Physical Pharmacy Unit 1 Lecture Notes PDF

Physical Pharmacy UNIT I Joe Tambis, RPh 01. 02. Units and dimensions Atoms matter With significant figures A brief recap 03. 04. Density and Specific Expressions of Gravity concentration...

Physical Pharmacy UNIT I Joe Tambis, RPh 01. 02. Units and dimensions Atoms matter With significant figures A brief recap 03. 04. Density and Specific Expressions of Gravity concentration Molarity, Molality, Normality Mole Fraction Percentage strength Eq. weights and mEqs Osmolarity and Osmolality  Physical Pharmacy -Application of physical and chemical principles and laws in the pharmaceutical sciences -To understand and develop dosage forms and drug delivery systems  “Do not panic.” —Someone Famous 01. Units and Dimensions  Measuring Stuff Quantity Dimension SI Unit Symbol Formula Base Units: Length L meter m Mass M kilogram kg Temperature Θ kelvin kg Time T second s  Quantity Dimension SI Unit Symbol Formula Derived units: Measuring Stuff Area square meter m2 Volume cubic meter m3 Velocity meter per second m/s Acceleration meter per second squared m/s2 Density kilogram per cubic meter kg/m3 Force newton N kg.m/s2 Pressure, Stress pascal Pa N/m2 Energy joule J N.m Quantity of heat joule J N.m Work joule J N.m Power watt W J/s Viscosity, dynamic pascal-second Pa.s Viscosity, kinematic square meter per second m2/s Specific heat joules per kilogram-kelvin J/kg.K  Temperature and Atmospheric Pressure will always affect the physical properties of matter, therefore, it is important to record the temperature and pressure in the laboratory before experimentation.  Significant Figures All nonzero digits are significant 23294= five significant figures All initial zeros are insignificant 0.00231= three significant figures All zeros after a significant figure AND AFTER a 9.00= three significant figure decimal point are significant 9.34300= six significant figures All zeros between significant figures are 303= three significant figures significant All zeros after a significant figure AND BEFORE a 11,000.= five significant figures decimal point are significant 11,000 = two significant figures  Conversion 10 10 10 10 10 10 Milli (m) Centi (c) Deci (d) BASE Deca (D) Hecto (H) Kilo (K) -1000 -100 -10 1 +10 +100 +1000  10 10 10 10 10 10 Milli (m) Centi (c) Deci (d) BASE Deca (D) Hecto (H) Kilo (K) -1000 -100 -10 1 +10 +100 +1000 Convert 5 g/ml to kg/dL 5 minute break 02. Atoms matter  Atoms - The smallest unit of matter Consists of proton, neutron, electron Are arranged in periods in the periodic table Each collumn is a group with similar properties and almost similar charges React with each other to form molecules and new substances Has volume and mass (very important) Calculated using moles Atoms  Atoms Important atomic weights to memorize: H 1 Mg 24.31 C 12 P 30.97 N 14 S 32.96 O 16 Cl 35.45 F 19 K 39.10 Na 23 Ca 40.08 Calculate the molecular weight of the following: 1. Phosphoric acid 2. Benzene H 1 3. Sodium Acetate C 12 4. Methanol N 14 O 16 5. C8H9NO2 F 19 6. C16H19N3O5S Na 23 7. Mg 24.31 P 30.97 S 32.065 or Cl 35.45 K 39.10 Ca 40.08 5 minute break 03. Density and Specific Gravity  Density - A property of matter - The mass (M) of matter INSIDE an occupied space (aka. Volume (V)) - Greek small letter rho (ρ) Density  Density -3 methods using the same principle of “fluid displacement” - Pycnometer method - Mohr-Westphal Balance - Plummet Method  Specific Gravity -Same method of calculation as density but NO UNIT!  Specific Volume -Opposite of density -RECIPROCAL of specific gravity - ml/g 1. If 150 ml of a sorbitol solution weighs 170g at 25⁰C, what is its density and specific gravity? 