Solutions -- ORAL (pt 2) Flashcards
name 4 factors used to enhance the DISSOLUTION PROCESS
-heat (ASIDE FROM Calcium Hydroxide Topical Solution, USP)
-reduce particle size of the solute
-utilize a solubilizing agent
-rigorous agitation
Liquid drugs taken orally can either be ___ or ___
dry mixtures for solution (requiring compounding) or oral solutions (ready for use)
Why so dry mixtures for solution exist? why can’t all liquid oral dosage forms just exist as ready to use solutions?
medications come as dry mixtures that require compounding because they have insufficient stability in aqueous solutions.
making them as dry mixtures increases their shelf life
Give 4 examples of oral solutions (NOT dry mixtures. oral solutions are the ones that are ready to use and dont need compounding)
-oral rehydration solutions
-oral colonic lavage solution
-Magnesium citrate oral solution
-Sodium citrate and citric acid oral solution
When are oral rehydration solutions used?
in cases of rapid fluid loss to make up for the lost water
for example, diarrhea.
often used in pediatrics.
name 4 commercial products that are oral rehydration solutions
-Resol solution
-Pedialyte solution
-Rehydrate solution
-Ricelyte oral solution
Oral Colonic Lavage Solutions are used for….
Colonoscopy. These solutions are oral laxatives
name 2 oral laxatives that used to be used all of the time for colonoscopy prep, but arent used as much anymore and explain why
magnesium citrate and bisacodyl (ducolax)
these 2 have systemic effects that can cause unpleasant side effects such as vomiting. the drug gets into systemic circulation
what is an alternative method to magnesium citrate/bisacodyl?
PEG-3350-Electrolyte solution
contains:
Polyethylene glycol (PEG) 3350
sodium sulfate
sodium bicarbonate
sodium chloride
potassium chloride
in 4000 mL disposable container
THIS IS AN ADVANTAGE over the other 2, because the effects are purely local and not systemic
what is a cathartic?
accelerates defecation
give an example of a cathartic (PRODUCT)
Magnesium Citrate Oral Solution
which product requires a chemical reaction to make it? what is the basis of the reaction?
Magnesium Citrate Oral Solution
magnesium carbonate reacts with excess of citric acid. solution may be further carbonated by carbon dioxide
what is the name of the product involved in maintaining the alkaline urine?
Sodium Citrate & Citric Acid Oral Solution
Sodium Citrate & Citric Acid Oral Solution is known as a ___ ___
Systemic alkalinizer
If a drug is in ionized form, will it stay in the urine or be reabsorbed back into circulation?
what about a drug in unionized form?
ionized – it will stay in the urine
unionized – it will be reabsorbed back into circulation
explain in more detail the function of Sodium Citrate & Citric Acid Oral Solution
systemic alkalinizer. controls pH in the urine to avoid reabsorption (avoid reabsorption = ionized form)
give the definition of a syrup
a syrup is a concentrated or nearly saturated aqueous solution of sugar
name 2 classes of syrups
nonmedicated syrups – for compounding
medicated syrups – in the market. contain sugar AND the API
give examples of nonmedicated syrups (PRODUCTS)
Cherry Syrup
Cocoa Syrup
Orange Syrup
Ora-Sweet
Ora-Sweet SF
Syrup
Medicated Syrups are mostly for which population?
children and elderly people
name the components of syrups
-sugar (sucrose) or sugar-substitutes
-antimicrobial preservatives
-flavorants
-colorants
-others (ie: special solvents such as alcohol to dissolve the API, solubilizing agents, thickeners, or stabilizers)
What are glycogenetic substances? explain and give examples
Glycogenetic substances convert to GLUCOSE in the body.
