidic Buffer : It is combination of weak acid & its corresponding salt.
e.g. Mixture of acetic acid, sodium acetate.
2. Basic Buffer: It is combination of weak base and its corresponding salt.
e.g. mixture of Ammonium hydroxide and ammonium chloride .
3. Neutral Buffer: It is single substance showing the properties of buffer.
e.g. ammonium acetate.
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21. MECAHNISM OF BUFFER SOLUTION
Acidic Buffer: In any mixture of weak acid and its salt.
1. The acid determines the hydrogen ion concentration of solution. in case of acetic
acid mixture and sodium acetate.
2. The solution contain high concentration of unionized acetic acid & that of
acetate ions.
3. If little quantity of strong acid as HCl is added to the solution. H + Ions reacts
with acetate to form unionized acetic acid .
CH3COONa CH3COO- + Na+
CH3COO- + Na+ + H+ (From HCl) CH3COOH
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22. MECAHNISM OF BUFFER SOLUTION
5. As a result of there is little changes in H + ions concentration i.e. pH of solution . On
the other hand , if base such as NaOH is added , the OH- ions will reacts with
hydrogen ions already in the solution
CH3COOH + OH- H2O + CH3COO-
6. Again the hydrogen ion concentration changes only little. Thus Sodium acetate
neutralize the added H+ while acetic acid neutralize by OH- ions. 0
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23. MECAHNISM OF BUFFER SOLUTION
Basic Buffer:
1. In case mixture of weak base NH4OH & its salt NH4Cl , the buffer mixture contain a
large concentration of unionized molecules of NH4OH along with NH4+
NH4OH NH4
+ + OH-
NH4Cl NH4
+ + Cl-
2. When a strong acid is added to such solution , the H + ions thus introduced are
neutralized by ammonium hydroxide and there is no change in pH value.
NH4OH + H + NH4
+ + H2O
3. On addition of base , the hydroxyl ions reacts with NH4 to form NH4OH and there is
again practically no changes I pH of solution.
OH- (added from base ) + NH4
+ NH4OH
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24. BUFFER
Buffer Capacity :
It is defined as the moles of strong acid or strong base required
to change the pH of 1 lit of solution by 1 unit.
Properties of buffer:
1. The pH of buffer solution is constant.
2. The pH of buffer does not changes on dilution.
3. The pH does not changes even after addition of small
quantities of acid or bases.
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25. BUFFER
Factors considered for Selection of Buffer:
I. Chemical Factors
II. Pharmaceutical Factors.
I. Chemical factors:
1. The buffer system should not react with other chemicals in
the preparation.
2. The buffer system should have reasonable chemical stability.
3. Buffer capacity depends on absolute concentration of each
buffer compound.
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26. BUFFER
Factors considered for Selection of Buffer:
II. Pharmaceutical Factors.
1. Toxicity of buffers: Some of the buffers have limited use in
pharmaceutical practice because of their toxicity.
2. Effect on pharmacological action of the preparation:
Buffer system should not interact with action of ingredients
of preparation.
3. Contamination by microorganisms: Many buffer systems
support microbial growth as they can serve as nutrient
media for moulds and microorganisms particularly when the
pH is close to neutrality.
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27. ROLE OF BUFFER
1. The buffers are important in pharmaceutical preparation to
ensure stable pH conditions for the medicinally active
compounds.
2. Solubility of many compounds is controlled by providing a
suitable pH.
3. Color of many compounds is pH-dependant.
4. pH gives stability of different preparations.
5. It provides patient comfort.
6. Citric acid is used for stabilizing milk of magnesia.
7. Penicillin preparations are stabilized by addition of
carbonates.
8. +Sulphonamide preparations are stabilized by addition of
sodium bicarbonate, sodium acetate or sodium citrate.
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28. Distinguish between phosphate buffer and borate buffer.
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Sr.
No
Phosphate Buffer Borate Buffer
1. It is composed of monohydrate and
dihydrogen phosphate.
It consists of tetra borate ion and
boric acid.
2. It is non-toxic Toxic, if taken internally.
3. pKa is 7.2 pKa is 9.2.
4. It is useful for internal preparations and
parenteral preparations.
It is generally used for external
preparations only

