About Physical Pharmaceutics II
Subject Code
BP403T
Semester
Semester 4
Credits
4 Credits
Physical Pharmaceutics II (BP403T) explores the physical and chemical principles underlying dosage form design. Topics include the properties of dispersed systems (colloids, suspensions, emulsions), the flow behaviors of liquids (rheology), powder characteristics (micromeritics), and the kinetics of drug degradation and stability.
Key Learning Objectives
- Understand Dispersions: Learn the properties, formulation, and stability of colloidal and coarse dispersions.
- Master Rheology: Study Newtonian and non-Newtonian flow, and methods of viscosity determination.
- Analyze Powders: Understand micromeritics, including particle size, surface area, and powder flow properties.
- Study Reaction Kinetics: Learn the kinetics of drug degradation and methods for stability testing.
Syllabus & Topics Covered
Unit 1: Colloidal Dispersions
- Classification of dispersed systems & general characteristics
- Size, shapes, and properties of colloids (Optical, Kinetic, Electrical)
- Effect of electrolytes, Coacervation, Peptization & Protective action
Unit 2: Rheology & Deformation of Solids
- Newtonian systems, kinematic viscosity, effect of temperature
- Non-Newtonian systems (pseudoplastic, dilatant, plastic, thixotropy)
- Determination of viscosity (capillary, falling sphere, rotational viscometers)
- Plastic and elastic deformation, Heckel equation
Unit 3: Coarse Dispersions (Suspensions & Emulsions)
- Interfacial properties of suspended particles, settling, flocculation vs deflocculation
- Emulsions and theories of emulsification, Microemulsion
- Stability, preservation, and formulation of emulsions by HLB method
Unit 4: Micromeritics
- Particle size and distribution, methods of determining particle size
- Specific surface area and methods of determination
- Derived properties of powders (porosity, packing arrangement, densities, flow properties)
Unit 5: Drug Stability
- Reaction kinetics: zero, pseudo-zero, first & second order
- Physical and chemical factors influencing drug degradation
- Stabilization against hydrolysis and oxidation; Accelerated stability testing
How to Score High in Physical Pharmaceutics II
- 1
Understand the Physics: Topics like rheology and micromeritics are heavily physics-based. Try to understand the underlying laws (like Stokes’ Law) clearly.
- 2
Graphs are Important: Practice drawing rheograms for different types of non-Newtonian flow.
- 3
Differentiate Systems: Make comparison charts for lyophilic vs lyophobic colloids, and flocculated vs deflocculated suspensions.
- 4
Solve Numericals: Practice numerical problems on reaction kinetics, half-life, and expiration dating (Unit 5).
Why it Matters for Career
These principles are fundamental to formulation development in the pharmaceutical industry. Understanding powder flow (micromeritics) is crucial for tablet manufacturing, while rheology is essential for formulating creams, lotions, and injectables.
Exam Weightage
Rheograms, derivation of kinetic equations, working of different viscometers, and the formulation of stable suspensions and emulsions are highly emphasized in university exams.
Frequently Asked Questions (FAQs)
Are numerical problems asked in the exam?
Yes, simple numerical problems from drug stability (half-life, shelf-life based on first-order kinetics) and occasionally from micromeritics are common.
What is thixotropy?
It is an isothermal and comparatively slow recovery, on standing of a material, of a consistency lost through shearing. It is highly desirable in suspensions.
Why is accelerated stability testing done?
To predict the shelf life of a drug product rapidly by exposing it to exaggerated storage conditions like elevated temperature and humidity.