M.pharm (Pharmaceutics) modern pharmacy unit-5 Study of consolidation parameters; Diffusion parameters, Dissolution
parameters and Pharmacokinetic parameters, Heckel plots, Similarity factors – f2
and f1, Higuchi and Peppas plot, Linearity Concept of significance, Standard
deviation , Chi square test, students T-test , ANOVA test
M.pharm (Pharmaceutics) modern pharmacy unit-5 Study of consolidation parameters; Diffusion parameters, Dissolution
parameters and Pharmacokinetic parameters, Heckel plots, Similarity factors – f2
and f1, Higuchi and Peppas plot, Linearity Concept of significance, Standard
deviation , Chi square test, students T-test , ANOVA test
This presentation includes the detail information about the physics of tablet compression and compaction, Compression, Effect of friction, distribution of forces, compaction profiles,solubility.
Theories of dispersion, pharmaceutical dispersion (Emulsion and suspension).pptxDipeshGamare
In this presentation Theories of dispersion, pharmaceutical dispersion (Emulsion and suspension) with their mechanism, methods of preparation and stability studies are mentioned.
it provide a brief note on the drug excipient interaction and various technique to find it which is a part of preformulation studies. it gives help to mpharm(pharmaceutics) students. i.
consolidation parameters, consolidation definition, consolidation parameters,
diffusion parameters,
dissolution parameters,
heckle plot, consolidation process, cold welding, fusion bonding, mechanical theory, inter molecular forces theory, liquid surface film theory, factors effecting consolidation, driving froces that facilitate diffusion, parameters related to diffusion in drug release, parameters in dissolution process, affect of agitation on dissolution, effect of dissolution fluid on dissolution, pH on dissolution fluid, viscosity effect on dissolution, effect of temperature on dissolution, pharmacokinetics parameters, C max, T max, AUC(area under curve), heckel plot, application and limitations of heckel plot, methods to compare dissolution profile, model independent method(F1 AND F2)difference factor, similarity factors, limits of difference factor and similarity factors, higuchi model(Diffusion matrix formulation), korsmeyer peppas model(the power law).
This presentation includes the detail information about the physics of tablet compression and compaction, Compression, Effect of friction, distribution of forces, compaction profiles,solubility.
Theories of dispersion, pharmaceutical dispersion (Emulsion and suspension).pptxDipeshGamare
In this presentation Theories of dispersion, pharmaceutical dispersion (Emulsion and suspension) with their mechanism, methods of preparation and stability studies are mentioned.
it provide a brief note on the drug excipient interaction and various technique to find it which is a part of preformulation studies. it gives help to mpharm(pharmaceutics) students. i.
consolidation parameters, consolidation definition, consolidation parameters,
diffusion parameters,
dissolution parameters,
heckle plot, consolidation process, cold welding, fusion bonding, mechanical theory, inter molecular forces theory, liquid surface film theory, factors effecting consolidation, driving froces that facilitate diffusion, parameters related to diffusion in drug release, parameters in dissolution process, affect of agitation on dissolution, effect of dissolution fluid on dissolution, pH on dissolution fluid, viscosity effect on dissolution, effect of temperature on dissolution, pharmacokinetics parameters, C max, T max, AUC(area under curve), heckel plot, application and limitations of heckel plot, methods to compare dissolution profile, model independent method(F1 AND F2)difference factor, similarity factors, limits of difference factor and similarity factors, higuchi model(Diffusion matrix formulation), korsmeyer peppas model(the power law).
This presentation discusses the correlation of dissolution with In-vitro In-vivo correlation, Effect of Selection of Dissolution Apparatus and Dissolution Medium on IVIVC, BCS classification and levels of IVIVC.
