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55 Cards in this Set
- Front
- Back
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what are the most common degradative pathways
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oxidation and hydrolysis
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what is hydrolysis very common in
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esters (aspirin) and local anesthetics (benzocaine/procaine) and amides (procainamide)
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how do you prevent hydrolysis
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use less water
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what occurs in hydrolysis
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drug uptakes water and hydrolysises into two things
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what occurs in the hydrolysis of aspirin
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ASA + H2O > SA + HAc
SA = salicylic acid HAc = acetic acid TOO MUCH DECOMPOSITION OF SA CAN BE VERY BAD FOR YOUR STOMACH |
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why must aspirin be kept away from moisture
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to prevent it from hydrolysing
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what does light do to the decomposition rxn rate
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it decreases it because it puts extra energy into the system, but this can be prevented/reversed by using amber color vials
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what occurs in the hydrolysis of procainamide
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procainamide + H2O >p-aminobenzyl alcohol + Beta-diethyl aminoethanol
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what are the properties of local anesthetics
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local anesthetics (benzocaine and procaine) are susceptible to hydrolysis. they have a max stability in acid pH, but have a max effectiveness at neutral to slightly alkaline pH.
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how can you improve stability of benzocaine
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complex it with caffeine
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what are the properties of Auralgon otic solution
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it is susceptible to both oxidation and hydrolysis.
made using dehydrated glycerin. contains antipyrine (sensitive to oxidation) and benzocaine (sensitive to hydrolysis) |
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what is antipyrine sensitive to
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oxidation
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what happens everytime you open a bottle Auralgon otic solution
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you uptake moisture leading to the solution picking up 1% water which leads to oxidation and hydrolysis
if lose 1-2% antipyrine still effective but not pretty |
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what causes discoloration
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oxidation
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what is the Free SA % in powder
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.1%
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what is the free SA % in supp
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3%
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what is the free SA % in tabs
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.3% but (3% in buffered tablets)
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why can buffered tabs have a higher % of SA
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due to buffereing agent (aluminum hydroxide)
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how do you prevent oxidation
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use antioxidants
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what is considered oxidation
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removal of an electron
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what is oxidation common in
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very common in catecholamines (epinephrine/dobutamine), ascorbic acid, KI solution
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how can you prevent hydrolysis
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store in dry places
if sensitive to water use non aqueous solvents (glycerin propylene glycol) to replace some or all of the water |
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what are the properties of B6
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folic acid is very stable in solution but when mixed with B2 (riboflavin) it gets oxidized (gaining color) and riboflavin gets reduced (losing color)
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what happens to the color of the reducing agent
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it gains color
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what happens to the color of the oxidizing agent
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it loses color
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what happens when vit c undergoes oxidation
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ascorbic acid gets oxidized to dehyroascorbic acid then into oxalic acid (dangerous)
oxalic acid forms insoluble salt w/ calcium |
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what is auto-oxidation
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oxidation caused my molecular O2 due to presence of a free radical which is very reactive
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what is a free radical
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an unpaired electron
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how is the chain reaction caused by free radicals stopped
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use of antioxidants or when a free radical reacts with another free radical
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what are the properties of antioxidants
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lower oxidation potential than the drug they're trying to preserve
THIS MEANS ANTIOXIDANTS HAVE TO BE OXIDIZED 1ST |
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what is EDTA
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chelating agent (prevents the catalytic effects of traces of metal ions)
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how is EDTA used
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it is added with antioxidants to form a complex with traces of metal ions otherwise the traces of metal ions will increase the rate of oxidation
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what can citric acid be used for
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chelating agent
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what are examples of catecholamines
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epinephrine
isoetharine isoproterenol THESE ARE LIFE SAVING DRUGS |
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what happens to epinephrine when it undergoes oxidation
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it loses 2 OH and becomes a QUINOID
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what are examples of things sensitive to light
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riboflavin
nifedipine sodium nitroprusside prochloroperazine |
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how should nitroglycerine be stored
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in a plastic container
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what are examples of stuff sensitive to light due to their color
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phenothazine derivatives (prochlorperazine)
vit B2 (riboflavin) - orange yellow nifedipine - yellow |
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what are the properties of sodium nitroprusside
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very sensitive to light
must be wrapped in opaque cover 1hr of exposure leads to loss of 28% of drug |
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what nm of light is not found in sunlight
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light bellow 290 nm
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what nm of light is eliminated light by windows
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light bellow 320nm
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what happens to 1-epinephrine
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it can change to D form. 1 form is 15-20x more potent than D form.
racemization of 1-epinephrine occurs at pH below 1.5 |
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what are the properties of chloral hydrate
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can sublime
only soft gels available |
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amyl nitrate
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can evaporate out
use solid ABSORBENTS (calcium phosphate/starch) |
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nitroglycerine tabs
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use propylene glycol as ADSORBENT
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what are the properties of Propranolol/Verapamil
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side effects occur due to R isomer
S isomer is the active form |
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what are the official temp definitions
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cold = 8 or bellow
cool = 8 - 15 room temp = 15-30 warm = 30-40 excessive heat = above 40 freezer -25 to -10 |
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what are the properties of light resistance containers
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290 to 450 nm
amber colored bottle or opaque covering |
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what are the properties of a well closed container
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protects from EXTRANEOUS SOLIDS and loss of drug under ordinary or customary conditions of handling, shipping, storage, distribution
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what are the properties of tightly closed containers
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protect from contamination EXTRANEOUS SOLIDS, LIQUIDS, OR VAPOR, and loss of drug from efflorescence, deliquescence, or evaporation under ordinary conditions of H, S, S, D and it is capable of tight reclosure
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what is physical instability
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biotech powders (protein based) can undergo denaturation (unfolding), surface adsorption, aggregation, and precipitation
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what could cause physical instability of biotech products
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foaming due to shaking, pH or temp change, agitation
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what are the physical instability of tabs
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they can't lose potency, but they may become harder upon standing and may not dissolve in the stomach and won't be therapeutically active
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what is the physical instability of emulsions
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breaking
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what is chemical instability
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drug decomposing
loss of potency or active ingredient |
