Intro to Solid Dosage Forms Flashcards
Why do we need dosage forms?
convenient and safe delivery of accurate dosage
avoid drug degradation
to improve palatability
to provide in a form that can be administered
to control drug release rate
What dosage forms are out there?
Tablets
capsules
solutions
suspensions
emulsions
powders
ointments
creams
Steps in formulation development
pre-formulation studies
formulation
testing in a biological system
Advantages of Solid Dosage Forms
unit dose
cost of shipping
no breakage or leakage
masking taste less difficult
more portable
require less space per dose
good physical and chemical stability
elegant distinctive appearance which has a high patient acceptability
Disadvantages of Solid Dosage Forms
potential bioavailability problems
potential irritant effect on GI mucosa
occasional difficulty in formulation
manufacturing can be more technical or specialized
Physical Properties of solid dosage forms
flow properties when mixing powders
stability in the solid state
solubility and dissolution rate
biological activity
types of compounded powders
bulk powders for internal use
other bulk powders
Dissolution rate
the rate at which the particle dissolves.
By increasing the surface area, one may increase the bioavailability for some poorly soluble drugs, because there is often a direct relationship between dissolution rate and bioavailability and drug absorption.
Suspendability
the ability of particle to remain undissolved but uniformly dispersed in a liquid vehicle
Accuracy of Dosage Form
there must be uniform distribution of drug substance in a powder mixture or dosage form and to ensure batch to batch uniformity
Penetrability
the ability of particle to reach their intended location
non grittiness
do not want solid particle in dermal products to feel “gritty”. Finer particles allow for a smoother texture and better appearance and flow. This is also important for oral products such as chewable tablets.
chemical stability
refers to degradation reaction
smaller particles have an increased surface area, leaving them more exposed and vulnerable to reaction with oxygen, water and light
Flowability
effect on flow properties of powders and mixing of powders and granules
this is important in the manufacturing of tablets and capsules
Compressibility
effect on adhesion and sticking together when compressing granules into tablets
this is important in the manufacturing of tablets and capsules
Sieving
size is expressed in terms of mesh, where mesh is the number of openings per linear inch of a screen
therefore, the larger the mesh, the smaller the particles
Advantages of the Sieving method
inexpensive, simple and fast
disadvantages of the sieving method
does not provide as much information as microscopy
Define monodisperse powders
powders containing particles of uniform size (RARE)
define polydisperse powders
particle size varies a great deal
Define comminution
the mechanical process of reducing particle size of a solid substance to a finer state of subdivision
where the three manually operated procedures in a small scale comminution
trituration
levigation
pulverization by intervention
define trituration
the process of grinding a drug in a mortar to reduce its particle size
define levigation
the process of mixing a powder with a liquid or semi solid vehicle in which the powder is insoluble to form a smooth paste
define pulverization by intervention
particle size reduction with the aid of an additional material which can be later removed
what is small scale comminution
most commonly involves the use of a mortar and pestle
Industrial Comminution
milling is industrial scale or mechanical process of reducing particle size
List examples of milling equipment
coarse crushers
intermediate grinders
fine grinding mills
Define trituration
using a mortar and pestle and mixing in a single operation
define spatulation
blending powders with a spatula on a tile or paper
Define Sieving
used to help reduce loosely held agglomerates or to increase overall effectiveness of a blending process
Ideal large scale industrial mixer should
produce a complete blend rapidly with as gentle as possible a mixing action to avoid product damage
be easily cleaned and discharged
be dust-tight
require low maintenance and low power consumption
Define oral powder
usually used after mixing in water
this dosage form is preferred by pt unable to swallow other solid dosage forms
define topical powders
external application to the skin
most powders are used this way
Definition of powder
a mixture of dry, finely divided drugs and/chemicals that may be intended for internal or external use
Advantages of powders
flexibility in compounding
suitable for infants and young children who cannot swallow tablets or capsules
rapid onset of drug action because disintegration is not required
can be applied to many body cavities such as ears, nose, tooth sockets and throat
relatively good chemical stability
Disadvantages of powders
potential for misunderstanding of the correct method of use that can lead to inaccurate dosing
undesirable for bitter or unpleasant tasting drugs
difficult to protect hygroscopic
time consuming to prepare uniform wrapped doses
Advances of Powder formulations
particle size
taste masking
route of delivery
delivery device
List other bulk powders
dusting powders
dentifrices
douche powders
others
Explain what a dusting powders
medicated or non-medicated powders for topical application
Explain what dentifrices are used for
dental cleaning powders
denture powders
Explain what douche powders are
completely soluble powders
intended to be dissolved in water prior to use as antiseptics or cleansing agents for a body cavity
Explain the need for bulk powders for oral use
a convenient method of dispensing nonpotent, powdered drugs, which hace doses that require large volumes of powder
General Comments about bulk powders for oral use
usually dispensed in wide mouth containers
dose is measured volumetrically by the pt
often administered using a household measuring device