examples are sugars (sucrose and dextrose)
and nonsugars (sorbitol, glycerin, PPG)
Explain what Non-Glycogenetic substances are and give examples
Non-Glycogenetic substances do NOT undergo hydrolysis and absorption into circulation (NOT converted to glucose)
examples: methylcellulose, hydroxyethylcellulose
preferred for diabetic patients
Name the components of Syrup, NF and the other name it goes by
Syrup, NF is also known as Simple Syrup
it contains 85 g of sucrose in 100mL water (85% w/v)
it does NOT contain preservatives – low free water for microbial growth
what is the specific gravity of Syrup, NF
1.313
what is the %w/w of Syrup NF (aka Simple Syrup)
~65%
Antihistamine syrup is a total of 1000mL
Glycerin is present in 25mL of that 1000mL
What is the function of glycerin?
cosolvent
True or false
preservative is not good for the human body, so we want to use it in minimal amounts
true
A substance present in syrups in ____ amounts is most likely to indicate that it is being used as a cosolvent
SMALL
Why is both Sorbitol and Syrup used in Antihistamine Syrup?
Syrup contains 85% sucrose. Sucrose converts to dextrose very easily. Sorbitol is a nonsugar – doesnt convert to dextrose as easily – attempt to suppress the dextrose
Name 4 medicated syrups
Antihistamine Syrup
Ferrous Sulfate Syrup
Acetaminophen Syrup
Cough and Cold Syrup
What is the salt form of benzoic acid?
sodium benzoate
Which functions better as a preservative – sodium benzoate or benzoic acid?
benzoic acid bc it can penetrate the lipid bilayer
What is the function of Disodium Calcium EDTA?
stability
What is the function of Saccharin Sodium
artificial sweetener
What are potentials functions of sodium chloride in solution?
electrolytes, taste control
the amount of preservative required to protect a syrup against microbial growth varies with what 3 things?
-the proportion of water available for growth (free water)
-the nature and inherent preservative activity of the materials present in the formula
-the capability of the preservative itself
what are the concentrations of the preservatives sodium benzoate and benzoic acid?
same: 0.1%-0.2%
preferably 0.1% bc preservative is not good for our body
Name 3 commonly used preservatives and their effective concentrations
benzoic acid (0.1%-0.2%)
sodium benzoate (0.1%-0.2%)
combination of methyl-, propyl-, and butyl- parabens (totaling ~0.1%)
if the alcohol concentration is ____%, no preservative is needed
18
“syrups”
is this referring to the dosage form or a product?
dosage form – NOT product
Name 4 methods for the preparation of syrups
- solution of the ingredients with the aid of heat
- Solution of the ingredients by AGITATION, WITHOUT the use of heat, or the simple “admixture” of liquid components
- The addition of sucrose to am already prepared medicated liquid or to a flavored liquid
- Percolation of either the source of the medicating substance or the sucrose
Briefly discuss this method of preparing syrups:
“Solution of the ingredients with the aid of heat”
This is a RAPID method that produces a syrup with a pale yellow color.
In the presence of heat, sucrose undergoes hydrolysis to glucose (dextrose) and fructose.
this reaction is called INVERSION.
glucose and fructose are monosaccharides and are more sweet than sucrose. this results in a dark brown liquid that is VERY sweet.
when the solution is GREATLY overheated, it becomes amber in color and carmelizes
the method of preparing syrups – “Solution with the aid of heat” cannot be used under what circumstances?
this method cannot be used to prepare a syrup containing a thermolabile (readily destroyed by heat) or a volatile ingredient (readily evaporates)
explain the process, advantages and disadvantages of this method of preparing syrups:
“Solution by agitation without the aid of heat”
advantage: avoids the heat-induced inversion of sucrose
disadvantage: slow process
this produces an ODORLESS, COLORLESS SYRUP
in “solution by agitation without the aid of heat” method of preparing syrups….
as the sugar dissolves and saturation is approached, the _______ and _______ decrease
the dissolution rate and the concentration gradient decrease
in the method of preparing solutions with the aid of heat, are you increasing the intrinsic solubility?
