Design and Conduct Design and Conduct of

BA/BE Studies

Central Drug Standard Control Organization’

Different Types of Studies : Pharmacokinetic Studies. Pharmacokinetic Studies.

Pharmacodynamic Studies.

Comparative Clinical trials

In-vitro studies.

Pharmacokinetic Studies.

1. Study design.

2. Study population.

3. Study condition.

4. Characteristics to be investigated.4. Characteristics to be investigated.

5. Bioanalytical methodology.

6. Statistic evaluation

7. Sp. consideration for modified release drug product.

1.Study design.

? To be answered.

Nature of I.P.

Evaluation method.

Benefits/risk.

Design period, phases, sequences & washout period.

other designs.

Single dose studies demand steady state for: Dose or time dependency, modified release products,

plasma concentration, intra-individual variability.

2.Study population.Selection of number of subjects•Error variance with 1o characteristics•Significance value should be 0.05.•Expected deviations.•Power •Number of subjects (min 16).•Sp. Cases se in subjects.

Selection criteria of subjects.•To minimize the intra and inter subject variability.•Risk to women •Risk to women •For elderly subjects (60 years or more)•Sex ratio.•Narrowing the subjects.• Risk of toxicity.

Genetic phenotyping.•Considered for exploratory bioavailability for crossover and II studies.•Genetic polymorphism.

3.Steady State Studies.Selection of Blood Sampling Points.•Single dose-immediate release product -3 ½ lifes.•Sampling Points-•3 During Absorption Phase•3-4 During Projected Tmax.

•4 During Elimination Phase.•Interval Between two Sampling Points- not over ½ hour.•Urine analysis.

Fasting and Fed State Considerations.•Fasting State:•Fasting State:•Single Dose -Fasting (10+4) hours•Multiple dose- Fasting (2 ) hours before and after dose.

• Fed State: Drug Under Fed State/modified release product.•Fed state is maintain by High fat breakfast (950-1000 Kcal.) 15 min before dose.

Steady State Studies.•Long Elimination ½ life and single dose blood concentration is not maintained•Assay sensitivity.•Compulsion of Cytotoxic Drugs.•Modified release products to see dosage fluctuations in plasma.•Drugs with intrinsic capabilities like their own metabolism.•Enteric-coated preparations where coating is innovative.•Combination products.•Drugs with non-linear pharmacokinetics.•Drugs likely to accumulate in body.

4.Characteristics to be Investigated.

BA/BE evaluation other than Biological Matrix.

• Concentration of drug/ metabolite is Low in Biological matrix.

• Limitation of Analytical method.

• Unstable or stable Drugs / metabolites.

• Drugs with short half Life.

• In Case of Prodrugs.

• Intrinsic Characteristics of drug like spatial arrangement i.e. racemate mixtures ( where achirality assay should be performed).

5.Bioanalytical Methodology{A} Pre-Study Phase

Stability of Drug/ Metabolites in BM.•Standard Condition for experiment.•Freezing and Thawing data.

Specificity/Selectivity.•Integrity of assay

Steady State Studies.•Elimination ½ life and single concentration is not maintained•Assay sensitivity.

Sensitivity.•Capacity of test procedure.

Precision and Accuracy.•Precision by replicate assay at several concentrations.•Accuracy atleast 3 concentrations(low, medium, high).

5.Bioanalytical Methodology

{A} Pre-Study Phase

Recovery.•Documentation of concentration (High, medium, low).•If low recovery, alternative method of Investigation.

Range and Linearity.Range and Linearity.• Quantitative Relation between concentration and

response.• Linear relation by standard curve with 5 concentrations

Analytical System Stability.•Assay Precision should be monitored.•Analytical standard at start and end of assays.

5.Bioanalytical Methodology

{B} Study Phase

* Acceptable variability :

“Analysis of biological samples can be done by single determination without need of reanalysis.”

* Duplicate analysis as per case to case.

* Standard curve for each analyte & used for unknown sample analyte concentration.

* No extrapolation of unknown sample.

* Instead re-determine Std. Curve or re-analyze sample after dilution.

* Quality control sample accept/reject.

5.Bioanalytical Methodology{C} Quality Control Samples

* QCS:

“Samples with known concentration prepared by spiking biological fluid with drug.”

