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APPLICATION OF
BUFFERS,BUFFERS EQUATION
AND BUFFER CAPACITY
PRESENTED BY – RAJDEEPA KUNDU(39)
DIVYA VISHWAKARMA(24)
CONTENT
*WHAT IS BUFFER
*PRINCIPLE OF BUFFERING
*BUFFER CAPACITY
*BUFFER EQUATION
*APPLICATION OF BUFFER
WHAT IS BUFFER:
 A BUFFER SOLUTION IS AN AQUEOUS
SOLUTION CONSISTING OF A MIXTURE
OF WEAK ACID AND ITS CONJUGATE
BASE OR VISE VERSA.ITS PH CHANGES
VERY LITTLE WHEN A SMALL AMOUNT
OF STRONG ACID OR BASE IS ADDED
TO IT.BUFFERS SOLUTIONS ARE USE
AS A MEANS OF KEEPING PH AT A
NEARLY CONSTANT VALUE IN A WIDE
VARIETY OF CHEMICAL
APPLICATIONS.
PRINCIPLES OF
BUFFERING
Buffer solutions achieve their resistance to ph
change because of the presence of an
equilibrium between the acid HA and its
conjugate base A−.
HA ⇌ H+ + A−
When some strong acid is added to an
equilibrium mixture of the weak acid and its
conjugate base, the equilibrium is shifted to the
left, in accordance with la chateliers principle.
Because of this, the hydrogen ion concentration
increases by less than the amount expected for
the quantity of strong acid added. Similarly, if
strong alkali is added to the mixture the hydrogen
ion concentration decreases by less than the
amount expected for the quantity of alkali added.
BUFFER CAPACITY
• Buffer capacity, β, is a quantitative measure of
the resistance of a buffer solution to pH change
on the addition of hydroxide ions.
• where dCb is an infinitesimal amount of added
base.
• d is the resulting infinitesimal change in the
COLOGARITH of the hydrogen ion
concentration.
BUFFER EQUATION
• Buffer capacity is the capacity of a buffer solution to
resist change in its pH. The equation is given by, pH =
pKa + log [Salt] / [Acid]
• The pH of any acidic buffer solution is always less than
7 and the pH of any basic buffer solution is always
greater than 7.
APPLICATION OF BUFFER
 BUFFERS ENSURE THE STABILITY OF
DRUG THROUGH OUT THE SHELF
TIME OF THE PRODUCT.
 PARENTERAL PREPARATION:
LARGE DEVIATION OF PH IN CASE OF
PARENTERAL PREPARATION CAUSE
SERIOUS CONSEQUENCES .THE
MOST COMMONLY USED BUFFERS IN
PARENTERAL PRODUCTS ARE
ACETATE,PHOSPHATE,CITRATE,GLU
TAMATE.
OPTHALMIC
PREPARATION:
 OPTHALMIC PREPARATION
INCLUDE EYE DROPS,EYE
SOUTION EYE LOTIONS ETC
.BUFFERS ARE GENERALLY USED
PREPARED TO TO MAINTAIN THE
PH OF LACRIMAL FLIUIDS.THE
BUFFERING AGENTS MOST
COMMONLY USED IN OPTHAKMIC
PREPARATION INCLUDE
BORATE,CARBONATE
,PHOSPHATE.
BIOLOGICAL USE
 PRIMARY BUFFERS IN BLOOD
PLASMA:THE PH OF BLOOD IS 7.4.
CARBONIC ACID,ACID OR ALKELYNE
SODIUM SALT OF PHOSPHORIC ACID
HELPS TO MAINTIAN THE PH OF
BLOOD.
 SECOENDARY BUFFERS IN
ERYTHROCYTE:OXY HB,ACID OR
ALKELINE POTASSIUM SALT OF
PHOSPHORIC ACID WORKS AS
BUFFER
 FERMENTATION PROCESS:
In industry, buffering agents are used
in fermentation processes and in
setting the correct conditions for dyes
used in colouring fabrics. They are
also used in chemical analysis and
calibration of pH meters.
THANK YOU……