Biopharmaceutics and Pharmacokinetics Practical Manual

1
BIOPHARMACEUTICS &
PHARMACOKINETICS
PRACTICAL MANUAL
RESHMA FATHIMA.K
ASSISTANT PROFESSOR
GRACE COLLEGE OF PHARMACY, PALAKKAD

2
EXP.NO:1
DATE:
INVITRO DISSOLUTION STUDY OF COMPRESSED TABLET
AIM
To study the invitro drug release of given compressed tablet of paracetamol.
REQUIREMENTS
Paracetamol pure, paracetamol tablets, sodium hydroxide, potassium hydrogen
phosphate, dissolution test apparatus, U.V spectrometer.
THEORY
Dissolution is defined as the amount of drug substance that goes into
solution per unit time of solvent composition.
It is one of the quality control tool for solid dosage form .The
bioavailability of a drug from its dosage form is dependent upon the dissolution
behavior of that drug and there by its pharmacological activity. The co-relation
between in vivo respondent dissolution is called in vivo-invitro correlation.
TABLET DISINTEGRATION SUSPENSION
CROSS THE MEMBRANE SOLUTION
&
REACH THE BLOOD
Various types’ dissolution test apparatus are official in B.P, I.P& USP.
TYPE -I Apparatus: Paddle
TYPE- II Apparatus: Basket
TYPE-III Apparatus: Basket
According to I.P
According to U.S.P

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TYPE-II Apparatus: Paddle
Choice of apparatus is effect on the physicochemical properties of
dosage form. Compression tablet are standard uncoated tablet made by direct
compression or wet granulation method they may used for local action on GIT
as systemic action. A drug product with rapid dissolution (compressed tablet)
one when greater than or equal to 85% of the labeled amount of drug dissolved
with on 13 minutes using U.S.P apparatus I &II in volume of less than or equal
to 900ml buffer solution.
PROCEDURE
a) Preparation of phosphate buffer of pH
5.8
Place 50ml of 0.2 M potassium hydrogen phosphate in 200ml volume of flask
add 3.6ml of 0.02M sodium hydroxide &then add water to make volume
b) Procedure for dissolution
1. Fill the dissolution vessel with dissolution medium (pH6.8
phosphate buffer) up to 900ml.
2. Set the parameter like rpm, temperature, time etc.
3. Once the temperature reaches to 370
c inside the tablet into the
vessel.
4. Withdraw sample at predetermine time interval 0, 5, 10, 15,
30,45min.
5. Filter dilute & measure the absorbance at 245nm.
6. Calculate the concentration of drug (µg/ml)&percentage drug
released.
7. Plot a graph taking time on x-axis and percentage during dissolve
on y-axis.

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REPORT
Invitro dissolution Calculation curve Standard solution
% of drug release of
tablet I 103.5% 99.7%
tablet II 105.4% 103.8%
tablet III 108% 105.3%
REFERENCES
 Laboratory manual of Biopharmaceutics &pharmacokinetics by V.B
Phase, R.J.Duas page no: 18-21
 Indian Pharmacopoeia 1996 vol I

5
EXP.NO:2
DATE:
INVITRO DISSOLUTION STUDY OF MARKETED SUSTAINED
RELEASE TABLET
AIM
To study the invitro drug release of given diclofenac sodium(sustained release).
REQUIREMENTS
Diclofenac sodium, dissolution medium, apparatus, U.V spectrophotometer
THEORY
SUSTAINED RELEASE TABLET
The main aim behind formation of this dosage form into the medicaments
for a long duration after administration of a single tablet.
A wide spread are of this type of tablet is mainly because of improvement in
the patent complaints as the dose frequency is reduced patient can be an
undisturbed sleep at night. It also beneficial for psychological patients who
forget to take their tablet regularly and the dose related side effect and toxicity
are reduced. Any adjuvants that can water uptake rate swelling and feeling
characteristics of matrixing agents can after the release of rate of API Eg:
electrolyte on hydroxyl propyl methyl cellulose (HPMC) matrix tablets. It’s also
possible to achieve pulsed drug release. Weakly basic drugs exhibits good
solubility at low pH while less soluble drugs shows at high pH, conditions
which can results on incomplete drug release co-sustained release formulation.
The drug release can be modified by providing suitable micro environment pH
in the tablet.
Eg: Acidic polymers, succinic acid etc.
Similarly inclusion of alkaline polymer results in desirable drug release of
acidic drug. Classic approaches are usually based on adaptation of either film

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coated or multiparticle technologies or those including slow release matrixes.
Which are discussed below
Coating technologies
It combines semi permeable coating and osmotic tablets core to produce zero
order release. Technology attention s also focused to triggered drug release at
critical time point Eg: To achieve drug release 1-2 hours before patient
awakeness also prolific research activities have yield a technology called ring
cap which is based on tab, preferentially film coated and partially coated with a
series of ring whose respective thickness provides the means of moderating the
rate which the drug is released from final dosage form.
Matrix technology
Classically the matrix products exhibits order (or perhaps sq. root of times).
Drug released characteristics in order to achieve zero order release
characterization it’s necessary to employed specially designed materials of
strategies that seen to manipulate tablet structures of geometry. Combination of
conventional HPMC matrix technology with upper and lower layer helps to
moderate drug release by increasing in surface area with reduction in drug
concentration within the device .Release of drug can follow various
mechanisms:
 Diffusion is rate limiting
 Dissolution is rate limiting
 Osmotic pressure is rate limiting
 Release is controlled by ion exchange
PROCEDURE
Dissolution test for commercial ibuprofen was performed using dissolution test
apparatus [USP 23] . In this paddle type was used to carry out the test.The set
condition was 900ml of purified water at temperature 370
c ± 0.50
C , 50 rpm. A
tablet was introduced into dissolution test apparatus. Samples were withdrawn

7
every 1hr and same volume of fresh dissolution medium was replaced. Samples
were diluted suitably and analyzed by UV spectrophotometer at 254nm.
Percentage drug release was found out by the following formula:
Percentage drug release =
𝑡𝑒𝑠𝑡𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒
𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒
× 100
REPORT
The percentage drug release from given ibuprofen 100mg at the end of 10hrs
was found to be
REFERENCES

8
EXP.NO:3
DATE:
DETERMINATION OF PARTITION COEFFICIENT AND
DISSOCIATION CONSTANT
AIM
To determine Ka, pKa and partition coefficient (pc) value of salicylic acid and
study their relationship
REQUIREMENTS
Separating funnel, 10ml standard flask, u.v spectrophotometer
THEORY
Salicylic acid is a relatiely polar, poorly aqueous soluble material. The salt form
however is quite water soluble by changing PH of the aqueous buffer, you are
able to alter the ratio between the ionized and unionized form of the acid. Since
the unionized form is extracted into the organic phase, the fraction extracted
will vary with PH of the aqueous solution. The definition of ionization constant
(Ka) can be useful.
In aqueous buffer H+
Ka=
[𝐻+][𝐴−]
[𝐻𝐴]
OR 𝐾𝑎
[𝐻𝐴]
[𝐻+]
The partition coefficient is a ratio of concentrations of un-ionized compound
between the two liquid phases. The logarithm of the ratio of
the concentrations of the un-ionizedsolute in the solvents is called log P: When
one of the solvents is water and the other is a non-polar solvent, then the log P
value is also known as a measure of lipophilicity.
The partition between organic and aqueous buffer can be described by a ‘true’
partition coefficient, Pc, as

