Undergraduate - UnitPSC1032 - Physical chemistry II

Students will develop an:

1. Understanding of the physicochemical principles that underpin the important processes of pharmaceutical solids dissolving to form a solution. In particular an understanding of dissolution, solubility and distribution are critical in many areas of pharmacy and pharmaceutical science;
2. Understanding of the physical chemistry of solutions once formed will be gained through this unit, including the influence of ionizable functional groups and structure on solution behaviour;
3. Understanding of the behaviour of surface active agents at interfaces and in solution, and how micelles can improve drug solubilization;
4. Understand the physicochemical principles behind the formulation of liquid products, including one and two phase liquid systems;
5. Understanding of the behaviour and properties of pharmaceutical solids and semisolids;
6. Understanding of rheological concepts for fluids;
7. Understanding of the role and effect of components (excipients) used to produce solution based dose forms in the pharmacy field;
8. Ability to undertake calculations concerning the physico-chemical properties of drug solutions;
9. Ability to measure fundamental solution properties through practical exercises.

At the end of this unit students will be expected to:

• Describe the various forms of pharmaceutical solids and their impact on drug solution properties
• Describe the properties of polymers in solution and their rheological aspects
• Be able to calculate various rheological properties
• Describe the differences between the terms solution, supersaturation, solubility, solubility parameter, dissolution, distribution (in a physical chemistry sense) and partitioning
• Describe the factors that influence ideal and non-ideal solubility
• Describe strategies typically used to improve drug solubility
• Describe the impact of ionization on partitioning
• Outline the theories for prediction of drug solubility from solid state properties
• Calculate changes in solubility with pH for ionisable compounds
• Calculate and express solution concentrations in molarity, molality, mol fraction and equivalents
• Describe the physical chemical concepts of solutions of non-electrolytes in terms of vapour pressure, Raoult's Law and Henry's Law
• Describe the physical chemical concepts of solutions of electrolytes in terms of molar conductivity, Kolrausch's Law, activity and ionic strength
• Use Kolrausch's Law to calculate molar conductivities using the van't Hoff Factor Calculate partial pressures for ideal and non-ideal systems given concentrations and activity coefficients. Calculate ionic strength using activity coefficients, Debye Huckel approximation and the extended Debye Huckel theory
• Outline the common colligative properties and perform simple calculations to quantify these properties
• Describe the meaning and importance of isotonicity in pharmacy, and perform simple calculations of isotonicity. Describe methods of determination of tonicity of pharmaceutical solutions
• Describe each component of Fick's first law of diffusion in relation to drug transport across biological membranes
• Calculate the percentage of ionized and unionized species of an ionizable drug molecule at different pH values and describe the impact of such pH changes on overall drug absorption across a biological membrane
• Describe the behaviour of surface active molecules at interfaces
• Describe the different classes of surface active molecules and their effect on surface tension
• Describe the location and behaviour of surface active molecules in multiphase systems, particularly emulsions
• Calculate hydrophilic-lipophilic balance, and quantities of surfactants required to form emulsions of a required HLB value.