liquid dosage forms Flashcards
(28 cards)
what is liquid dosage form?
is a pourable pharmaceutical preparation containing an active drug and exepients dissolved or suspended in a suitable solvent
classify liquid dosage forms
monophasic
biphasic
advantages of liquid dosage forms ;6 POINTS
suitable for patients with difficulties in swallowing
more readily absorbed than solid
distribution of dosage is better than solids
more economical to produce
can be designed for any route of admin
dosage can easily be adjusted accordin to patients needs
disadvantages of liquid dosage forms ;5 points
+drugs are less stable in solid as are in liquids
+they are more succeptible to microbial contamination
+administration is less precise as it is based on patient measurements
+are more bulky to carry than solid forms
+easily affected by temperature,light and microorganism
+loss may occur if the container breaks
excipients used in liquid dosage forms(4poits)
vehicles(water,glycerine,alcohol)
stabilizers;increase stability by preventig degradation
preservatives;prevent microbial activities
suspending agents;suspend APIs prevent decantation
emulsifying agents(talc)absorb water-oil droplets
define sulibilization(sulubility enhancement)
is a technique of improving solubility of poorly soluble drugs by the use of surfactants
what are the techniques of solubility enhancement (6 points)
particle size reduction nanonization cosolvency hydrotopy pH adjustment complexation
define monophasic liquid dosage forms
means two or more liquid preparations existing in one phase
classify liquid dosage forms (2 with examples)
1.internal administration(syrups,elixirs,linctuse)
2.external administration(gargles,mouthwash,paints,douches,eardrops,
nasaldrops,eyedrops)
define syrups
are sweet viscous concentrated solutions of sucrose in purified water and other API(acqueous liquid)
what are the two methods of syrup preparation
agitation method
percolation method
what are the two types of syrups
nonmedicated syrups(only sucrose and water, medicated syrup(atleast one water soluble API)
define elixirs
are clear aromatic sweetened hydro-alcoholic preparation intended for oral use
define linctuses
is a viscous liquid which is taken orally prepared for cough relief
what are gargles
is an acqueous solution containing antiseptics or antibiotics used to treat throat infections eg povidone iodine
define mouth wash
is an aqueous solution with pleasant taste used to clean and deodorize the buccal cavity
define throat paints
are viscous preparations used for mouth and throat infections and is usualy applied by a soft brush or cotton swab
mention two forms of biphasic liquids
emulsion
suspension
define an emulsion
is a biphasic system consisting of two imiscible liquids in which one is finely subdivided and uniformly dispersed throughout the other
mention the four types of emulsion
oil in water
water in oil
multiple emulsion
microemulsion
what are the pharmaceutical applications of emulsions (advantages)
- helps to make some drugs more palatable by masking the odor and bad taste eg codliver oil emulsion
- can prolong the release of drug-sustained action
- protects drugs from oxidation or hydrolysis by making them stable
- are used to prepare pharmaceutical preparation for external use eg lotions,creams
what are disadvantages of emulsions
- they are highly unstable
- succeptible to temperature and pH changes
- size of globules makes it less favourable for parenteral administration
what is the purpose of identification tests
to tell apart between o/w and w/o emulsions
mention the 4 identification tests for emulsions
-dilution test
-conductivity test
-dye solubility test
cobalt chloride test