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Pc=
[𝐻𝐴−𝑂𝑟𝑔𝑎𝑛𝑖𝑐]
𝐻𝐴−𝐴𝑞𝑢𝑒𝑜𝑢𝑠
or [HA-Organic] =Pc [HA-aqueous] 6
In laboratory an apparent partition coefficient pc” is measured which will vary
with PH or [H+]. This apparent partition coefficient is given by:
PC’=
[𝐻𝐴−𝑂𝑅𝐺𝐴𝑁𝐼𝐶]
[𝐻𝐴]+[𝐴−]
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Substituting for [HA-organic] value from equation 6 and [A-] FOR
EQUATION GIVEN
Pc’ =
[Pc][HA]
[1+
𝐾𝑎
𝐻
+][𝐻𝐴]
Pc’=
𝑝𝑐
[1+
𝐾𝑎
𝐻
+]
This given in an equation with Pc” as function of [H+] with two unknown
parameter, Pc and Ka .This can be converted into a straight line equation by
taking the reciprocal of both sides of the equation.
Thus,
1
𝑃𝑐
=
[𝐻+]
𝑃𝑐[𝐻+]
+
𝑘𝐴
𝑃𝐶[𝐻+]
1
𝑃𝑐′
=
1
𝑃𝑐
+
𝑘𝐴
𝑃𝐶[𝐻+]
PROCEDURE
1. Prepare 100ml of buffer at PH 2.5
2. Weigh accurately 200mg of salicylic acid and transfer to 100ml
volumetric flask and adjust volume by buffer of pH 2.5.similarly prepare
0.02% solution of salicylic acid with buffer of pH3 and 4
3. Take 4ml of buffer pH of 2.5 containing salicylic acid stock solution and
add 1ml of ferric nitrate solution. Allow the colour to form and measure
the absorbance at 540nm using spectrophotometer. This is the
absorbance of absorbance I

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4. Next test 5ml of buffer pH2.5 containing salicylic acid stock solution and
add 5ml of aqueous solvent hexane/ethyl acetate stopper and shake the
test tube for 5 min to complete the extraction.
5. Allow the two phase to settle
6. Remove 4ml of aqueous phase add 1ml ferric nitrate solution(0.55%ferric
nitrate in 0.4m nitric acid)allow the color to form and measure the
absorbance at 540 nm. This is absorbance II
7. Using the two absorbance reading ,calculate the apparent partition
coefficient
𝑃𝑐′
𝑡𝑜𝑡𝑎𝑙 𝑖𝑛 𝑜𝑟𝑔𝑎𝑛𝑖𝑐 𝑝ℎ𝑎𝑠𝑒
𝑡𝑜𝑡𝑎𝑙 𝑖𝑛 𝑎𝑞𝑢𝑒𝑜𝑢𝑠 𝑝ℎ𝑎𝑠𝑒
Where [total in organic] =first absorbance-second absorbance
[Total in organic phase]=Second absorbance
Pc”=
[(𝐴𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒−𝐼)−(𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒−𝐼𝐼)]
𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒 𝐼
8. Repeat the experiment with buffer of PH 3 and 4.
9. Plot 1/pc” versus 1/ [H+] and calculate Pc, Ka, &Pka.
10.Calculate H+ ion concentration with help of equation pH= log 10[H+]
REPORT
Extraction of salicylic acid in organic layer at pH 2.5 was
The partition coefficient of salicylic acid was found to be
Pka of salicylic acid was found to be
REFERENCE
Dr.S.B. Bhise, Dr.R.J.Dias laboratory manual of Biopharmaceutics and
pharmacokinetics

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EXP.NO:4
DATE
DETERMINATION OF PARTITION COEFFICIENT AND
DISSOCIATION CONSTANT OF IBUPROFEN
AIM
To determine Ka, pka, and partition coefficient (Pc) of ibuprofen and study their
relation ship
REQUIREMENTS
Separating funnel, 10ml standard flask, u.v spectrophotometer
THEORY
PH- partition hypothesis was put forth by Brodie et al., which states that drugs
are absorbed from the gastrointestinal track by passive diffusion depending on
the fraction of undissociated drug at the pH of the intestine. Thus, the process of
absorption is governed by:
1. The dissociation constant(pKa) of the drug
2. The lipid solubility of the unionized drug(PC)&
3. The pH at the absorption site
Drug pKa and gastro intestinal pH
PKa is a measure of the strength of an acid or a base. PKa is defined as the
negative logarithm of the equilibrium coefficient of the neutral and charged
forms of a compound. Calculation of pKa allows the proportion of neutral and
charged species at any pH to be estimated, as well as the basic or acidic
properties of the compounds to be defined.
Lower the pKa of an acidic drug, stronger is the acid i.e, greater the proportion
of ionized form at a particular pH. Higher the pKa of a basic drug, the stronger

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is the base. Thus, from the knowledge of pKa of drug and pH at the absorption
site, the relative amount of ionized and unionized drug in solution at a particular
pH and the percent of drug ionized at this pH can be determined by Henderson-
hessalbalch equation.
For weak acids,
PH=pKa +log
𝑖𝑜𝑛𝑖𝑠𝑒𝑑 𝑑𝑟𝑢𝑔 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛
𝑢𝑛𝑖𝑜𝑛𝑖𝑠𝑒𝑑 𝑑𝑟𝑢𝑔 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛
Percentage of drug ionized =
10𝑝𝐻−𝑝𝐾𝑎
1+10𝑝𝐻−𝑝𝐾𝑎
∗ 100
For weak bases,
PH=pKa +log
𝑢𝑛𝑖𝑜𝑛𝑖𝑠𝑒𝑑 𝑑𝑟𝑢𝑔 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛
𝑖𝑜𝑛𝑖𝑠𝑒𝑑 𝑑𝑟𝑢𝑔 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛
Percentage of drug ionized =
10𝑝𝐾𝑎−𝑝𝐻
1+10𝑝𝐾𝑎−𝑝𝐻
∗ 100
LIPOPHILICITY AND DRUG ABSORPTION
Partition coefficient of a drug is a measure of how well a substance partitions
between a lipid (oil) and water. It is defined as the ratio of concentration of
compound in aqueous phase to the concentration in an immiscible solvent, as
the neutral molecule.
Partition coefficient, PC= [concentration in organic phase/ concentration in
aqueous phase]
If the drug exists predominantly in the unionized form, it will be poorly
absorbed if it has poor lipid solubility. Ideally, for optimum absorption, a drug
should have sufficient aqueous solubility to dissolve in the fluids at the
absorption site and lipid solubility high enough to facilitate partitioning of the
drug in the lipoidal biomembrane and into systemic circulation.
The lipid solubility of a drug is determined from its oil/water PC value.PC is a
measure of the degree of distribution of drug between one of the several
organic, waterimmiscible, lipophilic solvent such as n-octanol,chloroform,n-
heptane,etc. and aqueous phase(water or suitable buffer). In general, the

