Unit 1345: Biopharmaceutics and Drug Delivery

1. Introduction to Biopharmaceutics

• Definition and scope of biopharmaceutics
• Importance in pharmaceutical sciences
• Relationship with pharmacokinetics and pharmacodynamics
• Historical development and current trends

2. Drug Absorption

2.1 Mechanisms of Drug Absorption

• Passive diffusion
• Facilitated diffusion
• Active transport
• Endocytosis

2.2 Factors Affecting Absorption

• Physiological factors (e.g., GI tract pH, motility)
• Physicochemical properties of drugs (solubility, stability)
• Formulation factors

2.3 Routes of Drug Administration

• Oral
• Sublingual and buccal
• Rectal
• Parenteral
• Transdermal
• Inhalation

3. Drug Distribution

3.1 Principles of Drug Distribution

• Role of blood circulation
• Tissue permeability and barriers (e.g., blood-brain barrier)
• Volume of distribution

3.2 Protein Binding

• Plasma proteins involved (albumin, alpha-1 acid glycoprotein)
• Impact on free drug concentration and activity

3.3 Factors Influencing Distribution

• Age, disease state
• Drug properties

4. Drug Metabolism

4.1 Metabolic Transformation

• Phase I reactions (oxidation, reduction, hydrolysis)
• Phase II reactions (conjugation)

4.2 Enzymes Involved

• Cytochrome P450 enzyme system
• Other metabolizing enzymes

4.3 Significance of Metabolism

• Detoxification and activation of prodrugs
• Impact on drug half-life and pharmacokinetics

5. Drug Elimination

5.1 Renal Excretion

• Glomerular filtration
• Tubular secretion and reabsorption

5.2 Hepatic Metabolism and Biliary Excretion

5.3 Factors Affecting Drug Clearance

• Organ function
• Drug interactions

6. Pharmacokinetics

6.1 Overview of ADME (Absorption, Distribution, Metabolism, Elimination)

6.2 Pharmacokinetic Parameters

• Half-life
• Clearance
• Bioavailability
• Volume of distribution

6.3 Modeling Drug Concentration-Time Profiles

7. Bioavailability

7.1 Definition and Importance

7.2 Measurement of Bioavailability

• Area under the curve (AUC)
• Peak plasma concentration (Cmax)
• Time to peak concentration (Tmax)

7.3 Factors Affecting Bioavailability

• Formulation
• First-pass metabolism
• Physiological factors

8. Drug Delivery Systems

8.1 Oral Delivery

• Tablets, capsules, suspensions
• Advantages and limitations

8.2 Transdermal Delivery

• Patches and gels
• Skin permeability considerations

8.3 Inhalation Delivery

• Aerosols, nebulizers
• Targeting respiratory tract

8.4 Parenteral Delivery

• Intravenous, intramuscular, subcutaneous
• Sterility and formulation considerations

8.5 Impact of Delivery Systems on Therapeutic Outcomes

9. Drug Formulation and Development

9.1 Dosage Forms

• Solid, liquid, semi-solid

9.2 Excipients and Their Roles

• Binders, fillers, preservatives

9.3 Drug Stability

• Physical and chemical stability
• Shelf life considerations

9.4 Factors Influencing Formulation Design

• Drug properties
• Target site and release profile

10. Regulatory Aspects in Biopharmaceutics

10.1 Drug Approval Processes

• Preclinical and clinical requirements

10.2 Bioequivalence Studies

• Design and interpretation

10.3 Quality Control Measures

• Good Manufacturing Practices (GMP)
• Analytical testing

10.4 Safety and Efficacy Considerations