THESE DRUGS REACT TO STRONG ACIDS TO ALKALIS TO FORM WATER-SOLUBLE SALTS.WEAK BASES – ALKALOIDS (MORPHINE ATROPINE, CODEINE). ANTIHISTAMINES ( DIPHENHYDRAMINE, PROMETHAZINE). LOCAL ANESTHETICS (COCAINE, PROCAINE, TETRACAINE)
Obtained by Distillation; Ion exchange treatment; Reverse Osmosis
ALUMINUM ACETATE (BURROW’S SOLUTION)–ASTRINGENT WASH AND WET DRESSINGCALCIUM HYDROXIDE LIQUOR CALCIS) – TOPICAL ASTRINGENT IN CALAMINE LOTIONHYDROGEN PEROXIDE – LOCAL ANTI-INFECTIVE CHLORHEXIDINE GLUCONATE – ANTIMICROBIAL FOR DENTAL PLAQUE AND GINGIVITISPOVIDONE IODINE – SURGICAL SCRUBSTRONG IODINE (LUGOL’S) – ANTI- INFECTIVE
Chap 13 part 1 solutions
Presented by:Asst. Prof. Ma. Lourdes L. Mojares, R. Ph.CEU School of PharmacyManila
SOLUTIONS: DEFINITION Liquid preparations that contain one or more chemical substances dissolved in a suitable solvent or mixture of (mutually miscible) solvents. It may be oral, otic, opthalmic or topical.
SOLUBILITYFACTORS AFFECTING SOLUBILITY1. Temperature2. Chemical and physical properties of the solute and the solvent3. Pressure4. pH of the solution5. State of subdivision of the solute6. Physical agitation applied to the solution as it dissolves
1. Effect of Temperature Chemicals with Positive Heat of Solution The kind that absorbs heat when dissolved. It results to an increased solubility with an increase in temperature.
1. Effect of Temperature Chemicals with Negative Heat of Solution The kind that releases heat when dissolved. It results to an decreased solubility with an increase in temperature.
2. Effect of PhysicochemicalProperties (pressure, temperature) of the solute and solvent The solubility of a “pure” chemical substance at a given temperature and pressure is constant.
3. State of subdivision of the solute (particle size) The “finer” the powder, the greater the surface area that comes in contact with the solvent. Therefore, the more rapid the dissolving process.
4. Physical Agitation Applied to the Solution As It Dissolves The greater the agitation, the more unsaturated solvent passes over the drug. Therefore, the faster the formation of a solution.
5. Effect of pH of the Solution Many important organic medicinal agents are either “weak acids” or “weak bases.” Drugs as weak bases are not very water-soluble, but are soluble in dilute solutions of acids.
5. Effect of pH of the Solution Drugs as weak acids form water- soluble salts in basic solutions. These drugs may separate from the solution by lowering the pH of the solvent system.
Techniques to hasten dissolution Application of heat Reduction of particle size of the solute Use a solubilizingagent Subject the ingredients to vigorous agitation
1. ALCOHOL, USP The most useful solvent, next to water. 94.9% to 96% C2H5OH (v/v) Miscible with water and has the ability to dissolve many water- insoluble ingredients (flavorants, preservatives). With preservative effect
2. DILUTED ALCOHOL, NF Contains equal volumes of Alcohol, USP and Purified Water, USP. 49% concentration A useful hydroalcoholic solvent.
3. RUBBING ALCOHOL Contains about 70% Ethanol v/v. Volatile and Flammable, should be stored in tight containers, remote from fire. Used externally as rubefacient, soothing rub, germicide (for instruments), skin cleanser (prior to injection), vehicle in topical preparations.
4. GLYCERIN, USP Glycerol , CH2-OH-CHOH-CH2OH Clear, viscous syrupy liquid with sweet taste Miscible to both water and alcohol
4. GLYCERIN, USP Comparable to alcohol, as solvent. Solutes are slowly soluble (requires heating) Preservative, stabilizer, auxilliary solvent with water and alcohol Used extensively in internal preparations.
5. ISOPROPYL RUBBING ALCOHOL 70% v/v isopropyl alcohol. Commercially available as 91% External Uses: rubefacient, soothing rub, vehicle for topical products.
5. ISOPROPYL RUBBING ALCOHOL Commonly employed by diabetic patients in preparing needles and syringes for hypodermic injections of insulin. Skin disinfection of diabetic patients.