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octanol/PH7.4 buffer partition coefficient value in the range of 1-2 of a drug is
sufficient to predict passive absorption across lipoidal membranes
PROCEDURE
1. Prepare 100ml of buffer at pH2.5
2. Weigh accurately 20mg of ibuprofen and transfer to 100ml volumetric
flask and adjust volume by buffer pH 2.5. Similarly prepare 0.02%
solution of ibuprofen with buffer of pH 3&4.
3. Take 4ml of buffer pH of 2.5 containing ibuprofen solution.measure the
absorbance at 540nm using spectrophotometer. This is taken as
absorbance I
4. Next, take 5ml of buffer pH2.5 containing ibuprofen solution and add
5ml of aqueous solvent hexane/ ethyl acetate. Stopper and shake the test
tube for 5min to complete the extraction. Allow the two phase to settle.
Remove 4ml of aqueous phase and measure the absorbance at 540nm.
This is absorbanceII
11. Using the two absorbance reading ,calculate the apparent partition
coefficient
𝑃𝑐′
𝑡𝑜𝑡𝑎𝑙 𝑖𝑛 𝑜𝑟𝑔𝑎𝑛𝑖𝑐 𝑝ℎ𝑎𝑠𝑒
𝑡𝑜𝑡𝑎𝑙 𝑖𝑛 𝑎𝑞𝑢𝑒𝑜𝑢𝑠 𝑝ℎ𝑎𝑠𝑒
Where [total in organic] =first absorbance-second absorbance
[Total in organic phase]=Second absorbance
Pc”=
[(𝐴𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒−𝐼)−(𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒−𝐼𝐼)]
𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒 𝐼
12.Repeat the experiment with buffer of PH 3 and 4.
13.Plot 1/pc” versus 1/ [H+] and calculate Pc, Ka, &Pka.
14.Calculate H+ ion concentration with help of equation pH= log 10[H+]

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REPORT
Extraction of ibuprofen inorganic layer at pH2.5 was
Partition coefficient of ibuprofen was
PKa value of ibuprofen
REFERENCE
Dr.S.B. Bhise, Dr.R.J.Dias laboratory manual of Biopharmaceutics and
pharmacokinetics page no1-6

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EXP.NO:5
DATE:
PROTEIN BINDING STUDY USING DYNAMIC DIALYSIS METHOD
AIM
Study the protein binding of ibuprofen by dynamic dilution method.
REQUIREMENTS
Ibuprofen, egg albumin, egg membrane, u.v spectrophotometer, magnetic stirrer
etc.
THEORY
The phenomenon of complex formation with proteins is called as protein
binding of a drug. Binding of drugs generally involves weak chemical bonds
such as hydrogen bonds, ionic bonds or Vander waal’sforces and therefore is as
reversible process.
Binding of a drug to protein contained in the body influence their action in a
number of ways:
1. Protein may facilitate the distribution of a drug throughout the body
2. It may inactivate the drug by not enabling a sufficient concentration of
free drug to develop at the receptor site.
3. It may retard excretion of a drug
4. The interaction of a drug with protein may cause
a) The displacement of body hormones or a co administered agent
b) A configurationally change in the protein
c) Formation of a drug protein complex that itself is biological active.

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Number of methods are available for studying protein binding of
drugs.equilibrium dialysis, dynamic dialysis, ultra filtration and electrophoresis
are the classic techniques widely used to study protein binding.
Before reaches to the receptor site the drug molecule may react with protein
present in biological system like plasma protein, eg: albumin, globulin etc.
Binding of drug to protein the body influencing a number of ways protein
binding facilitates the distribution of drug throughout the body. In activating the
drug by not providing sufficient drug concentration at the site of action in this
method are placed in the egg membrane tube as a result drug protein binding
complex will be developed. This complex or macro molecules can’t pass
through outside vessel containing drug solution. Only unbounded or free drug
permits through membrane free drug concentration is measured using U.V
spectrophotometric method and the percentage of protein
Percentage protein binding =
𝑡𝑒𝑠𝑡 𝑠𝑎𝑚𝑝𝑙𝑒
𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑠𝑎𝑚𝑝𝑙𝑒
PROCEDURE
Preparation of egg shell membrane
Soak a whole chicken egg in 0.5N HCl solution. The outer calcaraceous shell
gets dissolved then cut off part of egg shell membrane and remove the inner
contents. Wash the obtained membrane thoroughly in distilled water and store
in refrigerator.
Protein binding study of ibuprofen
 Tie the egg membrane at one end of open ended glass cylinder and use it
as protein compartment[donor]
 Use glass beaker capacity of 25ml as non-protein compartment receptor
and fill it with 20ml distilled water.

17
 Place the drug solution to the inner solution tube an immerse into the
beaker. Take care to maintain the level of drug solution coincide with
buffer in outside compartment and fixed with stand.
 Keep this whole setup on magnetic stirrer and sir the outer compartment
continuously at an optimal speed. Maintain the temperature 350
c ±20
c for
the whole experiment.
 At predetermined time intervals remove 1ml of the sample from the
beaker an replace it with same volume of 6.8 phosphate buffer.
 Determine the concentration of ibuprofen spectrophotometrically at
254nm.
REPORT
Percentage of protein binding of given drug ibuprofen was found to be
REFERENCE
Dr.S.B.Bhise, Dr.R.J. Dias laboratory manual of Biopharmaceutics and
pharmacokinetics

18
EXP.NO:6
DATE:
DETERMINATION OF PROTEIN BINDING USING EQUILIBRIUM
DIALYSIS METHOD
AIM
To determine the protein binding efficiency of ibuprofen.
REQUIREMENTS
Egg membrane, open ended cylinder, beaker, magnetic stirrer, and ibuprofen.
THEORY
In this method human serum albumin is placed in egg membrane tube and the
drug is placed in the outside vessel which is having Ph 6.8 phosphate buffer
solution.As its dialysis continues the drug molecule permeate through the
membrane and enter into egg membrane tube.As a result drug protein binding
is observed.Albumin being macromolecules can’t pass through the membrane to
outside the vessel.As the time elapses more amount of drug permeate and
available in the tube.If binding occurs the drug concentration in the bag
containing protein should be greater than its concentration in outside vessel.
PROCEDURE
 Take an open ended cylinder and the one end is tied using egg
membrane.
 Prepare 5% albumin solution and this solution was introduced [5ml into
egg membrane containing cylinder].
 The cylinder is immersed into the beaker containing buffer solution with
Ph6.8.
 The whole setting is placed on the magnetic stirrer.

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 5ml sample withdrawn from beaker and replaced with fresh pH 6.8
phosphate buffer.
 The withdrawn samples are analysed suitably at 254nm.
 The percentage of protein binding can be calculated by the formula:
Percentage protein binding =
𝑡𝑒𝑠𝑡 𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒
𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒
REPORT
Percentage of protein binding of ibuprofen at the end of 30min was found to be
REFERENCE
Dr.S.B.Bhise, Dr.R.J. Dias laboratory manual of Biopharmaceutics and
pharmacokinetics

20
EXP.NO:7
DATE:
DESIGN AND EVALUATION OF TRANSDERMAL PATCHES
CONTAINING DICLOFENAC SODIUM
AIM
To prepare and evaluate transdermal patches containing diclofenac sodium and
evaluate their properties.
REQUIREMENTS
Diclofenac sodium, ethyl cellulose, HPMC, polyvinyl alcohol, propylene
glycol, methanol.
THEORY
Transdermal therapeutic systems are defined as self-contained discret dosage
forms which when applied to the intact skin, deliver the drugs through skin for a
controlled rate to systemic circulation.Transdermal drug delivery systems are
topically administered medicaments in form of patches that deliver drugs for
systemic effects at a predetermined and controlled rate. Transdermal drug
delivery is the noninvasive delivery of medications from surface of skin. Drugs
can be delivered across the tissue adjacent to the site of application [topical
delivary] or to skin to have an effect after distribution to circulatory system,
inorder to deliver therapeutic agents through human skin for systemic effects.
The comprehensive morphological biophysical and physiochemical properties
of skin are to be considered. Transdermal drugs provides a leadin edge over
injectables and oral routes by increasing patient compliance and avoiding first
pass metabolism respectively. Transdermal drug delivery not only provides
controlled, constant administration of drug but also allows continous input of