NIOSOMES , GENERAL CHARACTERISTICS OF NIOSOME , TYPES OF NIOSOMES , OTHERS TYPES OF NIOSOMES , NIOSOMES VS LIPOSOMES , COMPONENTS OF NIOSOMES , Non-ionic surfactant , Cholesterol , Charge inducing molecule , METHOD OF PREPARATION , preparation of small unilamellar vesicles , Sonication , Micro fluidization , preparation of large unilamellar vesicles , Reverse Phase Evaporation , Ether Injection , preparation of Multilamellar vesicles , Hand shaking method , Trans membrane pH gradient drug uptake process (remote loading) , Miscellaneous method :Multiple membrane extrusion method , The “Bubble” Method , Formation of Niosomes From Proniosomes , SEPARATION OF UNENTRAPPED DRUGS , Gel Filtration , Dialysis , Centrifugation , FACTORS AFFECTING THE PHYSICOCHEMICAL PROPERTIES OF NIOSOMES , Membrane Additives , Temperature of Hydration , PROPERTIES OF DRUGS , AMOUNT AND TYPE OF SURFACTANT
Structure of Surfactants , Resistance to Osmotic Stress , Characterization of niosomes ,Therapeutic applications of Niosomes , For Controlled Release of Drugs , To Improve the Stability and Physical Properties of the Drugs , For Targeting and Retention of Drug in Blood Circulation , Proniosomes , Aspasomes , Vesicles in Water and Oil System (v/w/o) ,Bola - niosomes , Discomes , Deformable niosomes or elastic niosomes , According to the nature of lamellarity ,Small Unilamellar vesicles (SUV) 25 – 500 nm in size.,Large Unilamellar vesicles (LUV) 0.1 – 1μm in size , Multilamellar vesicles (MLV) 1-5 μm in size , According to the size:Small Niosomes (100 nm – 200 nm) , Large Niosomes (800 nm – 900 nm),Big Niosomes (2 μm – 4 μm)
Drug absorption from git , Drug absorption from git , DIGESTION AND ABSORPTION , Transcellular / intracellular , transport , .Passive Transport Processes , Passive diffusion , Pore transport , Ion- pair transport , Facilitated or mediated diffusion
, Active transport processes , Primary , Secondary , Symport (Co-transport) , Antiport (Counter transport) , Paracellular / Intercellular Transport , Permeation through tight junctions of epithelial cells , Persorption , Vesicular or Corpuscular Transport (Endocytosis) , Pinocytosis , Phagocytosis , FACTORS INFLUENCING ABSORPTION OF DRUGS , DRUG DISSOLUTION , Factors affecting dissolution rate , DISSOLUTION APPARATUS , IVIVC (In vitro- in vivo correlation) , ROLE OF DOSAGE FORM , Transport model , pH Microclimate , Intracellular pH environment , Tight junction complex
Cold cream , vanishing cream , IDEAL PROPERTIES OF VANISHING CREAMS , MAJOR INGREDIENTS USED FOR THE PRODUCTION OF VANISHING CREAMS , FORMULATION OF VANISHING CREAM , IDEAL CHARACTERISTICS OF COLD CREAM , INGREDIENTS USED FOR PREPARATION OF COLD CREAM , FORMULATION OF COLD CREAM
HERBAL INGREDIENTS USED IN HAIR CARE , cosmetics , herbal cosmetics , Herbal ingredients used in the cosmetics , preparation for hair , Hair oil , Shampoos , Hair dye , Hair lotion , Ingredient used in Herbal hair oil , Marketed herbal hair oil , Evaluation of herbal hair oil , Ingredient used in Herbal shampoo , Marketed herbal shampoo , Evaluation of herbal shampoo , Ingredient used in the herbal hair dye , Marketed herbal hair dye , Evaluation of herbal hair dye
cosmetics - regulatory : Regulatory provisions related to cosmetics PV. Viji
REGULATORY PROVISIONS RELATED TO COSMETICS , REGULATORY PROVISIONS RELATING TO IMPORT OF COSMETICS , Application for registration certification for import cosmetics , Grant of registration certificate , Standards for imported cosmetics , REGULATORY PROVISIONS RELATING TO MANUFACTURE OF COSMETICS , REQUIREMENTS OF FACTORY PREMISES FOR MANUFACTURE OF COSMETICS , LOAN LICENCE
INDIAN REGULATORY REQUIREMENTS FOR LABELING OF COSMETICSPV. Viji
INDIAN REGULATORY REQUIREMENTS FOR LABELING OF COSMETICS , IMPORTANCE OF LABELING , LABELING REQUIREMENTS , Common or generic name of the product. , Product function , Use instruction , Name & address of Manufacturer , Country of manufacture , Manufacture Date , Expiry date , Net Quantity , Retail Sale Price , Storage condition , Barcodes , Batch number , Warning or Caution if hazard exists , Manufacturing License Number , Ingredients , Registration Certificate Number (RCN) , Consumer Care Details , Using Stickers , Brown/Red or green dot , Not a standard pack size under Legal Metrology(Packaged commodities) Rules