6. PROPYLENE GLYCOL, USP CH3CH(OH)CH2OH Viscous liquid, miscible with water and alcohol. Useful solvent with a wide range of applications. Substitute for glycerin
6. PURIFIED WATER, USP For preparation of aqueous dosage forms, except those intended for parenteral administration. Contains 1% as much dissolved solids as tap water
TYPES OF SOLUTIONSAs to its use: As to composition1. Oral solutions Aromatic waters2. Topical solutions Syrups3. Ophthalmic Elixirs solutions Spirits4. Nasal and Otic solutions Tinctures and fluidextracts Douches, Enemas and* 3 and 4 are discussed gargles in Chapter 17 Liniments, collodions, and others
1. ORAL SOLUTIONSCOMPONENTS Medicinal agents Flavorants, Colorants and Sweetening agents Stabilizers (glycerin or sorbitol) – used to inhibit crystallization and to modify solubility Preservatives (parabens) Vehicles
ORAL SOLUTIONSADVANTAGES DISADVANTAGES1. Homogenous 1. Bulky2. Easier to swallow than 2. Degrade more the solid dosage forms rapidly3. Onset of action and 3. More likely to bioavailability of interact with other drugs that have slow constituents dissolution rate are improved
DRY POWDER FOR SOLUTIONDry powder for reconstitution prior to useExamples: Cloxacillin Na, Oxacillin Na and Penicillin VK for oral solution (antibiotics) ORAL REHYDRATION SOLUTIONAvailable in liquid or packet of powder for reconstitutionExamples: Pedialyte and Rehydrate solution, Glucolyte, Oresol ORAL COLONIC LAVAGE SOLUTION OTHERS – Magnesium citrate solution
3. OTIC SOLUTIONS Ear or aural solutionsUSES: For the removal of excessive cerumen Examples: Cerumenex Ear drop, Debrox Drops For the treatment of ear infections, inflammation, or pain Examples: AuralganOtic Solution, AmericaineOtic, ChloromycetinOtic, CorticosporinOtic, Otobiotic solution, VoSolOtic Solution
METHODS OF PREPARATION of SOLUTIONS SIMPLE SOLUTION METHODExample: Strong Iodine (Lugol’s) Solution SOLUTION BY CHEMICAL REACTIONExample: Magnesium Citrate Solution SOLUTION BY EXTRACTION
PHARMACEUTICAL SOLVENT WATERS PURIFIED WATER, USP WATER FOR INJECTION, USP STERILE WATER FOR INJECTION, USP BACTERIOSTATIC WATER FOR INJECTION, USP STERILE WATER FOR INHALATION, USP STERILE WATER FOR IRRIGATION, USP* WFI, SWFI and BWFI are discussed in Chapter 15
PURIFIED WATER, USP Obtained by: distillation, reverse osmosis or by ion exchange treatment pH 5 to 7 Contains NMT 10 ppm of total solids Used in preparations and in finished and manufactured products, except for the preparation of parenterals and ophthalmic products
WATER FOR INJECTION, USP Conforms with the standards of Purified Water, USP but is also pyrogen-free. Intended to be used in the manufacture of injectable products which are to be sterilized after their preparation. Intended to be used for 24-hours after its collection.
STERILE WATER FOR INJECTION, USP WFI that has been sterilized Packaged in single-dose containers of type I or type II glass that do not exceed the capacity of 1 liter Intended to be used as a solvent, vehicle or diluent for already-sterilized and packaged injectable medications
BACTERIOSTATIC WATER FOR INJECTION, USP SWFI that contains one or more suitable bacteriostatic agents Packaged in pre-filled syringes or in vials containing NMT 30 mL Employed as a sterile vehicle in the preparation of small volumes of injectable preparations (in multiple-dose vials) To be labeled “NOT FOR USE IN NEWBORNS”
STERILE WATER FOR IRRIGATION, USP Same requirements as SWFI except in container design, particulate matter and labeling LabelingRequirements: “ For Irrigation Only ” “ Not for Injection ”
AROMATIC WATERS Are clear, saturated aqueous solutions of volatile oils or other aromatic or volatile substances A pleasantly flavored vehicle for water soluble drugs or an aqueous phase in an emulsion or suspension
AROMATIC WATERS Addition of electrolytes may result to “salting-out” of the volatile ingredient Must be free from empyreumatic (smoke-like) odors. Stored in a tightly closed, light-resistant containers Protect from excessive heat
Methods of Preparation of Aromatic Waters DISTILLATIONCOHOBATION – the process of redistillation two or more times until the distillate becomes clear SOLUTION METHOD – the volatile, or aromatic substance is admixed with water, with or without the use of a dispersant (e.g. talc) A. Simple Solution B. Alternate Solution