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41 Cards in this Set
- Front
- Back
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what is a solution?
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liquid preparations that contain one or more chemical substances dissolved in a suitable solvent or a mixture of mutually miscible solvents
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5 types of solutions based on composition
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1)Syrup
2)Elixir 3)Spirits 4)Aromatic Washes 5)Tinctures/Fluid Extracts |
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What must occur for salvation to occur?
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when a solute dissolves, the substance's intermolecular forces of attraction must be overcome by forces of attraction between the solute and solvent molecules
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What does the solubility of an agent in a particular solvent indicate?
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the maximum concentration to which a solution may be prepared with that agent and that solvent
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How is a solute's solubility expressed?
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Very Soluble, Freely Soluble, Soluble, Sparingly Soluble, Slightly soluble, very slightly soluble, practically insoluble/insoluble.
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Which solvent would have a higher concentration in the same quantity, one with a freely soluble solute or a slightly soluble solute?
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The one with a freely soluble solute because it takes less parts of solvent to dissolve the solute
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What are many important organic medicinal agents and how do they dissolve?
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-either weak acids or weak bases
-Dissolve by forming acid salts or base salts enabling the preparation of aqueous solutions ex)weak acids are soluble in weak bases... |
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Examples of weak bases and their salts
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-Atropine
-Atropine sulfate -Codeine -Codeine Sulfate -Codeine Phosphate -Morphine -Morphine Sulfate |
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How does the weak acid/base being a salt or not effect its solubility in water and alcohol?
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Salts of the weak acids/bases require much less water to dissolve or more alcohol to dissolve
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Examples of weak acids and their salts
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-Phenobarbital
-Phenobarbital Sodium -Sulfadiazine -Sodium Sulfadiazine |
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What does it mean if a solute requires more alcohol to dissolve it in a solution?
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solution is lipophilic
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What are 4 common pharmaceutical solvents?
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-Water
-Alcohol -Glycols -Syrups |
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Why is tap water not a good solvent?
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-contains <0.1% solids
-contains many ions that can form insoluble complexes, which are non absorbable -may not reach therapeutic concentration in blood |
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How is purified water USP formed?
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-Distillation: heat and maintenance increase cost
-Ion-Exchange: run tap through column of cation and anion exchange resins -Reverse Osmosis: uses membrane which can remove pathogens, sometimes combined with ion-exchange |
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What are FDA restrictions on using alcohol USP in solutions?
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<6 yrs = 0.5% alcohol
6-12 yrs = 5.0% alcohol >12 yrs = 10.0% alcohol |
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Describe alcohol USP / ethyl alcohol
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-94.9-96.0% ethyl alcohol
-miscible with water and forms a hydroalcoholic mixture |
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Describe rubbing alcohol and what it is used for
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-about 70% ethyl alcohol
-used as a rubefacient (increases blood flow), soothing rub, skin cleanser, and as a vehicle for topical products |
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What is the denaturant of rubbing alcohol?
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- 8 parts acetone
-1.5 parts methyl isobutyl ketone -100 parts ethanol |
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Describe isopropyl rubbing alcohol
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-70% by volume is isopropyl alcohol
-used externally as rubefacient, soothing rub, and vehicle -No infant/child use |
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Describe the use of Propylene Glycol as a solvent
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-miscible with water and alcohol
-widely used for solubilizing lipophilic drugs -some preservative properties -included in many parenteral preparations |
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Describe the use of glycerin as a solvent
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-clear, syrupy liquid with sweet taste
-miscible with water and alcohol -comparable to alcohol, but solutes dissolve much slower -preservative qualities |
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What is a syrup?
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concentrated aqueous preparation of a sugar or sugar-substitute with or without flavoring agents and medicinal substances
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What are the components of a syrup?
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-purified water
-sugar or sugar substitute -preservative -flavorant -colorant |
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What are common sugars and sugar substitutes used in syrups?
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-Sucrose (60-80%) most common
-sorbitol for diabetics, glycerin, and propylene glycol -may also use celluloses |
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What are common preservatives in syrups? what does their concentration depend on?
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-Benzoic Acid (0.1-0.2%)
-Sodium Benzoate (0.1-0.2%) -Methyl, Propyl and Butyl Parabens (0.1%) -concentration in solution depends on water availability, more available water = more preservative needed |
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How can syrups be prepared using heat?
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1)sugar added to purified water until dissolved
2)heat stable components added to hot syrup 3)let cool 4)adjust volume with purified water |
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Why should you use caution when preparing syrups with heat?
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-excessive heat hydrolyzes sucrose, a disaccharide, into monosaccharides dextrose and fructose
- forms an invert sugar which is sweeter than sucrose -the colorless syrup darkens in color |
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How can syrups be prepared without heat?
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-by agitation
-sucrose and other agents dissolved in purified water by placing ingredients in vessel larger than the volume of syrup to be made and permitting thorough agitation to mixture -more time consuming, but ensures stability |
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What is an Elixir? compare to a syrup
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-clear, sweetened hydroalcoholic solutions for oral use
-less sweet and viscous than syrups because less sugar -better at solubilizing components because of hydroalcoholic nature |
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How do Elixirs need to be preserved?
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-those with >15% alcohol are self preserving
-need to be stored in airtight, light-resistance containers |
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How are elixirs prepared?
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1) usually by simple solution with agitation and/or by admixture of 2 or more liquid ingredients
-Alcohol soluble and water soluble components dissolved separately in alcohol and purified water. -aqueous solution added to alcohol solution to maintain highest possible alcohol strength. |
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What are spirits?
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alcoholic or hydroalcoholic solutions of volatile or aromatic substances
->60% alcohol content, highest alcohol contents -active ingredient may be solid, liquid, or gas |
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Name 2 examples of spirits and what they taste like
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-Spiritus Vini Vitis: brandy
-Spiritus Frumenti: whiskey |
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What are aromatic waters?
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-clear, aqueous solutions saturated with volatile oils or other aromatic volatile substances
-not used much anymore |
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What are aromatic waters used for and how must they be stored?
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-used primarily as flavored or perfumed vehicles
-unstable so must be stored in airtight, light-resistant containers |
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What are Tinctures?
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-alcoholic or hydroalcoholic solutions prepared from vegetable materials or from chemical substances like iodine
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Why can tinctures not be diluted with more than 15-80% alcohol?
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because solute may precipitate out
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What is an Extract?
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-concentrated preparation of vegetable or animal drugs
-after removal of active ingredients, solvent is evaporated and the active ingredient reconstituted to desired strength |
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2 main methods of preparing solutions?
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Maceration - to soak
Perculation - to strain |
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What is a douche?
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-aqueous solution directed against a part or into a body cavity
-frequently dispensed as a powder with directions for dissolving |
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What are the 2 types of enemas?
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Evacuation: used to evacuate the bowel
Retention: influence general system by absorption or to affect locally the site of disease |