Statistical modeling in pharmaceutical research and developmentPV. Viji
Statistical modeling in pharmaceutical research and development , Statistical Modeling , Descriptive Versus Mechanistic Modeling , Statistical Parameters Estimation , Confidence Regions , Non Linearity at the Optimum , Sensitivity Analysis , Optimal Design , Population Modeling
Computational modeling of drug dispositionPV. Viji
Computational modeling of drug disposition , Modeling techniques , Drug absorption , solubility , intestinal permeation , Drug distribution , Drug excretion , Active Transport , P-gp , BCRP , Nucleoside transporters , hPEPT1 , ASBT , OCT , OATP , BBB-choline transporter
NMR SPECTROSCOPY ,Relaxation,longitudinal / spin- spin relaxation,transverse / spin- spin relaxation,Shielding of proton ,Deshielding of proton,CHEMICAL SHIFT,Factors Influencing Chemical Shift,Inductive effect, Vander Waal’s deshielding,Anisotropic effect (space effect),Hydrogen bonding
,SPLITTING OF THE SIGNALS,COUPLING CONSTANT,NMR SIGNAL IN VARIOUS COMPOUND
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
2. CONSOLIDATION
An increase in the mechanical strength of the
material resulting from particle or particle
interaction. ( Increasing in mechanical strength of
the mass)
3. CONSOLIDATION PROCESS
Cold welding:
when the surfaces of two particles approach each other
closely enough, their free surface energies results in strong
attractive force, a process known as cold welding.
Fusion bonding:
Multiple point contacts of the particle upon application of
load produces heat which causes fusion / melting. Upon
removal of load it gets solidified and increase the mechanical
strength of mass.
4.
5. CONSOLIDATION MECHANISMS
Mechanical theory:
As the particles undergo deformation, the particle boundaries
that the edges of the particle intermesh, forming a mechanical
bond.
Intermolecular forces theory:
Under pressure the molecules at the point of true contact
between new, clean surface of the granules are close enough so
that van der Waals forces interact to consolidate the particle.
6. Liquid-surface film theory:
Thin liquid films form which bond the particles together at the
particle surface. The energy of compression produces melting of
solution at the particle interface followed by subsequent
solidification or crystallization thus resulting in the formation of
bonded surfaces
7. FACTORS AFFECTING CONSOLIDATION:
The chemical nature of the material
The extent of the available surface
The presence of surface contaminants
The inter surface distance
9. DIFFUSION PARAMETERS
This is given by Higuchi.
𝑄 = 𝐾√𝑻
Where
Q is the amount of drug released in time‘t’ per unit area,
K is higuchi constant
T is time in hr.
Plot: The data obtained is to be plotted as cumulative percentage
drug release versus Square root of time.
Application: modified release pharmaceutical dosage forms,
transdermal systems and matrix tablets with water soluble drugs.
11. DISSOLUTION PARAMETERS
Dissolution is a process in which a solid substance solubilizes in a given
solvent i.e. mass transfer from the solid surface to the liquid phase.
Dissolution parameters:
Effect of agitation
Effect of dissolution fluid
Influence of pH of dissolution fluid
12. Effect of viscosity of the dissolution medium
Effect of the presence of unreactive and reactive additives in the dissolution
medium.
Volume of dissolution medium and sink conditions
Deaeration of the dissolution medium
Effect of temperature of the dissolution medium
13. EFFECT OF AGITATION
The relationship between the intensity of agitation and the
rate of dissolution varies considerably according to the type
of agitation used, the shape and design of the stirrer and
the physicochemical properties of the solid.
For the basket method, 100 rpm usually is utilized, while for
the paddle procedure, a 50 – 75 rpm is recommended.
14. EFFECT OF DISSOLUTION FLUID
Selection of proper medium for dissolution testing depends
largely on the physicochemical properties of the drug.