21
drug with short biological halflife and eliminates pulsed entry into systemic
circulation. It often causes undesirable side effect.
PROCEDURE
Solvent evaporatory method
 Polymer of different ratio are accurately weighed and dissolved in 5ml of
methanol
 In this solution add 1.5ml of propylene glycol [plastiscer]
 After preparation of polymeric solution 10mg of dichlofenac sodium is
dispersed using magnetic stirrer for 2hrs
 The preparation is done on PVA backing membrane and dried at 400
c for
4hrs
 Finally this patches was removed and wrap with aluminium foil and kept
in dessicator
Preparation of polyvinyl alcohol
 5% solution of PVA was prepared and mixed thoroughly using
magnetic stirrer
 A thick solution is obtained the solution is poured on glass mould
lined with aluminium foil and the solution is dried at 400
c in an oven.
Evaluation of transdermal patches
 Thickness of thin film is determined by screw guage apparatus.
 Folding endurance
Folding the patches at same point, a number of times to blocked
is noted
 Surface pH. of patches
Invitro permeability study using of Franz diffusion cell

22
REPORT
Transdermal patches was prepared and evaluated
REFERENCES

23
EXP.NO:8
DATE:
FORMULATION AND EVALUATION OF TRANSDERMAL PATCHES
OF IBUPROFEN
AIM
To formulate and evaluate transdermal patches of ibuprofen.
REQUIREMENTS
Ethyl acetate, methanol, ethyl cellulose, dibutyl phthalate, ibuprofen.
THEORY
Transdermal patches drug delivery system administered topically in the form of
patches that deliver the drug for a predetermined and controlled rate.
Components of transdermal drug delivery system include drug, polymer,
plastisizer, penetration enhancer, backing membrane.It is very helpful for the
avoidance of first pass metabolism for long duration of action of drugs and also
suitable for drugs having very short half-life. Narrow therapeutic index, poor
oral bioavailability. The drugs used in transdermal drug delivery system should
have:
 Water solubility greater than 1µg/ml.
 Oil solubility greater than 1µg/ml.
 Molecular weight less than 1000.
 Dose less than 10mg.
Transdermal drug delivery system can be classified into two categories:
 Rate programmed transdermal drug delivery system.
 Physical stimuli activated transdermal drug delivery system.

24
Here, molding technique was used to prepare the drug free patches of ethyl
cellulose. The required quantity of polymer was added to casting solution until
uniform solution is attained.Dibutyl phthalate was added as a plastisizer.The
prepared patch can be evaluated by using Franz diffusion cell having surface
area of about 3.14cm2.
PROCEDURE
 Weigh separately 400mg ethyl cellulose and 100mg ibuprofen.
 Take 100ml beaker and add 16ml ethyl acetate and 4ml methanol in
ratio 8:2.
 Keep the beaker on top of magnetic stirrer and add slowly ethyl
cellulose to form complete dispersion.
 To this add 100mg drug and again stir to get a uniform solution.
 Finally add required quantity of butyl phthalate, pour the solution to
petridish having area 9.4cm2
.
 Put a funnel in an inverted position inorder to give controlled
evaporation.
 After 24hrs scrap the film and do the evaluation study using Franz
diffusion study.
EVALUATION OF PREPARED TRANSDERMAL PATCHES
Mount the cellophane membrane on the neck of the diffusion cell. Fill the
receptor compartment completely filled with buffer. Transdermal patch was
taken slightly soaked with buffer place above the cellophane membrane. Place
the assembly on a magnetic stirrer with thermostat at 370
c±50
c.Withdraw 1ml of
solution at specified time intervals and replace with same quantity of buffer.
Determine the absorbance of diluted samples at 290nm.

25
REPORT
Transdermal patches of ibuprofen was prepared and submitted.
REFERENCES

26
EXP.NO:9
DATE:
MODELLING OF DRUG RELEASE FROM DELIVERY SYSTEM
USING KINETICS SOFTWARE
AIM
To determine the release pattern and release mechanisms of given invitro
release data.
REQUIREMENTS
Kinetics software, dissolution data.
THEORY
Invitro release kinetics
The results of invitro release profile obtain from the formulation could be
plotted in models of data treatment as follows:
1. Zero order kinetics model –cumulative percentage drug release Vs. time
2. First order kinetics model-log cumulative percent drug remaining Vs. time.
3. Higuchi’s model-cumulative % drug released Vs. square root of time.
4. Korsemeyer equation or Peppa’s model-cumulative %drug released Vs log
time.
Zero order kinetics
Zero order release would be predicted by following equation:
At=A0-K0t
Where,At=drug release at time t.
A0=initial drug concentration
K0 =zero order rate constant.

27
When the data plotted as cumulative percent drug release Vs time ,if the plot is
linear ,then the data obeys zero order kinetics and its slope is equal to zero order
release constant.
First order kinetics
First order released predicted by following equation:
LogC =logC0-
𝑘𝑡
2.303
Where, C=amount of drug remained at time t
C0=initial amount of drug
K=first order rate constant
When data plotted as log cumulative %drug remaining Vs time yields a straight
line indicating that release follow first order kinetics.The constant k1 can be
obtained by multiplying 2.303 with slope value.
Higuchi’s model
Drug released from matrix devices by diffusion has been described by
Higuchi’s diffusion equation:
Q = [D𝜀/𝜏(2𝐴 − 𝜀𝐶S) CSt]1/2
Where, Q =amount of drug released at time t
D = diffusion coefficient of drug in matrix.
CS = solubility of drug in matrix.
𝜀 = porosity of matrix
𝜏 = tortocity
T = time in hours at which amount of drug is released.
Above equation may be simplified if one assumes D,CS, A are constant ,then
equation becomes,
Q=kt1/2

28
When the data is plotted according to equation i.e,cumulative drug release Vs
square root of time yields a straight line indicating that drug was released by
diffusion mechanism,then slope is equal to k.
Korsemeyer equation or Peppa’s method
To study mechanism of drug release from controlled release multiparticles of
drug the released data were also fitted to the well known exponential
equation.ie, which is often used to describe the drug release behavior from
polymeric systems.
Mt//Ma =ktn
Mt//Ma=fraction of drug released at time t
k=constant incorporating structural and geometrical characteristics of drug or
polymer system.
n=diffusion exponent related to mechanism of release.
Above equation can be simplified by applying log on both sides,
𝑙𝑜𝑔
𝑀𝑡
𝑀𝑎
=log K+ n Log t
REPORT
The given formulation was sustained release and obeys first order and zero
order kinetics. The mechanism is Fickian diffusion.
REFERENCE
Indian journal of pharmaceutical sciences

29
EXP.NO:10
DATE:
DETERMINATION OF RELEASE FOR KINETICS FOR THE
DISSOLUTION DATA
AIM
To determine the invitro release kinetics profiled of given data using release
kinetics software.
REQUIREMENTS
Kinetics software,dissolution data.
THEORY
Invitro release kinetics
The results of invitro release profile obtain from the formulation could be
plotted in models of data treatment as follows:
1. Zero order kinetics model –cumulative percentage drug release Vs time
2. First order kinetics model-log cumulative percent drug remaining Vs time.
3. Higuchi’s model-cumulative % drug released Vs square root of time.
4. Korsemeyer equation or Peppa’s model-cumulative %drug released Vs log
time.
Zero order kinetics
Zero order release would be predicted by following equation:
At=A0-K0t
Where,At=drug release at time t.
A0=initial drug concentration
K0 =zero order rate constant.

