Biopharmaceutics. Lecture :1. Module Introduction and Introduction to Biopharmaceutics

Transcription

1 Biopharmaceutics Lecture :1 Module Introduction and Introduction to Biopharmaceutics Assist. Lecturer Ali Yaseen Ali BSc Pharmacy MSc Industrial Pharmaceutical Sciences Dept. of Pharmaceutics School of Pharmacy University of Sulaimani 1

2 Assit Lecturer Ali Yaseen Ali Education BSc Pharmacy (HMU) MSc Industrial Pharmaceutical Sciences (University of Brighton) Nanoparticles (Carbon) in Drug Delivery (CNT) Nanomedicine CPD (University of Oxford) Room: Pharmaceutics Dept (New building) Sun-Thursday Drop-in or with specific query: 2

3 Syllabus Introduction to biopharmaceutics Biopharmaceutical aspects of oral drugs: Physiological factors affecting the absorption of drugs from GIT Physicochemical Factors of drugs affecting absorption Dosage form factors affecting the drug absorption from the GIT 3

4 Lectures Organisation Theoretical Lectures: 2 hours weekly Sundays 11:30-1:30 Mondays 8:30-10:30 Practice (Lab Sessions) Saturday 3 hours 4

5 Recommended Texts Aulton's Pharmaceutics: The Design and Manufacture of Medicines, M.E.Aulton, Churchill Livingstone, Pharmaceutical Dosage forms and Drug Delivery Systems by Haward A. Ansel; latest edition Shargel L, Yu AB, (Eds.), Applied Biopharmaceutics and Pharmacokinetics. 5

6 Assessment Mid-term(semester) :40% Theory: written exam (1-1.5 hour) 25 % Practical : 15% Lab session works, attendance, quizes End-of-Semester : 60 % Practical: written exam (1 hour) 10% Theoretical: written exam (3 hours) 50 % Pass mark is 50% 6

7 Assessment Criteria MCQ and short answer questions Factual knowledge Understanding of key concepts Ability to apply knowledge of concepts to new scenarios Calculations 7

8 Assessment Criteria Written exam long answer questions Demonstrate understanding / knowledge of the issues relating to appropriate topics Consequences/ implications of. Ability to construct an argument supporting/ refuting a position(s) compare and contrast two positions Ability to make appropriate analysis of data Calculations 8

9 Specimen questions Will be provided with specimen questions and marking schemes 9

10 The learning pyramid Application Understanding Knowledge 10

11 Introduction to Biopharmaceutics 11

12 Drugs A substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease. A substance (other than food) intended to affect the structure or any function of the body. 12

13 Dosage Forms A dosage form is the physical form in which a drug is produced and dispensed, such as a tablet, a capsule, or an injectable. 13

14 Route of Administration A route of administration is a way of administering a drug to a site in a patient 14

15 What is Biopharmeceutics? 15

16 Pharmacokinetics Is the science of kinetics of drug Absorption, Distribution, Metabolism of Elimination (ADME) It studies the time course of ADME. It is used in clinical settings to enhance safe and effective therapeutic management of individual patients. 16

17 Biopharmaceutics Physicochemical properties Bioavailability (Rate & Extent) Dosage form Route of Administration 17

18 Biopharmaceutics Science that studies how the physicochemical properties of the drug, its dosage form and the route of administration affect the rate and extent of absorption (Bioavailability). 18

19 Background (Aulton and Taylor 2013) 19

20 Concentration of drug in blood [bound drug] + [unbound drug] = [total drug] Represents amount of drug at site of action Depends on: The amount of drug Absorbed The extent of Distribution of the drug The rate of Metabolism of the drug The rate of Elimination of the drug 20

21 Typical Blood-plasma Concentration Time Curve of A Tablet Taken By Single Dose 6 Absorption phase Elimination phase Average serum concntration (mcg/ml) Maximum safe concentration Therapeutic range Minimum effective concentration Duration of action Time after drug administration (h) 21

22 Bioavailability The primary concern of Biopharmaceutics IV (100%) bioavailable. Other routes? Bioavailable dose Fraction of administered dose reaching systemic circulation in an unchanged form 22

23 Bioavailability Relative amount of an administered dose of a drug that reaches the systemic circulation intact Rate at which this occurs 23

24 Bioavailability - definition Rate and extent to which an active agent is absorbed into the systemic circulation. 24

25 Routes of Administration 25

26 Oral route Most popular Natural and convenient for patient Relatively easy to manufacture oral dosage forms Compact Not sterilized Inexpensive 26

27 Biopharmaceutical Factors influencing the rate and extent of absorption Foods eaten by patient? Effect of disease state on drug absorption Age of patient Site of absorption Co-administration of other drugs 27

28 Biopharmaceutical Factors influencing the rate and extent of absorption Physical and chemical properties of drug Type of dosage form Composition and method of manufacture of the dosage form Size of dose Frequency of administration 28

29 Conditions in Biopharmaceutics For a given drug, bioavailability may vary if: 1. Same dosage form, but different route 2. Same route but different dosage form 3. Same route and same type of dosage form but different formulations 29

30 For a given drug, bioavailability may vary if: Same dosage form, but different route Both solutions 30

31 Equivalent doses of same drug administered by IV bolus injection and by the oral route. 31

32 Time of onset of action for different dosage forms Seconds Minutes Minutes to hours Several hours Days Varies 32

33 Time of onset of action for different dosage forms Seconds - IV injections Minutes IM & SC injections; buccal tablets; aerosols; gases Minutes to hours Short-term depot injections, solutions, suspensions Powders, granules, capsules, tablets, MR tablets Several hours - EC formulations Days Depot injections, implants Varies topical preparations 33

34 Blood level curves of nitroglycerin following administration of dosage forms by various routes 34

35 For a given drug, bioavailability may vary if: Same route but different dosage form All oral route 35

36 For a given drug, bioavailability may vary if: Same route and same type of dosage form but different formulations oral aqueous suspensions 36

37 Three different formulations of the same drug administered in equal single doses by the same non-parenteral route. 37

38 Why Biopharmaceutics is important? 38

39 Dosage Form Design Therapeutic Consideration Dosage Form Design Biopharmaceutical Consideration Drug 39

40 Rational Drug Design Biopharmaceutics allows for rational drug design: Physicochemical properties of the drug Route of administration: anatomic and physiologic Desired pharmacodynamic effect (immediate or prolonged) Toxicity profile of the drug Safety of excipients Effects of dosage form and excipients on the drug delivery. 40

41 Rational Drug Design Choosing the route of administration carefully and designing the drug product properly: Rapid and complete Slow and sustained No Absorption A B S O R P T IO N 41

42 Dose & Frequency Dosage regimen Determined from biopharmaceutical consideration 42

43 Poor biopharmaceutical properties 1. Poor and variable bioavailability 2. Difficulties with bioequivalence of formulations 3. Multiple daily dosing 4. Requirement for a non-conventional delivery system 5. Long and costly development times 43

44 Further Readings Aulton, M. E. and K. M. Taylor (2013). Aulton's pharmaceutics: the design and manufacture of medicines, Elsevier Health Sciences. Shargel, L., S. Wu-Pong and A. B. Yu (2007). Applied biopharmaceutics & pharmacokinetics, McGraw-Hill. 44

45 Thank You 45