15. INFLUENCE OF PH OF DISSOLUTION
FLUID
simulated gastric fluid as the test medium for tablets containing
ingredients which reacted more readily in acid solution than in
water (e.g., calcium carbonate).
16. EFFECT OF VISCOSITY OF THE
DISSOLUTION MEDIUM
If the interaction at the interfaces, occurs much faster than the rate
of transport, such as in the case of diffusion controlled dissolution
processes, it would be expected that the dissolution rate decreases
with an increase in viscosity.
The rate of dissolution of zinc in HCl solution containing
sucrose was inversely proportional to the viscosity of solution.
17. EFFECT OF THE PRESENCE OF UNREACTIVE AND
REACTIVE ADDITIVES IN THE DISSOLUTION
MEDIUM.
When neutral ionic compounds, such as sodium chloride and
sodium sulfate, or non ionic organic compounds, such as
dextrose, were added to the dissolution medium,the dissolution
of benzoic acid was dependent linearly upon its solubility in the
particular solvent.
When certain buffers or bases were added to the aqueous
solvent , an increase in the dissolution rate was observed.
18. VOLUME OF DISSOLUTION MEDIUM
AND SINK CONDITIONS
The proper volume of the dissolution medium depends mainly
on the solubility of the drug in the selected fluid.
If the drug is poorly soluble in water, a relatively large amount
of fluid should be used if complete dissolution is to be
expected.
19. DEAERATION OF THE DISSOLUTION
MEDIUM
Presence of dissolved air or other gases in the dissolution
medium may influence the dissolution rate of certain
formulations and lead to variable and unreliable results.
Example, the dissolved air in distilled water could significantly
lower its pH and consequently affect the dissolution rate of
drugs that are sensitive to pH changes, e.g., weak acids.
20. EFFECT OF TEMPERATURE OF THE
DISSOLUTION MEDIUM
Drug solubility is temperature dependent, therefore careful
temperature control during the dissolution process is extremely
important.
Generally a temperature of 37°±0.5 is maintained during
dissolution determination of oral dosage forms and suppositories.
For topical preparations as low as 30° and 25°have been used.
22. PHARMACOKINETIC PARAMETERS
Pharmacokinetics is defined as the kinetics of drug absorption,
distribution, metabolism, and excretion and their relationship
with pharmacologic, therapeutic or toxicologic response in
mans and animals.
24. Three important pharmacokinetic parameters:
Peak plasma concentration (Cmax)
Time of peak concentration (tmax)
Area under the curve (AUC)
25. PEAK PLASMA CONCENTRATION (Cmax)
The point of maximum concentration of a drug in plasma is called
as peak and the concentration of drug at peak is known as peak
plasma concentration.
It is also called as peak height concentration and maximum drug
concentration.
Cmax is expressed in mcg/ml.
26. TIME OF PEAK CONCENTRATION (tmax)
The time for drug to reach peak concentration in plasma ( after
extravascular administration) is called the time of peak
concentration.
It is expressed in hours.
27. AREA UNDER THE CURVE (AUC)
It represents the total integrated area under the plasma level-
time profile and expresses the total amount of drug that comes
into the systemic circulation after its administration.
AUC is expressed in mcg/ml X HRS.
It is important for the dugs that are administered repetitively for
the treatment of chronic conditions like asthma or epilepsy.
29. SIMILARITY FACTORS f1 AND f2
DIFFERENCE FACTOR (f1)
The difference factor (f1) as defined by FDA calculates the %
difference between 2 curves at each time point and is a
measurement of the relative error between 2 curves.
where,
n = number of time points
Rt = % dissolved at time t of reference product (prechange)
Tt = % dissolved at time t of test product (post change)
30. SIMILARITY FACTOR (F2)
The similarity factor (f2) as defined is a measurement of the
similarity in the percentage (%) dissolution between the
two curves
31. LIMITS FOR SIMILARITY AND DIFFERENCE
FACTORS
Inference
Dissolutions profile
are similar
Similarity or
equivalence of two
profiles
≥50≤15
0 100
Differencefactor Similarityfactor
32. Data structure and steps to follow:
This model-independent method is most suitable for the
dissolution profile comparison when three to four or more
dissolution time points are available.