30
When the data plotted as cumulative percent drug release Vs time ,if the plot is
linear ,then the data obeys zero order kinetics and its slope is equal to zero order
release constant.
First order kinetics
First order released predicted by following equation:
LogC =logC0-
𝑘𝑡
2.303
Where, C=amount of drug remained at time t
C0=initial amount of drug
K=first order rate constant
When data plotted as log cumulative %drug remaining Vs time yields a straight
line indicating that release follow first order kinetics.The constant k1 can be
obtained by multiplying 2.303 with slope value.
Higuchi’s model
Drug released from matrix devices by diffusion has been described by
Higuchi’s diffusion equation:
Q = [D𝜀/𝜏(2𝐴 − 𝜀𝐶S)CSt]1/2
Where, Q =amount of drug released at time t
D = diffusion coefficient of drug in matrix.
CS = solubility of drug in matrix.
𝜀 = porosity of matrix
𝜏 = tortocity
T = time in hours at which amount of drug is released.
Above equation may be simplified if one assumes D,CS,A are constant ,then
equation becomes,
Q=kt1/2

31
When the data is plotted according to equation i.e,cumulative drug release Vs
square root of time yields a straight line indicating that drug was released by
diffusion mechanism,then slope is equal to k.
Korsemeyer equation or Peppa’s method
To study mechanism of drug release from controlled release multiparticles of
drug the released data were also fitted to the well known exponential
equation.ie, which is often used to describe the drug release behavior from
polymeric systems.
Mt//Ma =ktn
Mt//Ma=fraction of drug released at time t
k=constant incorporating structural and geometrical characteristics of drug or
polymer system.
n=diffusion exponent related to mechanism of release.
Above equation can be simplified by applying log on both sides,
𝑙𝑜𝑔
𝑀𝑡
𝑀𝑎
=log K+ n Log t
REPORT
The given formulation was found to be controlled release and obeys zero order
kinetics. The mechanism is super case II transport.
REFERENCE
Indian journal of pharmaceutical sciences

32
EXP.NO:11
DATE:
ABSORPTION STUDY FOR DICLOFENAC SODIUM
AIM
To carry out absorption study for diclofenac sodium.
REQUIREMENTS
Chicken ileum, beaker, buffer, drug solution (diclofenac sodium)
THEORY
Absorption is a process of movement of unchanged drug from the site of
administration to systemic circulation. Absorption study should be carried out
by exvivo method in vivo method insitu method. Exvivo method is simple and
produced reproducible value.
Drug to be absorbed by various mechanism such as passive, active, facilitated
diffusion etc. so most of the absorption takes place by passive diffusion process.
It means movement of drug from higher concentration to lower concentration.
In the body most of the absorption took place in small intestine because villi,
microvilli is present in the small intestine and also have wide range of pH from
4.5-7.2(average pH 6.8) the intestine juice also contains certain enzymes. These
enzymes encouraged the absorption by carrier mediated transport. Hence
chicken ileum was taken for the absorption study.
PROCEDURE
The small segment of chicken ileum (6cm long) was removed. One end of the
ileum tube was tied, filled with buffer solution and the other end of the opening
was tied with thread. The step up was immersed in the diclofenac sodium

33
solution (100mg/100ml) and the samples were withdrawn from flask at
appropriate intervals and analyzed the drug content by UV method at 268nm.
FORMULA
Amount of drug absorbed =
𝑡𝑒𝑠𝑡 𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒×𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛
𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑎𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒×𝑡𝑒𝑠𝑡 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛
REPORT
 The absorption study of diclofenac sodium by everted sac technique was
performed.
 The percentage drug absorbed was found to be
REFERENCES
S.P.Vyas, R.K.Khar, “Targeted and Controlled drug delivery”, novel carrier
system, CBS publishers and distributors, New Delhi, page no: 122

34
EXP.NO:12
DATE:
DETERMINATION OF DIFFUSION RATE AND PERMEABILITY CO-
EFFICIENT OF DICLOFENAC SODIUM USING DIFFUSION CELL
AIM
To determine the diffusion rate and permeability coefficient of diclofenac
sodium using cellophane membrane or semipermeable membrane.
REQUIREMENTS
Diclofenac sodium, coloring reagent, cellophane membrane, open diffusion
cell, burette stand, beaker, glass rod etc.
THEORY
Stratum corneum is the principle barrier for cutaneous penetration allowing
slow absorption for majority of drugs. In any case, the permeability of stratum
corneum is increased by using appropriate vehicle. The best vehicle for topical
use has been described as the one which contribute to reversible decrease in the
stratum corneum resistance and allows diffusion of molecules into the vehicle
itself.
The most common invitro design is one where a membrane separates two
compartments-one compartment contains the drug in a vehicle, possibly a single
aqueous or buffer solution and the other compartment contains a receptor
(receives). Solution that provides sink condition after sufficient time, steady
state permeation across the membrane is constant under this condition following
equation can be used.
𝑑𝑚
𝑑𝑡
=
𝐷𝐶𝑜
ℎ
-(1)

35
Where m = cumulative mass of the drug that passes through per unit area of the
membrane in time t
Co = concentration of the drug in the first layer of membrane
h = membrane thickness
In practical terms it is very difficult to measure Co, concentration of drug in
first layer of the membrane, removal of the outer layer for assay is problematic
and contamination from the applied donor solution is almost inevitable.
However concentration of the drug in the vehicle bathing the stain membrane
and is usually known or can be determined relatively easily. Since Co and Cv are
simply related.
P =
𝐶𝑜
𝐶𝑣
so, Co = PCv (2)
P = partition coefficient of drug between the membrane and the vehicle.
𝑑𝑚
𝑑𝑡
=
𝐷𝑃𝐶𝑣
ℎ
(3)
This is more widely applied equation in examining transdermal drug delivery
data. A plot of m1 cumulative amount of drug passing through a membrane can
be defined by equation.
Kp =
𝐷𝑝
ℎ
(4)
Substituted in equation (3)
𝑑𝑚
𝑑𝑡
= Jss = KpCv (5)
The steady state flux (Jss) is simply obtained as the gradient of the linear
portion of the permeation profile and if concentration of drug in the applied
vehicle is known. Then the permeability coefficient can be determined. Higher
the value of Kp and Jss obtained for the formulation higher will be the
permeation.
PREPARATION OF PHOSPHATE BUFFER pH 7.4
Dissolved required quantity of KH2PO4 and NaOH in distilled water to
produce 1000ml. Adjust the pH 7.4

36
INVITRO DIFFUSION STUDY USING OPEN DIFFUSION CELL
Cellophane membrane was prepared and it is tied to one end of open tube.
50ml of receptor solution in a beaker was taken.
5ml of sample was taken in the open tube and immersed in the receptor
compartment.
Periodically at 0, 15, 30, 45, 60 min 1ml of sample was taken and replaced with
fresh medium.
Measured the absorbance at 268nm by UV spectrophotometrically.
The graph was plotted and flux of permeability coefficient was determined.
REPORT
The flux was found to be
The permeability co-efficient of diclofenac sodium was found to be
REFERENCE
Laboratory manual of Biopharmaceutics &pharmacokinetics by V.B Phase
,R.J.Duas page no:18-21

37
EXP.NO:13
DATE:
DETERMINATION OF PERMEABILITY COEFFICIENT AND
DIFFUSION RATE OF PARACETAMOL USING DIFFUSION CELL
AIM
To report the permeability coefficient and diffusion rate of paracetamol using
cellophane.
REQUIREMENTS
Paracetamol, cellophane membrane, open diffusion cell, burette stand,
beaker, glass rod etc.
THEORY
Stratum corneum is the principle barrier for cutaneous penetration allowing
slow absorption for majority of drugs. In any case, the permeability of stratum
corneum is increased by using appropriate vehicle. The best vehicle for topical
use has been described as the one which contribute to reversible decrease in the
stratum corneum resistance and allows diffusion of molecules into the vehicle
itself.
The most common invitro design is one where a membrane separates two
compartments-one compartment contains the drug in a vehicle, possibly a single
aqueous or buffer solution and the other compartment contains a receptor
(receives). Solution that provides sink condition after sufficient time, steady
state permeation across the membrane is constant under this condition following
equation can be used.
𝑑𝑚
𝑑𝑡
=
𝐷𝐶𝑜
ℎ
-(1)

