Physical Pharmaceutics II

Solutions, Solubility, solubilization and dissolution (definition and differentiation). Factors affecting solubility and rate of dissolution; Solutions of liquids in liquids. Solvents for pharmaceutical aerosols.  Colligative properties of solutions. Phase equilibra, phase rule; Systems of one and two components and applications in pharmacy, e.g., eutectic mixture. Distribution of drugs between two immiscible solvents and their applications in pharmacy. Diffusion; Concept and importance in living systems. Factors affecting diffusion. Diffusion of drugs in solutions and through tissues. Adsorption: Definition, types and mechanism of adsorption: Adsorption theories; Langmuir and Freundlich isotherms, Factors affecting adsorption; application of adsorption in pharmacy and medicine. Surface and Interfacial Phenomena: Surface tension: contact angle and the wetting of solids, spreading of one liquid over another, mechanism of capillary rise and effect of temperature, method of determining surface tension. Surface active agents and their classification: pharmaceutical applications and medicinal importance of surface active agents. Bulk Properties of Surfactant Solutions: micelle and critical micelle concentration (CMC); factors affecting stability of micelles.  Colloidal systems: classification of colloids; properties of colloidal solutions; preparation and stability of lyophobic colloids Rheology: Newtonian fluids; flow characteristics of Newtonian fluids and effect of temperature; determination of viscosity – principles of capillary tube; Redwood and falling sphere viscometers; rotational viscometers; the flow properties of disperse systems and viscosity coefficients of colloidal dispersions; viscosity imparting agents in pharmacy; non-Newtonian fluids; plastic, pseudoplastic and dilatant flows; thixotropic systems; rheological properties of suspensions; emulsions, ointments and creams. Biorehology. Mechanism of fluid flow; significance of Reynolds number; distribution of velocities across a tube and boundary layers. Pharmaceutical mass transport e.g. diffusion and dialysis, etc. Biopharmaceutical and pharmacokinetic considerations in dosage forms design. Salt selection in dosage form design and development. Selection of additives. Taste masking. Introductory pharmaceutical material science. Characterization of pharmaceutical raw materials.