2. You receive a Rx for the following prescription, you know how to weigh solids on a balance but do not know how to weigh liquids, how much glycerin (liq), in ml, is needed to fill the Rx. The specific gravity of glycerine is 1.25. Gelatin 43.4g Glycerine (liq) 200g Pur. H2O qs 21ml  Dismissed Read up on Expressions of concentration: -Molarity -Molality -Normality -Mole fraction -Percentage Strength -Eq. weights -Milliequivalents -Osmolarity -Osmolality 04. Expressions of Concentrations Expression of Concentrations (Conc) Percentage Laboratory Conc. Strengths Molarity, molality, normality Osmolarity and Equivalent Weights Osmolality  Concentration The amount of chemical in a solvent or solution  Laboratory Concentrations Molarity Molality Normality Moles solute in 1L Moles solute in 1000g Gram equivalent weights SOLUTION SOLVENT of solute in 1L solution  What are moles? Moles is the unit of counting atoms or molecules 1 mole is 6.022 × 10²³ units (piraso) of SOMETHING (atoms or molecules) So, 1 mole of H20 is 6.022 × 10²³ units of H20 molecules Similarly, 1 mole of Sulfur, or Helium, or Actinium (whatever) is the same as 6.022 × 10²³ units of S, He, or AC atoms. What are moles?  Seatwork 1. How many moles of ethanol are in 20g ethanol? 2. How much Acetic acid (in mg) are equivalent to 4 moles of acetic acid?  Molarity (M) Moles (6.022 × 10²³ units) of solute in 1L of solution. Because volume is a variable, the result is affected by temperature. Formula: Eg. What is the molarity of 3g H2SO4 in dissolved in water to make a final solution of 425ml?  Seatwork 1. An aqueous soln of KNO3 is prepared by dissolving 80.2g of KNO3 in enough water to yield a final soln volume of 1.500L. What is the molarity if the prepared KNO3 soln? 7 minute break  Molality Moles of solute in 1kg of solvent. This value is not affected by temperature therefore is a better unit for concentration compared to the M. Formula: Eg. What is the molality of 3g H2SO4 in dissolved in 425ml water?  Seatwork 1. What is the molality of a soln with 0.025 kg NaCl in 3L of water?  Normality Equivalent weights (EW) in grams solute in 1L solution. Formula: or  Normality First: No of equivalents— # of H released by acids, or # OH released by bases, or # of e- pair accepted by metals/ donated by nonmetals, or # of e- released/accepted in redox reactions. Eg. H2SO4 (2H= 2 equivalents) Ag + HNO3 (Ag has 1 equivalent due to accepting 1 e- pair from HNO3)  Normality Second: EW—moles x number of equivalents Eg. Na2CO3 + 2HCl 🡪 H2CO3 + 2NaCl If we are looking for the EW of Na2CO3, moles x number of equivalents = 1 mol x 2 = 2g Equivalents  Normality Therefore: To solve N: or If the given is in weight, Calculate moles EW Number of equivalents Normality If the given is in M, use the second formula  Seatwork 1. What is the normality of 0.1381 M NaOh? 2. What is the normality of 0.0521 M H3PO4?  Seatwork 1. Calculate the normality of the solution obtained by dissolving 0.321 g of the salt sodium carbonate (Na2CO3) in 250 mL water. 7 minute break  Mole Fraction The parts (in moles) of components in a solution. Formula: Eg. What are the mole fractions of 2g NaCl in 100ml water? 1. Get total moles of NaCl and Water. 2. Calculate using formula, once for each chemical Percentage Strength  Percentage Strength Concentration of solute in solution in % w/w, % v/v, %w/v Formula:  Seatwork 1. Find the % concentration (g/ml) of 0.9g NaCl in 100ml soln. 2. Find the % concentration (g/ml) of 2.0g sugar in 50ml soln. 3. Find the % concentration (w/w, g/g) of 5.2g glycerin in 10g PEG 4000. 4. Find the % concentration (w/w, g/g) of 0.423 kg Atropine sulfate in cocoa butter making a total weight of 1.0 kg. 7 minute break  Milliequivalents An equivalent is the amount of a substance that will react with a certain number of hydrogen ions. A milliequivalent is one-thousandth of an equivalent.. Formula: Eg. The patient is to take 40 mEq of potassium in the form of potassium chloride solution. How many milligrams of potassium does this represent?  Osmolarity An osmole is an amount of a substance that contributes to the osmotic pressure of a solution. A milliosmole is one-thousandth of an osmole. Formula: 1. For nonelectrolytes 2. For strong electrolytes 3. For any ion  Seatwork 1. Find the % concentration (g/ml) of 0.9g NaCl in 100ml soln. 2. Find the % concentration (g/ml) of 2.0g sugar in 50ml soln. 3. Find the % concentration (w/w, g/g) of 5.2g glycerin in 10g PEG 4000. 4. Find the % concentration (w/w, g/g) of 0.423 kg Atropine sulfate in cocoa butter making a total weight of 1.0 kg.  Dismissed Read up on: - Forces of attraction - States of matter