29. 1. Boric Acid:
Boric Acid:
Synonym: Orthoboric acid.
Formula: H3BO3
Properties:
1. Color: white
2. Odour: odorless powder
3. Taste: bitter taste
4. It is soapy to touch.
5. Solubility: Soluble in hot water and freely soluble in
glycerin.
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30. 1. Boric Acid:
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Storage: it should be stored in well closed container.
Label: Label should indicate:
“It should not be taken internally.”
“It should not be applied on broken skin.”
Incompatibility: It is incompatible with tannins.
Uses:
1. Externally for irrigation of organs.
2. Cleaning of wounds.
3. Mild antiseptic
4. In dusting powders.
5. Ingredient of mouthwash and eyewash.
6. Buffer in ophthalmic preparations.
7. To reduce inflammation of various skin disorders.

31. 2. Sodium Hydroxide
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Synonym: Caustic soda.
Formula: NaOH
Properties:
1. Color: White odorless salt.
2. Nature: Available in pellets form
3. Solubility: Soluble in water and alcohol
4. It is a very strong base.
Storage: It is stored in tightly closed container as it absorbs
moisture and carbon dioxide.
Uses:
1. As a laboratory reagent.
2. In the preparation of soap.

32. 3. Strong Ammonium Hydroxide
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 Synonym: Strong ammonia solution, liquor ammonia fortis.
Formula: NH4OH
Properties:
1. Color: colorless liquid
2. Odour: pungent odour.
3. Taste: Alkaline in taste.
4. Miscibility: Miscible with water.
5. Reacts with metal to from nitrogen gas.
Storage: in a tightly closed container in cool place.
Label: “Handle with care” “Do not taste”. “Avoid inhalation of
vapours”.

33. 3. Strong Ammonium Hydroxide
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 Uses:
1. As a source of ammonia.
2. Antacid.
3. Counterirritant and respiratory stimulant.
4. As a fertilizer.
5. In preparations of aromatic spirit of ammonia.
6. As a laboratory reagent.

34. 4. Calcium Hydroxide
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 Synonym: Slaked lime Or Hydrated lime.
Formula: Ca (OH)2
Properties:
1. Color: White soft powder.
2. Taste: Bitter in taste.
3. Solubility: Slightly soluble in water. Insoluble in alcohol.
4. Aqueous solution is alkaline to litmus.

35. 4. Calcium Hydroxide
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Chemical Properties:
Calcium hydroxide is base and it is neutralise with acid to form salt.
+
Storage: it should be kept in tightly closed containers
protected from moisture.
Incompatibility: incompatible with co2
Ca (OH)2 Cl
2 H + 2 H20
2

36. 4. Calcium Hydroxide
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Uses:
1. As a source of calcium
2. As antacid.
3. As electrolyte replenisher.
4. Astringent in diarrhea.
5. Emulsifying agent in soap formation.
6. As ingredient of ointment and skin lotions

37. 5. Strong Ammonia Solution
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Formula: NH3
Properties:
1. It is clear, colorless liquid.
2. Odour: having an exceeding pungent, characteristic odour.
3. Its specific gravity is about 0.90.
4. Miscible with water in all proportion.
 Caution:
Strong ammonia solution should be handled carefully
because of its caustic nature of solution and irritating
properties of vapours. Cool the container well before
opening and cover the closure with a cloth of other material
while opening. Do not taste strong ammonia solution and
avoid inhalation of its vapours

38. 5. Strong Ammonia Solution
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Storage: Preserve ammonia solution (strong) in a well
closed container in a cool place.
Medicinal and Pharmaceutical uses:
1. Its salts are used as an antacid, counter irritant and
respiratory stimulant.
2. Dilute solution of ammonia (10%) is a common reagent
and a base.

39. 6. Hydrochloric Acid
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Synonym: Muriatic acid
Properities:
Physical :
 It is colourless liquid
Odour is Pungent
 specific gravity is 1.18
It is Miscible with water and alcohol.

40. 6. Hydrochloric Acid
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Chemical Properties :
i. +
ii. +
iii. +
Storage :
Store in Glass stoppered container at a temprature not exceeding 30 ° C
HCl NaOH + H2O
Zn 2 HCl 2 + H2
AgNO3 HCl + HNO3

41. 6. Hydrochloric Acid
Uses:
1. As an acidifying agent.
2. Pharmaceutical aid
3. In anemia with iron therapy.

42. THE END