Application of buffers,buffers equation and buffer capacity

APPLICATION OF BUFFERS, BUFFERS EQUATION, AND BUFFER CAPACITY

1. APPLICATION OF BUFFERS,BUFFERS EQUATION AND BUFFER CAPACITY PRESENTED BY – RAJDEEPA KUNDU(39) DIVYA VISHWAKARMA(24)

2. CONTENT *WHAT IS BUFFER *PRINCIPLE OF BUFFERING *BUFFER CAPACITY *BUFFER EQUATION *APPLICATION OF BUFFER

3. 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.

4. 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.

5. 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.

6. 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 .

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,GLUTAMATE.

8. 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.

9. 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

10. 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.

11. THANK YOU……