38
Where m = cumulative mass of the drug that passes through per unit area of the
membrane in time t
Co = concentration of the drug in the first layer of membrane
h = membrane thickness
In practical terms it is very difficult to measure Co, concentration of drug in
first layer of the membrane, removal of the outer layer for assay is problematic
and contamination from the applied donor solution is almost inevitable.
However concentration of the drug in the vehicle bathing the stain membrane
and is usually known or can be determined relatively easily. Since Co and Cv are
simply related.
P =
𝐶𝑜
𝐶𝑣
so, Co = PCv (2)
P = partition coefficient of drug between the membrane and the vehicle.
𝑑𝑚
𝑑𝑡
=
𝐷𝑃𝐶𝑣
ℎ
(3)
This is more widely applied equation in examining transdermal drug delivery
data. A plot of m1 cumulative amount of drug passing through a membrane can
be defined by equation.
Kp =
𝐷𝑝
ℎ
(4)
Substituted in equation (3)
𝑑𝑚
𝑑𝑡
= Jss = KpCv (5)
The steady state flux (Jss) is simply obtained as the gradient of the linear
portion of the permeation profile and if concentration of drug in the applied
vehicle is known. Then the permeability coefficient can be determined. Higher
the value of Kp and Jss obtained for the formulation higher will be the
permeation.
PREPARATION OF PHOSPHATE BUFFER pH 7.4
Dissolved required quantity of KH2PO4 and NaOH in distilled water to
produce 1000ml. Adjust the pH 7.4

39
INVITRO DIFFUSION STUDY USING OPEN DIFFUSION CELL
Cellophane membrane was prepared and it is tied to one end of open tube.
50ml of receptor solution in a beaker was taken.
5ml of sample was taken in the open tube and immersed in the receptor
compartment.
Periodically at 0, 15, 30, 45, 60 min 1ml of sample was taken and replaced with
fresh medium.
Measured the absorbance at 257nm by UV spectrophotometrically.
The graph was plotted and flux of permeability coefficient was determined.
REPORT
The flux was found to be
The permeability co-efficient of paracetamol was found to be
REFERENCE
Laboratory manual of Biopharmaceutics &pharmacokinetics by V.B Phase
,R.J.Duas page no:18-21

40
EXP.NO:14
DATE:
DETERMINATION OF PHARMACOKINETIC PARAMETERS-1
AIM
To determine the following pharmacokinetic parameter of drug (Cmax, tmax,
AUC (0-α), Ke, t1/2, which is administered orally (500mg)
THEORY
Pharmacokinetics is the study of the time course of absorption, distribution,
biotransformation, and excretion of drugs.
Pharmacokinetic Parameters
The predictive capability of a pharmacokinetic model lies in the proper
selection and development of mathematical functions called parameters that
govern a pharmacokinetic process. In practice pharmacokinetic parameters are
determined experimentally from a set of drug concentrations collected over
various times known as data. Parameters are also called as variables. Variables
are of two types.
Independent variables which are not affected by any other parameter, for
example time.
Dependent variables which change as the independent variables change, for
example, plasma drug concentration
Certain points, which are important to note regarding application of parameters
in pharmacokinetic studies, include-
 The number of parameters needed to describe the pharmacokinetic model
depends upon the complexity of the pharmacokinetic process and on the
route of drug administration.
 More the number of parameters more are the difficulties in accurate
estimation of these parameters.

41
 For the pharmacokinetic parameters to be valid, the number of data points
should always exceed the number of parameters in the pharmacokinetic
model.
DATA:
TIME (hrs.) Plasma drug concentration(µg)
0 0
0.5 5.4
1 10
2 17.2
4 25.8
8 29.8
12 26.6
18 19.4
24 13.3
36 5.9
48 2.6
REPORT
Cmax =
tmax =
AUC (0-α) =
Ke =
t1/2 =
REFERENCES
 Textbook of Biopharmaceutics and Pharmacokinetics by D.M.
Brahmankar, Sunil.B.Jaiswal
 Textbook of Biopharmaceutics and Pharmacokinetics by Dr.Javed Ali,
Dr. Alka Ahuja, Dr. Sanjula Baboota, Dr.Roop.K.Khar

42
EXP.NO:15
DATE:
DETERMINATION OF PHARMACOKINETIC PARAMETERS-II
AIM
To determine the following pharmacokinetic parameters
Peak plasma concentration Cmax
Time of peak concentration tmax
Elimination rate constant Ke
Biological half-life (t1/2)
Area under curve AUC (0-α)
Area under first moment curve AUMC (0-α)
THEORY
Pharmacokinetics is the study of the time course of absorption, distribution,
biotransformation, and excretion of drugs.
Pharmacokinetic Parameters
The predictive capability of a pharmacokinetic model lies in the proper
selection and development of mathematical functions called parameters that
govern a pharmacokinetic process. In practice pharmacokinetic parameters are
determined experimentally from a set of drug concentrations collected over
various times known as data. Parameters are also called as variables. Variables
are of two types.
Independent variables which are not affected by any other parameter, for
example time.
Dependent variables which change as the independent variables change, for
example, plasma drug concentration
Certain points, which are important to note regarding application of parameters
in pharmacokinetic studies, include-

43
 The number of parameters needed to describe the pharmacokinetic model
depends upon the complexity of the pharmacokinetic process and on the
route of drug administration.
 More the number of parameters more are the difficulties in accurate
estimation of these parameters.
 For the pharmacokinetic parameters to be valid, the number of data points
should always exceed the number of parameters in the pharmacokinetic
model.
DATA:
TIME (hrs.) Plasma drug concentration(µg)
1 3.3
2 6.8
3 8.8
4 9.1
5 9.9
6 14.3
7 11.3
8 1.9
9 0.9
REPORT
Cmax =
tmax =
AUC (0-α) =
AUMC (0-α) =
MRT
Ke =
t1/2 =

44
REFERENCES

45
EXP.NO:16
DATE:
DETERMINATION OF PHARMACOKINETIC PARAMETERS
INTRAVENOUS BOLUS –ONE COMPARTMENT OPEN MODEL
AIM
To determine the pharmacokinetic parameters (Ke, t (1/2), Vd, AUC, clearance)
THEORY
One compartment open pharmacokinetic model depicts the body as a single
kinetically homogenous unit that has no barrier to the movement of drug. Also,
the final distribution equilibrium between the drug in plasma and other body
fluids is attained instantaneously and maintained at all time. This model applies
only to those drugs that distributes rapidly.
The plasma drug concentration is representative of all body tissues
concentration. The term open indicates the input and output are unidirectional.
Intravenous bolus administration
When a drug that distributes rapidly in the body is given in the form of rapid IV
bolus or slug, it takes about 1-3 minutes for complete circulation, therefore the
absorption rate is not considered in calculation.
Following intravenous bolus administration of a drug, by considering following
assumptions the fundamental pharmacokinetic parameters of a drug can be
obtained.
 One compartment model, first order process and passive diffusion are
operative
 No metabolism takes place(elimination is 100% via renal excretion)
 The drug is being monitored in blood (plasma /serum) and urine.

