This document discusses the bioassay of adsorbed diphtheria vaccine. It begins with introductions to bioassay, vaccine, and adsorbed diphtheria vaccine. It then describes the principles of bioassay, including comparing the test substance to an international standard. It outlines the preparation of standard and challenge toxins. The lethal challenge method is then described, involving injecting toxin-vaccine mixtures into guinea pigs and observing for erythema. Determination of vaccine potency involves comparing the doses needed to protect animals from the lethal toxin effect between the test and standard vaccines. The validity requirements include the protective doses falling within a specified range.

1. S U B M I T T E D T O - P R O F . S A N D H Y A B A W A .
S U B M I T T E D B Y - S K A Z I Z U D D I N .
C O U R S E - M . P H A R M .
D E P A R T M E N T - P H A R M A C E U T I C A L A N A L Y S I S
B A T C H - 2 0 2 0 - 2 0 2 2 .
C O L L E G E N A M E - J A M I A H A M D A R D .
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BIO ASSAY OF ADSORBED
DIPHTHERIA VACCINE.

2. • I N T R O D U C T I O N { B I O A S S A Y & V A C C I N E }
• P R I N C I P L E O F A S S A Y
• S E L E C T I O N O F C H A L L E N G E T O X I N
• P R E P A R A T I O N O F S T A N D A R D T O X I N
• P R E P A R A T I O N O F C H A L L E N G E T O X I N
• L E T H A L C H A L L E N G E M E T H O D
• D E T E R M I N A T I O N O F P O T E N C Y O F T H E
V A C C I N E
• V A L I D I T Y O F T E S T
CONTENTS.
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3. What is ASSAY?
 Amount or activity of an active principle in unit
quantity of preparation.
 TYPES;-
Physico-chemical
assay
Biological assay
Immunological assay
RIA
ELISA
Photometry
chromatography
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4. BIOASSAY
 DEFINITION
Potency or concentration of an active principle in
unit quantity of preparation.
By measuring its biological response on living tissue.
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5. PRINCIPLES OF BIOASSAY
To compare the test substance with the
international standard preparation of the
same.
To find out how much test substance is
required to produce the same biological
effect as produced by the standard.
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6. CONTINUE.....
 Vaccine- A preparation of killed microorganisms, living
attenuated organisms, or living fully virulent organisms
that is administered to produce or artificially increase
the immunity to a particular disease.
 Adsorbed Diphtheria vaccine-.It is an anti-toxin
preparation containing anti-toxic globulins that have
the power of specifically neutralizing the toxin formed
by corynebacterium diphtheria.
 It is obtained by fraction of horse or other mammal
serum, that have been immunized against Diphtheria
toxin.
 Diphtheria vaccine is generally available in the
combination with tetanus and pertusis vaccine DPT.
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7. Cont...
Diphtheria vaccine( adsorbed) is a sterile suspension prepared by mixing
purified diphtheria formol toxoid+ mineral carries[which is hydrated
aluminium hydroxide[or]calcium Po4 ] in saline solution or other suitable
solution isotonic with blood
Diphtheria
formal Toxoid
Mineral carrier
such as
Aluminium,
Ammonium
hydroxide etc.
Adsorbed Diphtheria
Vaccine[ADV]
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8. ADSORBED DIPHTHERIA
VACCINE.
Diphtheria
formol
toxoid+mineral
carrier[which is
hydrated
Aluminium
toxoid or
Calcium PO4 ]
Adsorbed Diphtheria
vaccine
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9. CONT......
 Antigenic properties of ADV is adversely
affected by anti-microbial preservatives such
as;-
Phenol type and these should not added to
the vaccines.
{ADV is prepared from diphtheria formol
toxoid and it contains not less than
1500Lf/mg of protein nitrogen and mineral
carrier}.
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10. Cont......
Scientist learned to
harness the immune
systems of some animals
to produce antitoxin
serums to use in
medicines. Diphtheria
antitoxin was one of
these medicines. Doctors
used diphtheria antitoxin
to treat and prevent
diphtheria an often
deadly childhood disease
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11. PRINCIPLE OF ASSAY:
 The potency of Diphtheria antitoxin is determined by comparing the
dose necessary to protect the guinea pig or rabbit against the
erythrogenic effect of a fixed dose of the standard preparation of
