Pharmaceutical Technology Lecture Notes PDF

Mazaya University College Pharmaceutical Technology I Lec. 1 Department of Pharmacy 2024-2025 Dr. Ali Aljaberi SOLUTIONS ‐In physicochemical terms, solutions may be prepared from any combination of solid,...

Mazaya University College Pharmaceutical Technology I Lec. 1 Department of Pharmacy 2024-2025 Dr. Ali Aljaberi SOLUTIONS ‐In physicochemical terms, solutions may be prepared from any combination of solid, liquid or gas, the three states of matter ‐Liquid preparations that contain one or more soluble chemical substances dissolved in a suitable solvent or mixture of mutually miscible solvents ‐Homogenous mixture that is prepared by dissolving a solid, liquid or gas in another liquid and represents a group of preparations in which the molecules of the solute or dissolved substance are dispersed. Types of Solutions 1- Solid Solution: the solvent is solid a. Solid in solid: Example: Cu + gold= 12 karat yellow gold b. Liquid in solid: Example: Hg dissolved in Ag = amalgam c. Gas in solid: Example: air dissolved in soap = floating soap 2- Liquid Solution: the solvent is liquid a. Solid in liquid: Ex: salt in water b. Liquid in liquid: Ex:andwater c. Gases in liquid: Ex: carbonated beverages 3- Gaseous Solutions: the solvent is gas a. Solid in gas: Example: sulfur in air b. Liquid in gas: Example: water vapor in air c. Gas in gas: Example: oxygenated air 1 Mazaya University College Pharmaceutical Technology I Lec. 1 Department of Pharmacy 2024-2025 Dr. Ali Aljaberi Solubility The solubility of an agent in a particular solvent indicates the maximum concentration to which a solution may be prepared with that agent and that solvent (solubility) When excess of solid (solute) is shaken with liquid (solvent) for a period of time a maximum amount of it will be dissolved (saturated solubility). When excess amount of solute is added to saturated solution and the temperature is increased more of solute will be dissolved (super saturated solution). Factors affecting the “rate” of solubility or dissolution Rate of dissolution is the speed at which the solute goes into solution, it depends on: 1. Particle size An increase in surface area to the solvent will increase rate of solution. So the particle size should be reduced by comminution before it is dissolved. 2. Agitation Increases the rate of solution by removing from the surface of the solute. The more concentrated solution around it the less concentrated the solvent. 3. Temperature Heating a liquid also causes solution to take place more rapidly by increasing the frequency which solvent molecules collide with the surface of the dissolving mixture Factors Affecting Solubility of Solute 1. Temperature Endothermic reaction: The process of solution where heat is applied and absorption of the heat takes place in the solutes, this increase in temperature will cause more of the solute to go into solution. Exothermic reaction: solute gives off heat during the process of solution; solubility is decreased with an increase in temperature. Example:more soluble in cold than hot water Methyl cellulose and calcium salts such as Ca(OH)2 2 Mazaya University College Pharmaceutical Technology I Lec. 1 Department of Pharmacy 2024-2025 Dr. Ali Aljaberi 2. Molecular Structure The general rule: “like dissolves like” 3. Effects of other substance Example:Iodine is very slightly soluble in water but when added to a concentrated solution of KI dissolves immediately. 4. pH Many of the organic substances which are used medicinally are either weak acids or weak bases. And their aqueous solubility depend upon the pH of the solvent. Examples of Weak Bases Alkaloids : atropine,codeine, morphine Antihistamines : diphenhydramine, tripelennamine Local anesthetics : cocaine, procaine, tetracaine Examples of Weak Acids Barbiturates: phenobarbital, pentobarbital Sulfonamides: sulfadiazine, sulfacetamide 3 Mazaya University College Pharmaceutical Technology I Lec. 1 Department of Pharmacy 2024-2025 Dr. Ali Aljaberi 4 Mazaya University College Pharmaceutical Technology I Lec. 1 Department of Pharmacy 2024-2025 Dr. Ali Aljaberi Inorganic Molecules 1. Monovalent cation and anionof an ionic compound are generally water soluble Examples:NaCl, LiBr, KI, NH4NO3 2. Only one of the two ions is monovalent –compounds are water soluble Examples:BaCl2, MgI2, Na2SO4, Na3PO4 3. Both ions are multivalent ‐poor water soluble. Examples:CaSO4, BaSO4, BiPO4 Exceptions:ZnSO4 and FeSO4 4. Common salts of alkali metals are usually water soluble Exception:Li2CO3 5. NH4 and quaternary NH4 salts are water soluble 6. Nitrates, Nitrites, acetates, chlorates and lactates are generally water soluble Exceptions:silver and mercurous acetate 7. Sulfates, sulfites and thiosulfates are generally water soluble Exceptions:Calcium and Barium salts 8. Chlorides, bromides and iodides are water soluble Exceptions:salts of silver and mercurous ions 9. Acid salts corresponding to an insoluble salt will be more water soluble than organic salts. 10. Hydroxides and oxides of compounds other than alkali metal cations and the ammonium ion are generally water insoluble. 11. Sulfides are water insoluble except for their alkali metal salts 12. Phosphates, carbonates, silicates, borates and hypochlorites are water insoluble except for their alkali metal salts and ammonium salts Organic Molecules 1. Molecules having 1 polar functional group –soluble to the total lengths of 5C’s 2. Molecules having branched chains are more soluble than the corresponding straight‐ chain compound. 3. Water solubility decreases with increase in MW 4. Increased structural similarity between solute and solvents accompanied by increase solubility. Solvents for Liquid Preparations 1. Water: has the widest range of usefulness of all the solvents employed in pharmaceutical dispensing or manufacturing. It is a good solvent for most inorganic and organic 5 Mazaya University College Pharmaceutical Technology I Lec. 1 Department of Pharmacy 2024-2025 Dr. Ali Aljaberi 2. Alcohol USP, Ethyl Alcohol, Ethanol: good solvent for many organic substances both natural and synthetic. Is 94.9 to 96.0% alcohol at 15.560C. Limit:0.5% = 6 to 12 years, 5% = over 12, 10% = adult 3. Dehydrated Alcohol: 99.5% absolute alcohol is partially free from water. 4. Diluted Alcohol NF: prepared by mixing equal volume of Alcohol USP and purified water. 5. Alcohol, Rubbing: contains about 70% of ethyl alcohol by volume the remainder consists of water, denaturants with or without color additives and perfume oils and stabilizers. 6. Glycerin USP ( Glycerol): clear syrupy liquid with sweet taste. It is miscible both with water and alcohol. Excellent solvent for tannins, phenol and boric acid. It has a preservative qualities. 7. Propylene Glycol: miscible in water, acetone, alcohol and chloroform 8. Polyethylene glycol 400: miscible in water, acetone alcohol and other glycols 9. Chloroform: miscible with alcohol, ether, benzene, hexane and both fixed and volatile oils 10. Acetone: miscible with water, alcohol, ether, chloroform and most of the volatile oils. 6