46
Important Pharmacokinetic parameters
1. Elimination rate constant Ke
2. Elimination half-life (t1/2)
3. Apparent Volume of Distribution (Vd)
4. Clearance (Clt)
5. Total area under curve(AUC)
6. Calculation of K from urinary excretion data
DATA
The plasma drug concentration time profile, after IV administration of an
antibiotic (250mg) is given below. Plot the data and describe the model.
Time(hr.) Plasma drug concentration(µg/ml)
1 8
2 6.3
3 4.9
4 4
5 3.2
6 2.5
7 1.9
REPORT
AUC (0-α) graphically =
AUC (0-α) theoretically =
Volume of distribution (Vd) =
Elimination rate constant =

47
REFERENCES
 Laboratory Manual of Biopharmaceutics and Pharmacokinetics by
Dr.S.B.Bhise, Dr.R.J. Dias, Dr. S.C Dhawale, Shri. K. K. Mali

48
EXP.NO:17
DATE:
DETERMINATION OF PHARMACOKINETIC PARAMETERS IV
BOLUS ONE COMPARTMENT OPEN MODEL- II
AIM
To determine the following pharmacokinetic parameters (Ke, t1/2, Vd, ClT,
AUC(0-α)
THEORY
One compartment open pharmacokinetic model depicts the body as a single
kinetically homogenous unit that has no barrier to the movement of drug. Also,
the final distribution equilibrium between the drug in plasma and other body
fluids is attained instantaneously and maintained at all time. This model applies
only to those drugs that distributes rapidly.
The plasma drug concentration is representative of all body tissues
concentration. The term open indicates the input and output are unidirectional.
Intravenous bolus administration
When a drug that distributes rapidly in the body is given in the form of rapid IV
bolus or slug, it takes about 1-3 minutes for complete circulation, therefore the
absorption rate is not considered in calculation.
Following intravenous bolus administration of a drug, by considering following
assumptions the fundamental pharmacokinetic parameters of a drug can be
obtained.
 One compartment model, first order process and passive diffusion are
operative
 No metabolism takes place(elimination is 100% via renal excretion)
 The drug is being monitored in blood (plasma /serum) and urine.

49
Important Pharmacokinetic parameters
10.Clearance (Clt)
11.Total area under curve(AUC)
12.Calculation of K from urinary excretion data
DATA
The following data shows the plasma concentration profile obtained from I.V
bolus administration of amoxicillin injection 250mg.
0 30
5 22
10 11.2
20 9
30 4.8
40 2.8
50 1.5
60 0.86
REPORT
4. Clearance (Clt)
5. Total area under curve(AUC)

50
REFERENCES

51
EXP.NO:18
DATE:
DETERMINATION OF VARIOUS PHARMACOKINETIC
PARAMETERS AFTER IV INFUSION
AIM
To calculate various pharmacokinetic parameters from the given blood data of
IV infusion (one compartment model)
THEORY
When a single intravenous bolus dose of a drug is given, the desired
therapeutic concentrations is achieved immediately. However this mode of
administration is unsuitable when it is necessary to maintain plasma or tissue
concentrations for prolonged duration. Here the aim is to reach the therapeutic
range and then maintaining drug concentration within the therapeutic range for a
longer duration. It is common practice, in the hospital setting to infuse a drug at
a constant rate (constant rate input or zero order input). This method permits
precise and readily controlled drug administration.
DATA
Estimate the volume of distribution, elimination rate constant, half-life,
clearance from the data in the following table obtained on infusing a drug at the
rate of 50mg/hr for 7.5h
0 0
2 3.4
4 5.4
6 6.5
7.5 7

52
9 4.6
12 2
15 0.9
 Prepare a semi logarithmic plot and estimate the half-life of drug
 Calculate elimination rate constant
 Calculate volume of distribution
 Calculate total clearance
REPORT
4. Clearance (Clt)
REFERENCES

53
EXP.N0:19
DATE
DETERMINATION OF ORDER OF PROCESS,RATE CONSTANT AND
BIOLOGICAL HALF LIFE
AIM
To determine the order, rate constant and half life
DATA
10 96
20 89
40 73
60 57
90 34
120 10
180 2.5
Plot the above data on both on both semi logarithmic graph and standard
rectangular co-ordinate
a) As it decrease in amount of drug , appeared to be zero order or first order
b) What is rate constant
c) Find half life
REPORT
 The standard rectangular graph represent the process is of zero order
 Rate constant (k)
 Half-life(t1/2)
REFERENCE
Applied Biopharmaceutics and Pharmacokinetics by Leon Shargel, Susanna Wu
Pong, Andrew B.C. Yu

54
EXP.NO:20
DATE
DETERMINATION OF ORDER OF PROCESS, RATE CONSTANT,
AND HALF LIFE
AIM
To determine the order, rate constant and half life
DATA
4 70
10 58
20 422
30 31
60 12
90 4.5
120 1.7
Plot the above data on both on both semi logarithmic graph and standard
rectangular co-ordinate
d) As it decrease in amount of drug , appeared to be zero order or first order
e) What is rate constant
f) Find half life
REPORT
 The standard rectangular graph represent the process is of first order
 Rate constant (k)
 Half-life(t1/2)
REFERENCE
Applied Biopharmaceutics and Pharmacokinetics by Leon Shargel, Susanna Wu
Pong, Andrew B.C. Yu

55
EXP.NO:21
DATE
DETERMINATION OF PHARMACOKINETIC PARAMETERS-ONE
COMPARTMENT OPEN MODEL EXTRAVASCULAR
ADMINISTRATION
AIM
To determine the pharmacokinetic parameters
THEORY
Administration of drug dose by an extravascular route involves passage of the
drug by absorption through a biological membrane. The plasma profile obtained
following extravascular administration of a drug is different from plasma profile
of same drug obtained after the drug administered as a rapid intravenous bolus
injection because the entire dose of administered drug is not absorbed all at
once.
DATA
The data given below is obtained from after administration of 500mg
antibiotic orally. Find out the pharmacokinetic parameters Ke, Ka, Cmax, tmax
absorption and elimination t1/2, AUC (o-α), lag time, Vd, assume 100% drug is
absorbed.
1 26.501
2 36.091
3 37.512
4 36.055
5 32.924
6 29.13

56
8 22.784
16 7.571
18 5.734
20 4.343
REPORT
REFERENCES

57
EXP.NO:22
DATE
DETERMINATION OF ABSORPTION RATE CONSTANT BY
METHOD OF RESIDUALS
AIM
To determine absorption half-life and absorption rate constant (Ka) for given
data by using method of residuals
THEORY
Absorption rate constant can be calculated by method of residuals. The
technique is also known as feathering or peeling and stripping. It is commonly
used in pharmacokinetics to resolve a multiexponential curve into its individual
components for drugs that follows one compartment kinetics and are
administered extravascularly.
DATA
0.5 5.36
1 9.35
2 17.18
4 25.78
8 29.78
12 26.63
18 19.40
24 13.26
36 5.88
48 2.56
70 0.49

58
REPORT
REFERENCES

59
EXP.NO:23
DATE
DETERMINATION OF ABSORPTION RATE CONSTANT BY
WAGNER NELSON METHOD
AIM
To calculate absorption rate constant of using Wagner Nelson method
THEORY
After a single oral dose of a drug, at any time the amount of drug absorbed into
the systemic circulation Aa, is the sum of the amount of drug in the body A and
the amount of drug eliminated from the body Ae. Thus
Aa =A+Ae (1)
The amount of drug in the body is A = VC while the amount of drug eliminated
at any time t can be calculated as follows
Ae = KVAUC(0-t) (2)
Substituting the values of A and Ae in equation 1 gives
Aa = VC + KVAUC(0-t) (3)
The total amount of drug absorbed into the systemic circulation from time zero
to infinity Aa
α
can be given as
Aa
α
= VCα
+ KVAUC(0-α) (4)
Since at t= ,C = 0, the above equation can be reduced to
Aa
α
= KVAUC(0-α) (5)
Fraction of drug absorbed at any time t is given as
Aa
Aa
=
VC+ KVAUC(0−α)
KVAUC(0−α)
(6)
Aa
Aa
=
C+ KAUC(0−α)
KAUC(0−α)
(7)
Percent drug unabsorbed at any time is therefore
%ARA = [1-
Aa
Aa
]100 =[
C+ KAUC(0−α)
KAUC(0−α)
]100 (8)