Diphtheria toxin.
 A. INTRADERMAL CHALLENGE METHOD-
 PRINCIPLE-;The potency of adsorbed diphtheria
vaccine is determined by comparing the dose is
necessary to protect guinea pig against the
erythrogenic effect of range of intradermal injection
of diphtheria toxin with dose of the standard
preparation of adsorbed diphtheria toxin necessary
to give the same protection.
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12. CONTINUE....
 PROCEDURE-:
 Standard preparation-: Standard preparation
consisting of toxoid adsorbed on a aluminium
hydroxide with polygeline.
 Test animal-:White guinea pig
weight between 250-350gm
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13. CONTINUE.....
 Selection of challenge toxin-:
Selection of preparation of diphtheria toxin
containing 67-133lr/100 in limes flocculation (Lf)
and 25000-500000 minimal reacting doses for
guinea pig skin in 1LF(limes flocculation).
 Preparation of challenge toxin-:
Dilute challenge toxin with a suitable diluents to
obtain a challenge toxin solution containing 512×10-4
Lf in 0.2ml.
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14. DETERMINATION OF POTENCY OF VACCINE
Assay limits falls between 50% and 200% of the estimated potency.
After 48 hrs record the incidence of specific diphtheria erythema.
0.2 ml challenge toxin solution is inject to guinea pig intradermally.
After 28 days shave the both flanks of each guinea pig.
Inject guinea pig subcutaneously (5 months)
Vaccine is dilute with the saline solution
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15. LETHAL CHALLENGE METHOD:
 Test animal such as guinea pig, Horses , Rabbits are
selected for this.
 If guinea pig then it should be of 250-350 gm.
 The animal are grouped into 6 groups of 16 animals each
having same sex.
 0.2 ml of each mixture should be injected subcutaneously
or intradermally into the animal.
 The animals are observed after 48 hours for specific
Diphtheria erythema.
 Mixture containing larger amount of toxin will give
severe reaction and vice versa.
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16. PREPARATION OF STANDARD TOXIN
 It is prepared in a saline solution having 1ml
of preparation having 0.1 IU of toxin
followed by:
 1 ml of standard preparation along with 0.2
IU test toxin.
 1 ml of standard preparation along with 0.3
IU test toxin
 Store the preparation away from light.
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17. PREPARATION OF CHALLENGE TOXIN
 Challenge toxin/ preparation to be assayed is
diluted with phosphate buffer solution(PBS) of pH
7.4.
 The challenge toxin solution is diluted in the same
solution upto the following level:-
 2LD50
 LD50
 1/2LD50
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18. DETERMINATION OF POTENCY OF THE
VACCINE:
 The 3 dilutions of sample and standard vaccine are
prepared in saline solution each dilution difference
by 2.5 fold.
 Immediate conc. inject into guinea pigs
subcutaneously.
 This should protect 50% animals from lethal effect of
subcutaneous injection.
 Calculate the potency of the vaccine relative to the
potency of standard preparation on the basis of the
number of animals survived in each group of 16
animals.
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19. CONTINUE...
After 4 days count the number of survival animals
1 ml inject to 4 groups of 5-guinea pigs- subcutaneously
Test challenge toxin dilution
After 28 days
Allocate 6 dilutions, one to each of the 6 groups of 16 guinea pigs(1ml)
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20. VALIDITY OF TEST:
 Vaccine under examination and standard
preparation, the 50% protective doses lies between
the largest and the smallest doses of the preparation
given to guinea pigs.
 Mortality increases when increases in toxin dose
level is there the minimum amount of toxin which
when combined should cause a local skin reaction
that is just visible and indicates the presence of
toxin.
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21. ACRONYMS
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 Lf- limes flocculation
 RIA- Radio immunoassay
 Elisa- Enzyme linked immunoassay
 ADV- Adsorbed diphtheria vaccine
 LD- lethal dose
 PBS- Phosphate buffer solution
 I.U- International unit
 Lr dose- limes reacting dose

22. REFERENCES
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 Indian pharmacopeia 2007 : volume-3
 Google search( slide share)

23. THANK YOU
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