Determine the dissolution profile of two products (12 units each)
of the test (post-change) and reference (pre-change) products.
33. Some recommendations:
The dissolution measurements of the test and reference
batches should be made under exactly the same conditions.
The dissolution time points for both the profiles should be the
same (e.g. 15, 30, 45, 60 minutes).
34. Advantages
They are easy to compute.
They provide a single number to describe the comparison of
dissolution profile data.
Disadvantages
The basis of the criteria for deciding the difference or
similarity between dissolution profile is unclear.
36. HECKEL EQUATION
The heckel analysis is a most popular method of deforming
reduction under compression pressure .
Powder packing with increasing compression load is normally
attributed to particles rearrangement , elastic & plastic
deformation & particle fragmentation.
37. It is analogous to first order reaction ,
Log 1/E= Ky . P + Kr
Where
Ky =material dependent constant inversely proportional to
its yield strength ‘s’
Kr=initial repacking stage hence E0
38. The applied compressional force F & the movement of the
punches during compression cycle & applied pressure P , porosity
E.
For a cylindrical tablets
p=4F/л. D2
Where…
D is the tablet diameter similarly E can be calculated by
E=100.(1-4w/ρt .л.D2.H)
Where…
w is the weight of the tableting mass ,
ρt is its true density ,
H is the thickness of the tablets.
39. HECKEL PLOTS
Heckel plot is density v/s applied pressure
Follows first order kinetics
Materials that are comparatively soft & that readily undergo plastic
deformation retain different degree of porosity , depending upon
the initial packing in the die.
40. This in turn is influenced by the size distribution , shape etc of
the original particles.
Ex: sodium chloride (shown by type a in graph)
Harder material with higher yield pressure values usually
undergo compression by fragmentation first , to provide a
denser packing.
Ex: Lactose, sucrose ( shown in type b in graph).
41. Type-a plots exhibits higher slop (Ky) then type-b. because
type-a materials have lower yield stress.
Type-b plots exhibits lower slop because brittle , hard
materials are more difficult to compress.
42. APPLICATION OF HECKEL EQUATION
The crushing strength of tablets can be correlated with the values of
k of the Heckel plot .
Larger k values usually indicate harder tablets.
Such information can be used as a means of binder
selection when designing tablet formulations.
Heckel plots can be influenced by the overall time of compression,
the degree of lubrication and even the size of the die, so that the
effects of these variables are also important and should be taken
into consideration
44. HIGUCHI MODEL
The first example of a mathematical model aimed to describe drug
release from a matrix system was proposed by Huguchi in 1961.
This model is based on the hypothesis that
(i) drug diffusion takes place only in one dimension
(ii) drug particles are much smaller than system
thickness
(iii) drug diffusivity is constant
(iv) perfect sink conditions are always attained in the
release environment.
45. Accordingly, model expression is given by the equation:
ft = Q = A √D(2C ñ Cs) Cs t
where
Q is the amount of drug released in time
t per unit area A,
C is the drug initial concentration,
Cs is the drug solubility in the matrix media and
D is the diffusivity of the drug molecules (diffusion coefficient)
in the matrix substance.
46. In a general way it is possible to simplify the Higuchi model as
(generally known as the simplified Higuchi model):
f t = Q = KH x t1/2
where,
KH is the Higuchi dissolution constant.
The data obtained were plotted as cumulative percentage drug
release versus square root of time .
Application: This relationship can be used to describe the drug
dissolution from several types of modified release
pharmaceutical dosage forms, as in the case of some
transdermal systems and matrix tablets with water soluble
drugs.
48. KORSMEYER-PEPPAS MODEL
Korsmeyer et al. (1983) derived a simple relationship which
described drug release from a polymeric system equation .
To find out the mechanism of drug release, first 60% drug release
data were fitted in Korsmeyer-Peppas model
49. Mt / M∞ = Ktn
where
Mt / M∞ is a fraction of drug released at time t,
k is the release rate constant and
n is the release exponent.
The n value is used to characterize different release for
cylindrical shaped matrices.
50. To find out the exponent of n the portion of the release curve,
where
Mt / M∞ < 0.6
should only be used.
To study the release kinetics, data obtained from in vitro
drug release studies were plotted as log cumulative
percentage drug release versus log time.
