Grade Statistics without Bonus with Bonus Average = 86 Median = 87 Average = 88 Median = 89 Undergraduates Average=88 MS Average=92
Advice for Next Test Normalized means /kg, unless otherwise specified – Normalized dose = mg/kg Don’t totally depend on the handouts – Check website for changes and updates, student questions answered, etc. Bonus Points – Rules on the (0.5 and 1.0 points)
Advice for Next Test Multiply Normalized Values by the weight. – V Normalized = 0.1 L/kg – V = 0.1 L/kg * 70 kg = 7L (Experts Only) Keep normalized values consistent.
MS Project NCA Modeling Project due today Due 9/28/15: More Comprehensive Project – Plotting – Table – NCA – Compartment Modeling (Classic) Grading?
MS Project Your Own Data to Analyze4 Excercises
BIOAVAILABILITY Lecture #14
AUC?, C MAX ?, t MAX ?, k a ?, k? Elimination “Rate” Limiting ~Slope Shallow ~Slope Steep
Bioavailability
Drug Interactions My version Book’s Cryptic Version
Relative Bioavailability Dosage Forms Different Extravascular Administration Routes Different Conditions
Relative Bioavailability (A vs. B)
Dosage Forms Tablet Capsule
Extravascular Administration Routes Oral Intramuscular (I.M.)
Conditions Without food With food
Urine Data
Bioavailability and Urine
Relative Bioavailability and Urine
Assessment of Product Performance Formulation – Biopharmaceutics – Excipients Bioequivalence (BE) Bioavailability (BA) and BE Testing
Biopharmaceutics Physical/Chemical Drug Properties Dosage Form (Tablet, Capsule) – Formulations (Industry) Route of Administration Rate/Extent of Systemic Drug Exposure
Excipients Inactive stuff that you put with the drug Natural/Synthetic Bulking up the formulation – “bulking agents”, “fillers”, “diluents” Therapeutic Enhancement – drug absorption – solubility
Bioequivalence Essentially similar – Different Dosage Forms/Same PK Generic products 0.8 to 1.25 (Test/Reference Ratio) 90% CI AUC and C MAX
On the NDA = New Drug Application IND = Investigational New Drug Application Not in Textbook
BA and BE Testing: Study Types Longitudinal Study – Same Subjects over a Period of Time – Cohort (Defined)/Panel (Cross-Section) – Retrospective Clinical Trials – Randomized – Crossover – Blind, Double blind and Triple Blind
Randomized vs. Crossover Clinical Trials Tablet Patient 1 Capsule Patient 2 Placebo Patient 3 Randomized (Treatments Random) Tablet Capsule Placebo Capsule Tablet Placebo Tablet Capsule Placebo Patient 1 Patient 2 Patient 3 Crossover (Sequence of Treatments Random)
Randomized vs. Crossover Trials Randomized – Pros Relatively simple to execute. Not susceptible to carry-over effects. – Cons Wide variation significant error in the analysis. Crossover – Pros Compare treatments with a patient, so variation between patients is eliminated – Cons Susceptible to carry-over effects.
Blind Clinical Trials Patient Receiving the Drug Person Administering the Drug Person Overseeing the Trial Blind Double BlindBlind Triple BlindBlind
BA and BE: Considerations by the FDA Study Type Dosing Frequency What is measured? PK? Other Documentation (Lots)
Study Type Pilot Study – 8-12 Subjects Full-Scale – Subjects >18 years old and healthy Cohort or Panel – (gender?) Fasting conditions (>10 hours overnight)
Dosing Frequency Single Dose – Preferred – Easier to assess PK parameters than multiple dose (steady state) Multiple Dose – Differences absorption rate, not the extent of absorption. – Excessive variability in bioavailability (BA) – [drug] plasma too low with single dose – Extended release dosage form
Moieties to be Measured Preferred: Active Ingredient or moiety Active Metabolite – [Active ingredient or moiety] too low – Contributes to safety/efficacy
PK? Appropriate Fluid: blood, plasma, serum PK – Peak Exposure: C MAX (Directly Plasma) t max – Total Exposure AUC – Partial Exposure Partial AUC MEC = Minimum Effective Concentration MTC = Minimum Toxic Concentration
Other In vitro to human in vivo correlation (IVIVC) – in vitro dissolution/drug-release characterization PD studies – not recommended for orally administered drugs – PK measurements preferred (More accurate/sensitive/reproducible) – only if PK fails Clinical Endpoints (e.g. Cured) (Rare) In vitro (e.g. dissolution testing)
Bioavailability Example Parameters AUC ev = (mg*hr)/L A ev = 7 mg F? AUC iv = (mg*hr)/L A iv = 4 mg