Physical Pharmacy lab Lab no 1 Concentration Expression

Physical Pharmacy lab Lab no. 1: Concentration Expression Done By: Assistant Lecturer Sura Zuhair Assistant Lecturer Hiba Sabah Assistant Lecturer Zeina Dawoad

Introduction Physical pharmacy and biopharmaceutics is the study of the relationship between the physical chemical and biological properties and the fate of a drug in vivo, The term “physical pharmacy” stems from the application of physical chemistry principles to the area of pharmacy in the design of drug molecules and drug products. Pharmacy is an applied science, composed of principles and methods borrowed from basic sciences such as physics, quantum mechanics, thermodynamics, ionization, equilibrium, chemical stability, kinetics, diffusion, permeation, adsorption and complexation. These principles allow pharmaceutical scientists to better predict quantitatively the solubility, stability, compatibility, manufacturability of drugs, and dissolution, absorption, distribution, metabolism, and elimination of drug products. When the physical chemical and biological properties of drug molecules (i. e. preformulation) are understood, it is possible to design dosage forms for designated routes of administration in humans or animals (i. e. , formulation). Collectively, the scientific principles applied in the preformulation and formulation processes is termed “physical pharmacy, ” Lab for this course: Concentration expression, Two component systems containing liquid phases, Three component systems, The tie – line for three component system, Partition coefficient, Buffer solutions and Solubility product constant for slightly soluble salt 2

Pharmaceutical mixtures True solution (<1 nm) (one phase system) Coarse dispersion (> 500 nm )( as emulsion and suspension) Colloidal dispersion (1 -500 nm ) (as liposome, microsphere) 3

Ø Dispersion : - is pharmaceutical mixture that consist of at least 2 phases with on or more dispersed (internal phase )contained in a single continuous (external )phase. Ø Phase : -is defined as the homogeneous physically distinct portion of the system separated from other parts of the system by bounding surface. 4

True solution will be focused and discussed in this lab. It can be classified according to the states in which the solute and solvent occur, and because 3 states of matter exist, 9 types of homogeneous mixtures of solute and solvent are possible. “ 5

Types of Solutions 6

Concentration expressions 7

Disadvantages of molarity & normality: 1 -changing in value with temperature because Of expansion or contraction of liquid so can not be use when studying properties of solution at various temp. 2 -because Solvent volume in M&N are not really known it is difficult to study properties such as vapor pressure & osmotic pressure which are related to the conc. Of solvent. (because Molality (m) has not the above disadvantages it is used more likely in theoretical studies more than N & M) 8

Experimental work: Materials and equipment: -Na. Cl, Na 2 CO 3. , Na. OH, Alcohol, water. -Volumetric flasks (50 cc), pipettes. Prepare the following solution : ▰ ▰ ▰ ▰ A. 50 ml of 0. 5 M Na. Cl. B. 50 ml of 2 N Na. Cl. C. 50 ml of 0. 1 N Na 2 CO 3. D. 50 ml of 0. 1 M Na 2 CO 3. E. 50 gm of 2% w/w Na. Cl solution. F. 50 ml of 10% w/v Na. OH or Na. Cl. G. 50 ml of 10% v/v alcohol. 9

Note: density or specific gravity = weight or mass / volume. Normality(N) = Molarity(M) x number of equivalents 10

USE CHARTS TO EXPLAIN YOUR IDEAS Ex: How many grams of Na. Cl will be needed to make 1. 50 Liters of an aqueous 0. 500 M solution? Answer: The equation for Molarity must be rearranged to solve for the moles of solute (Na. Cl). The moles of solute can then be converted into grams. Now, convert the moles of solute into grams by using the molar mass of Na. Cl. Na= 22. 99 g/mol , Cl= 35. 45 g/mol Na. Cl= 58. 44 g/mol Gram of Na. Cl = 0. 750 mols × 58. 44 g/mol Grams of Na. Cl= 43. 8 g 11

Thank you 12