60
The method requires collection of blood samples after a single oral dose at
regular intervals of time till the entire amount of drug is eliminated from the
body. K is obtained from semilog plot of C Vs t.
DATA
Bioavailability of phenyl propanolamine hydrochloride was studied in 24 adult
male subjects. The following data represents the mean blood phenyl
propanolamine hydrochloride concentration(ng/ml) after the oral administration
of a single 25mg dose of phenylpropanolamine hydrochloride solution.
0.25 51.33
0.5 74.05
0.75 82.91
1 85.11
1.5 81.76
2 75.51
3 62.92
4 52.32
6 36.08
8 24.88
12 11.83
18 3.88
24 1.27
REPORT

61
REFERENCE

62
EXP.NO:24
DATE
DETERMINATION OF RATE OF ELIMINATION CONSTANT AND
HALF-LIFE BY URINARY EXCRETION METHOD
AIM
To determine the elimination rate constant and half-life from urinary excretion
method
DATA
The following data were taken from a graph plotted after IV administration of
100mg of drug.
Sample Time of urine
collection
Volume of urine
collected
Conc.of
unchanged drug
0 0
1 0-2 140 250
2 2-4 150 100
3 4-6 90 80
4 6-8 200 20
5 8-12 310 10
6 12-24 600 4
REPORT
The rate of elimination rate constant from urinary excretion data by urinary
excretion method was found to be
Half life was found to be

63
REFERENCES

64
EXP.NO:25
DATE
DETERMINATION OF RATE OF ELIMINATION CONSTANT AND
HALF-LIFE BY SIGMA –MINUS METHOD METHOD
AIM
To determine the elimination rate constant and half-life from urinary excretion
data by using sigma-minus method following IV administration of 100mg of
drug
DATA
The following data were taken from a graph plotted after IV administration of
100mg of drug.
Sample Time of urine
collection
Volume of urine
collected
Conc.of
unchanged drug
0 0
1 0-2 140 250
2 2-4 150 100
3 4-6 90 80
4 6-8 200 20
5 8-12 310 10
6 12-24 600 4
REPORT
The rate of elimination rate constant from urinary excretion data by sigma-
minus method method was found to be
Half life was found to be

65
REFERENCES

66
EXP.NO:26
DATE:
DATA ANALYSIS-TWO COMPARTMENT IV BOLUS
ADMINISTRATION
AIM
To determine the following pharmacokinetic parameters
DATA
The plasma concentration Vs time data following administration of 250mg of
IV bolus of dose is given plot the data and find out the pharmacokinetic
parameter (K21,K10,K12,t1/2,Vc,Vd,Vt,AUCtheoretically)
0.5 5.57
1 4.26
1.5 3.36
2 2.73
2.5 2.14
3 1.97
3.5 1.73
4 1.56
4.5 1.42
12 0.6
14 0.5
18 0.3

67
REPORT
REFERENCES

68
EXP.NO:27
DATE:
DETERMINATION OF PERCENTAGE BIOAVAILABILITY
AIM
To determine the percentage bioavailability for the following data of oral IV
drug administration
THEORY
Bioavailability means the rate and extent to which the active ingredient or
active moiety is absorbed from a drug product and becomes available at the site
of action. For drug products that are not intended to be absorbed into the
bloodstream, bioavailability may be assessed by measurements intended to
reflect the rate and extent to which the active ingredient or active moiety
becomes available at the site of action.
Relative Availability
Relative (apparent) availability is the availability of the drug from a drug
product as compared to a recognized standard. The fraction of dose systemically
available from an oral drug product is difficult to ascertain. The availability of
drug in the formulation is compared to the availability of drug in a standard
dosage formulation, usually a solution of the pure drug evaluated in a crossover
study. The relative availability of two drug products given at the same dosage
level and by the same route of administration can be obtained using the
following equation:

69
Absolute Availability
The absolute availability of drug is the systemic availability of a drug after
extravascular administration (eg, oral, rectal, transdermal, subcutaneous)
compared to IV dosing. The absolute availability of a drug is generally
measured by comparing the respective AUCs after extravascular and IV
administration. This measurement may be performed as long as V D and k are
independent of the route of administration. Absolute availability after oral drug
administration using plasma data can be determined as follows:
PROCEDURE
Cut and weigh method
Take 2 similar types of graph and then plot the graph between time Vs plasma
drug concentration. Extrapolate it to zero and cut the graph and weigh them and
calculate absolute bioavailability using formula
Absolute bioavailability =
𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑜𝑟𝑎𝑙
𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝐼𝑉
x100

70
Area method
In this method, the squares under the curve are counted. Squares having area
more than half in graph is counted and calculate bioavailability by
𝐴𝑟𝑒𝑎 𝑜𝑓 𝑜𝑟𝑎𝑙
𝐴𝑟𝑒𝑎 𝑜𝑓 𝐼𝑉
x100 [1 square = 1cm2
]
Trapezoidal method
This is most accurate method to obtain bioavailability. It involves breaking up
of plasma drug concentration Vs time profile in several trapezoids. Calculate the
areas of individual trapezoids and the add up these areas to arrive at cumulative
AUC
Area under curve trapezoid = ½(C1+C2) (t2-t1) or 1/2b (h1+h2)
𝐴𝑟𝑒𝑎 𝑜𝑓 𝑜𝑟𝑎𝑙
𝐴𝑟𝑒𝑎 𝑜𝑓 𝐼𝑉
x100
DATA
Sl.no Time (hrs.) Cp IV (µg/ml) Cp oral (µg/ml)
1 0.5 6.82 0.97
2 1 4.47 3.46
3 1.5 3.14 4.02
4 2 2.21 3.32
5 3 1.15 1.62
6 4 0.55 0.85
7 5 0.28 0.39
8 6 0.14 0.19
9 7 0.07 0.09
REPORT
The absolute bioavailability of given drug by trapezoidal method was found to
be
The absolute bioavailability of given drug by area method was found to be

71
REFERENCES

72
CALIBRATION CURVES
PREPARATION OF CALIBRATION CURVE FOR DICLOFENAC
SODIUM
Prepared a stock solution (1mg/ml) of pure drug Diclofenac sodium by
dissolving 100mg of drug in 100ml phosphate buffer6.8pH. prepared various
working standards namely 5µg/ml, 10µg/ml, 15µg/ml, 20µg/ml and 25µg/ml by
appropriate dilution from the stock solution. Measured the absorbance of these
solutions at λmax of 276nm and developed a calibration curve by plotting
concentration on x axis against the absorbance in y axis. Determined the slope
from the calibration curve.

73
PREPARATION OF CALIBRATION CURVE FOR PARACETAMOL
dissolving 100mg of drug in 100ml phosphate buffer 6.8pH. Prepared various
from the calibration curve.

74
PREPARATION OF CALIBRATION CURVE FOR DICLOFENAC
POTASSIUM
dissolving 100mg of drug in 100ml phosphate buffer6.8pH. Prepared various
from the calibration curve

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