NO.
you’re increasing the dissolution rate
explain the process of the percolation method of preparing syrups
percolation is an EXTRACTION process. The desired constituents are dissolved from a granulated or powdered drug by the controlled descent of a suitable solvent through a column of the drug
the powdered/granulated drug is packed into the percolator. Layer of loosely packed cotton is over the lower outlet. Purified water or another suitable solvent is then added to extract the constituents from the powdered/granulated drug
percolation is a ___ process
extraction
explain what a percolator is
a cylinder or tapered vessel with a lower outlet from which we can control the flow
define elixirs
elixirs are CLEAR, SWEETENED, FLAVORED, HYDROALCOHOLIC solutions
which are more sweet – elixirs or syrups?
syrups are more sweet
elixirs are intended for which route of administration?
oral
what is the alcohol content range for elixirs?
5%-40%
elixirs contain ____ soluble and ___ soluble substances
water soluble AND alcohol soluble.
remember – elixir is hydroalcoholic
name some other solvents (besides alcohol and water) that are used in elixirs
glycerin and propylene glycol (PPG) are used as adjunct (co) solvents
what are some sweeteners used in elixirs?
sucrose (natural sweetener)
sorbitol (alcohol sweetener – NONSUGAR)
glycerin (NONSUGAR)
saccharin (artificial sweetener)
Do elixirs contain sugar?
yes
can elixir exist that contains no alcohol?
yes – usually for pediatrics
if PPG is in elixir, what is it being used for?
cosolvent
does phenobarbital need a cosolvent?
yes – it is not in its salt form
what is the function of orange oil in phenobarbital elixir?
flavoring agent
what is the function of Lemon Oil in Theophylline Elixir
flavoring agent
“Alcohol”
is this referring to a product or no?
YES
Alcohol, USP — 95% v/v of ethanol
“Syrup”
Is this referring to a product or no?
YES
Syrup, NF
85g sucrose in 100mL purified water
explain the process of preparing ELIXIRS
The alcohol-soluble substances are dissolved in alcohol
the water-soluble substances are dissolved in water
**The AQUEOUS SOLUTION is then added to the ALCOHOLIC solution and stirred
the excess oil that does not fully dissolve is filtered from the mixture by TALC to give a clear solution
WHY is it that the aqueous solution is added to the alcohol solution and not the other way around?
to maintain the highest possible alcoholic strength at all times so that minimal separation of the alcohol-soluble components occurs
why is talc used as a filtering agent?
it has a lot of surface area
what are the types of elixirs?
nonmedicated elixirs and medicated elixirs
name 2 ways in which nonmedicated elixirs may be useful to a pharmacist
-for the addition of a therapeutic agent to a pleasant tasting vehicle
-for the dilution of an existing medicated elixir
In selecting a liquid vehicle for a drug substance, what factors need to be considered?
the solubility and the stability of the drug substance in both WATER and ALCOHOL
(remember.. elixir is a hydroalcoholic mixture)
name 3 commonly used nonmedicated elixirs
-aromatic elixir
-compound benzaldehyde elixir
-Iso-Alcoholic elixir
explain what medicated elixirs contain that makes them different from a nonmedicated elixir
a therapeutic agent — could be a single agent, or 2 or more
name 4 examples of medicated elixirs
Antihistamine Elixirs
Barbituate sedative/hypnotic elixirs
Phenobarbital elixir
Digoxin elixir
explain what a tincture is
a tincture is an alcoholic or hydroalcoholic solution of chemicals or soluble constituents of crude drugs (vegetable/plant materials?)
how is a tincture prepared?
by an EXTRACTION process of maceration or percolation
rank the following according to alcohol content:
syrups
tinctures
elixirs
most alcohol: tincture
middle: elixir
least syrups
explain the storage conditions for tinctures
must be tightly stoppered and kept from excessive temps, due to their high alcohol content
also, must be stored in LIGHT RESISTANT CONTAINERS. bc many of the constituents found in tinctures undergo photochemical changes when exposed to light
besides tinctures, what else should avoid heat?
elixirs – alcohol content