* QCS and Standard Samples preparation at different concentrations..different concentrations..

* QCS with stable analyte preparation in fluid of interest.

* Less stable analyte preparation daily/weekly.

* QCS concentration assays with study concentration and reference concentration to that days calibration standard.

* Batch reanalysis if control sample are within

± 15 of expected concentration.

6.Statistical Evaluation.:Data Analysis:

* Primary concern in BE assessment is to limit consumer’srisk and minimize manufacturer’s risk.

:Deviation from Study Plan:* Method of analysis should be defined in the * Method of analysis should be defined in the protocol.

* Method of handling drop-outs and for handling biologically implausible outlier should be mentioned.

* Post hoc exclusion of outlier is not recommended.

* Scientific explanation for volunteer exclusion is needed

6.Statistical Evaluation

:Statistical Analysis:• SOP in protocol & BE should lead symmetry in two

formulation.

• It should account the source of variations.• It should account the source of variations.

• 90% confidence interval for population means or 5% significance level for parameter under consideration.

• Logarithmic transformation for Cmax and AUC before statistical analysis. But not recommended.

• Tmax analysis if clinically relevant, using non-parametric methods.

6.Statistical Evaluation

:Criteria for Bioequivalence:

• BE range 80-125% to obtain 90% confidence interval, which is equivalent to rejection of two one sided t-test with null hypothesis of non-equivalence at 5% significance.

• Permissible difference in bioavailability:• Narrow therapeutic index.• A serious dose related toxicity.• A steep dose/effect curve.• Non-linear pharmacokinetic within therapeutic range.

• Suprabioavailability:• Need of reformulation with fresh BE study or• Clinical data supporting the application.

7.Sp.Considerations for Modified

Release Product.General.

• MRP Include delayed , sustained, immediate + sustained delayed + sustained, immediate + delayed.

• The Product Should:• Act as Modified release & claim label.• Preclude dose dumping effect. • Provide therapeutic performance.• Provide therapeutic performance.• Produce plasma level for proposed dosing interval at steady

state.• .

Study Parameters• BA should be obtained.• Factor consideration: First market entry and Extent of

accumulation.

Study Design.• Single and Single + Multiple dose depending on accumulation,

both in fasting and non-fasting state.• Effect of food on reference:

• If known- two way crossover and • If not known –three way crossover which include:

• --Reference in fasting state.• --test in fasting state.• --test in fed state

Pharmacodynamic Studies. Healthy or patients may be used.

Necessary if quantitative analysis of drug (s) or their metabolites in plasma

or urine is not possible.

Required if drug concentration is not surrogate endpoint for efficacy and

safety demonstration.

Requirements while Planning, Conducting and Requirements while Planning, Conducting and

Assessing Pharmacodynamic Studies. • Response should claim efficacy and or safety.• Method validation for precision, accuracy and specificity.

• Investigation of Dose response: should not be maximal of test & reference.

• Quantitative measurement of response under double blind condition and

recorded with instruments which act as substitute of plasma concentration.

• Non responder should be excluded prior to screening .

• Crossover or parallel design should be used.

• Statistical considerations for assessment.

Comparative Clinical Studies.

Items to be defined in the protocol in advance: • Target parameters that represent the clinical

endpoints from which intensity

and onset of action can be derived.and onset of action can be derived.

• Size of acceptance range.

• Statistical method of analysis should be defined.

• Whenever applicable placebo design should be defined.

• Include safety endpoints.

In Vitro-Studies.

Dissolution Studies:• Carried out under mild condition at 370 ± 0.5 and

at physiological pH.

• More than 1 batch should be tested.• More than 1 batch should be tested.

• Comparative dissolution profile rather than single.

• Design:

• Individual testing of 12 dosage units of each batch where

mean and individual results should be reported.

• % of nominal content released at spaced time to achieve

virtual complete dissolution.

• Dissolution profile in 3 aq media (1-6.8 or upto 8 pH).

• Same apparatus if possible on same or consecutive days.

By: Musale M.D. MSc. Clinical Research –Ist year.

“School of Biomedicalsciences, Aurangabad”

MGM’s University of Health Sciences,

Navi Mumbai.

E. Mail : mgmmusale@gmail.com