Incompatibilities Flashcards
Types of Physical Incompatibility
Incomplete Solution
Precipitation
SEPARATION OF IMMISCIBLE LIQUIDS
LIQUEFACTION OF SOLID INGREDIENTS (EUTEXIA)
INCORRECT FORM PRESCRIBED
GELATINIZATION
Mucilaginous, albuminous substances and some metallic salts are precipitated from aqueous solution by the addition of __________
alcohol
Camphor in camphor water and volatile oils are precipitated from aromatic waters when ____________are dissolved in the liquid
metallic salts
Boric acid is precipitated when ____________ is added in a saturated solution
tragacanth
Colloidal solutions show precipitation on addition of _____________
electrolytes
Precipitation Examples:
Mucilaginous, albuminous substances and some metallic salts + Alcohol
Camphor and volatile oils + metallic salts
Boric Acid + Tragacanth
Colloidal soln + electrolytes
Oils dissolved in alcohol separate with the addition of water
SEPARATION OF IMMISCIBLE LIQUIDS
Spirit of ethyl nitrate + potassium citrate =
SEPARATION OF IMMISCIBLE LIQUIDS (separation and layering)
lowering of the melting point when two ingredients are mixed and tend to liquefy
Eutexia
Example of intentional eutexia
Camphor + menthol
Example: Alkaloid salt to be dissolved in liquid petrolatum
INCORRECT FORM PRESCRIBED
Solution of acacia is gelatinized by the addition of ________
ferric salts
Collodion is gelatinized by _______
phenol
Ability to exist in several or different crystalline form
Polymorphism
Waterloss
Ointment -> Crumbling
Emulsions -> Crackling
Gels -> Syneresis
Compounds considered SOLUBLE
Acetates
Nitrates
Sodium Salts
Sulfates (except Ba, Sr, Pb, Ag)
K salts (except barbiturates)
Chlorides (except silver, mercurous)
Compounds considered INSOLUBLE
Carbonates and Phosphates (except alkalis)
Occurs instantaneously upon compounding
IMMEDIATE INCOMPATIBILITIES
IMMEDIATE INCOMPATIBILITIES examples
o Effervescence (bubbling) o Precipitation
o Color changes
o Explosion
DELAYED INCOMPATIBILITIES
Occur without appreciable visible change/immediate
physical evidence of change
Rx is dispensed if used up before about _______ of the
therapeutic activity is lost
10%
epinephrine turns to pink to brown ppt
oxidation
Silver, mercury, and gold salts may be _________ by
light to the metallic form.
reduced
Conversion of an optically active form to an optically inactive form without changing chemical constitution
Racemization
Thalidomide: R or S
Racemization
Tretinoin: iso or trans
Geometric isomerism
Example of chemical precipitation
Tannates + iron
Opium + lead solution
Iron + salicylates
Alkaloids from KI or Mercuric Chloride (Mayer’s reagent)
Green crystals of isonitroso antipyrine
Effervescence
EVOLUTION OF GAS
Na2[Fe(CN)5NO]Na Nitroprusside (potent vasodilator),
Vitamin B2, Nifedipine
PHOTOCHEMICAL DEGRADATION
produces effervescence or explosion with tannins or with oil of turpentine
Strong nitric acid
____________ explode with organic matter or oxidizable inorganic matter like sulfur and carbon
oxidizing agents
______________ may explode heated above 100C or
when combined with nitrates, chromates, or permanganates
Hypophosphites
__________ may explode when treated with ammonia or with oil of turpentine.
Iodine
Acacia + Bi salts
Cementation
KI + Hg2Cl2 (calomel), in the presence of moisture
Hg+2
Toxic
morphine + atropine
Opium + calomel
intentional or beneficial incompatibilities example
Emetine + antimony
Epinephrine + cocaine
Castor oil or fixed oil + santonin or aspidium
oleoresin
increase toxicity
COMBINATIONS LIABLE TO PRODUCE THERAPEUTIC INCOMPATIBILITIES
Sedatives + stimulants
Demulcents + irritants
Laxative + astringents
Strychnine + barbital derivatives
Caffeine + chloral hydrate
(sedative; knockout drug)
Atropine + morphine
Tannin + aloin