53. CHI-SQUARE TEST
Karl Pearson introduced a test to distinguish whether an
observed set of frequencies differs from a specified
frequency distribution
The chi-square test uses frequency data to generate a
statistic
56. Chi- Square Test as a Non-Parametric
Test
Test of Goodness of Fit.
Test of Independence.
57.
58. 2.AS A TEST OF GOODNESS OF
FIT
It enables us to see how well does the assumed theoretical
distribution(such as Binomial distribution, Poisson
distribution or Normal distribution) fit to the observed data.
When the calculated value of χ2 is less than the table
value at certain level of significance, the fit is considered
to be good one and if the calculated value is greater than
the table value, the fit is not considered to be good.
59.
60. 3.AS A TEST OF INDEPENDENCE
χ2 test enables us to explain whether or not two attributes
are associated. Testing independence determines whether
two or more observations across two populations are
dependent on each other (that is, whether one variable
helps to estimate the other. If the calculated value is less
than the table value at certain level of significance for a
given degree of freedom, we conclude that null hypotheses
stands which means that two attributes are independent or
not associated. If calculated value is greater than the table
value, we reject the null hypotheses.
61. Steps involved
1)Determine The Hypothesis:
Ho : The two variables are independent
Ha : The two variables are associated
2) Calculate Expected frequency
68. Student’s t-test
The test is used to compare samples from two different
batches.
It is usually used with small (<30) samples that are
normally distributed.
69. There are two types of t-test:
Matched pairs
independent pairs
122. ANALYSIS OF VARIANCE
(ANOVA)
The analysis of variance(ANOVA) is developed by
R.A.Fisher in 1920.
The technique of variance analysis developed by fisher is
very useful in such cases and with its help it is possible to
study the significance of the difference of mean values of a
large no.ofsamples at the same time.
123. CLASSIFICATION OF ANOVA
The Analysis of variance is classified into two ways:
One-way classification
Two-way classification
In a one-way classification we take into account the
effect of only one variable.
If there is a two way classification the effect of two
variables can be studied.
124. One Way ANOVA
Steps
1. State null & alternative hypothesis
2.State Alpha
3.Calculate degrees of Freedom
4.State decision rule
5. Calculate test statistic
6.Calculate F statistic
125.
126. 1)Null hypothesis
No significant difference in the means of 3 samples
2)State Alpha i.e 0.05
3)Calculate degrees of Freedom
k-1 & n-k= 2 & 12
4)State decision rule
Table value of F at 5% level of significance for d.f 2 & 12
is
3.88
The calculated value of F > 3.88 ,H0 will be rejected
129. Sum of squares between samples (SSC)
Sum of squares between samples (SSC) =
n1 (M1 – Grand avg)2+n2 (M2– Grand avg)2+n3(M3– Grandavg)2
5 ( 10- 10)2 + 5( 8- 10)2 + 5 ( 12- 10)2 =40
132. Two Way ANOVA
Example
we have test score of boys & girls in age group of 10 yr,11yr &
12 yr. If we want to study the effect of gender & age on score.
Two independent factors- Gender, Age Dependent factor -
Test score
133. Source of variance d.f Sum of
square
s
Mean sumof
squares
F-Ratio
Between
samples(colum
ns)
d f 1=C-1 SSC=B-D MSC=SSC̸ d f F=MSC̸ MSE
Between
Replicants(row
s)
d f 2=r-1 SSR=C-D MSR=SSR̸ d f 2
Within
samples(Residu
al)
d f3=(c-1)(r-
1)
SSE=SST-
(SSC+SS
R)
MSE=SSE̸ d f3 F=MSR̸ MSE
Total n-1 SST=A-D
134. APPLICATIONS OF ANOVA
Similar to t-test
More versatile than t-test
ANOVA is the synthesis of several ideas & it is used for
multiple purposes.
The statistical Analysis depends on the design and
discussion of ANOVA therefore includes common statistical
designs used in pharmaceutical research
135. In the bioequivalence studies the similarities between the
samples will be analyzed with ANOVA only.
Pharmacokinetic data also will be evaluated using ANOVA.
Pharmacodynamics (what drugs does to the body) data
also will be analyzed with ANOVA only.