Presentation on theme: "Bioavailability Bioavailability means the rate and extent to which the active substance is adsorbed from a pharmaceutical product and become available."— Presentation transcript:
2BioavailabilityBioavailability means the rate and extent to which the active substance is adsorbed from a pharmaceutical product and become available at the site of action
3BioequivalenceTwo medical products are bioequivalent if they are pharmaceutical equivalent or pharmaceutical alternatives and if their bioavailabilities after administration in the same molar dose are similar to such degree that their effects, with respect to both efficicy and safety, will be essentially the same
4Design and conduct of studies The study should be designed in such a way that the formulation effect can be distinguished from other effects.Most common is a two-period, two-sequence crossover design, if the formulations to be compared is twoSingle dose studiesSteady-state studies
5Design and conduct of studies Adequate wash out periods between treatmentsSampling scheduleto provide an adequate estimation of Cmaxto cover the plasma concentration time curve long enough, 80% of AUC24 hours cycle at steady state?drugs with long half-life?
6Subjects Healthy volunteers The inclusion/exclusion criteria should be clearly stated in the protocolBoth sex18-55 years oldNormal weightScreened forlaboratory testmedical historymedical examinationpreferable non-smokers and without a history of alcohol or drug abuse
7Chemical analysisThe bioanalytical part of bioequivalence trials should be conducted according to the applicable principle of Good Laboratory Practice (GLP)
8Good Laboratory Practice (GLP) Test plan (Analytical protocol)Sample traceabilityDocumentation, possible to reconstruct the studyAnalytical method validation reportAnalytical report signed by responsible investigator
9Pre-study phase The method used must be well characterised Stability SpecificityAccuracyPrecisionLimit of quantitationResponse function
10Validation objectiveTo demonstrate that the analytical procedure is suitable for its intended purpose
13Specificity (selectivity) Ability of an analytical method to measure only what it is intended to measureBlank samples from six different subjectsWill other drugs, metabolites or endogenous components interfere in the measurements?
14AccuracyThe closeness of mean test results obtained by the analytical method to the true value (concentration) of the analyte.
15Accuracy Accuracy should be measured at minimum 3 levels At least 5 determinations per concentrationThe mean value should be within 15% of the actual valueAt the lower limit of quantitation level within 20% is acceptedxxxxxx
16PrecisionThe closeness of individual measurements of an analyte when the procedure is applied repeatedly to multiple aliquotes of a single homogenous volume of biological matrix
17Precision Precision should be measured at minimum 3 levels At least 5 determinations per concentrationThe calculated CV should not exceed 15%At the lower limit of quantitation level, CV should not exceed 20%Subdivided into within-run and between-run
18Precision and Accuracy Conc.AccuracyPrecisionnnmol/l(%)Within-runBetween-run%%0.722.214.171.124126.96.36.19981188.8.131.528
19Recovery The extraction efficiency of an analytical method Recovery of an analyte need not be 100%
20Lower limit of quantitation The lowest standard on the calibration curve should be accepted as the lower limit of quantitation (LLOQ)if
21Lower limit of quantification The analyte responce at LLOQ is at least 5 times the blank responseThe peak should be identifiable and discretePrecision within 20% CVAccuracy of %
23Calibration/Standard curve A calibration curve is the relation between instrument response and known concentrations of the analyteShould be prepared in the same biological matrix as the samplesShould consist of 6-8 samples covering the expected rangeShould include LLOQ and a blank sampleShould include a zero sample (with internal standard)Same curve fitting, weighting in prestudy and studyAny changes should be documented
30ReferencesGuidance for Industry Bioanalytical Method Validation FDA, May 2001Workshop Report: Shah, V.P. Et al., Pharmaceutical Research: 1992; 9:Workshop Report: Shah, V.P. et al., Pharmaceutical Research: 2000; 17:
31Costs Validation = 130-180.000 SEK Stability = SEK for each time pointQA = SEK/study
32The study phase (1)...in which the validated bioanalytical method is applied to the actual analysis of samples from the biostudy mainly in order to confirm the stability, accuracy and precision.
33The study phase (2) Calibration curve in each run Six Quality Control samples in each runPre-stablished SOPs for procedures (method)Acceptance criteria for a run - accuracy and precision of the calibration curve - accuracy and precision of the QC samples - repeat analysisIt is preferable to analyse all study samples from a subject in a single run
34The study phase (3)The QC samples should be used to accept or reject the run (2 samples at 3 levels)Four QC samples out of six should be within 15% of their nominal valueTwo QC samples can be outside ±15% but not both at the same concentration
35System suitability test The lowest calibration sample is injected before each run.The system is accepted if:Signal to noise ratio is above 5 for the substance.The peak shape is acceptable after visual inspection of the chromatogramThe retention times are within 10% of the previous run.
36The analytical report should include Results for all calibration curvesResults for all quality control samplesRepresentative number of chromatogramsShould include data from subjects who eventually dropped-outReanalysed samples and the reason for reanalysesThe analytical validation reportThe responsible investigator(s) should sign for their respective section of the report
37Chiral active substances The bio-analytical method should be enantiomericUnlessBoth products contain the same stable singel enantiomerBoth products contain the racemate and both enantiomers show linear pharmacokinetics
38Also guidance for Reference and test product Data analysis In vitro dissolution comlementary to a bioequivalence studyReporting of resultsApplication for products containing new active substancesApplication for products containing approved active substancesis given