Powders (Ansel's Pharmaceutical Dosage Forms 11th edition)

powder

a dosage form composed of a solid mixture of solids reduced to a finely divided state and intended for internal or external use

powder

provides a rapid onset of action because they are readily dispersed, have a large surface area, and usually require only dissolution, not disintegration, before absorption

very coarse (no.8)

all particles pass through a no.8 sieve, and not more than 20% pass through a no. 60 sieve

coarse (no.20)

all particles pass through a no. 20 sieve, and not more than 40% pass through a no. 60 sieve

moderately coarse (no. 40)

all particles pass through a no. 40 sieve, and not more than 40% pass through a no. 80 sieve

fine (no. 60)

all particles pass through a no. 60 sieve, and not more than 40% pass through a no. 100 sieve

very fine (no. 80)

all particles pass through a no. 80 sieve and there is no limit to greater fineness

sieving

particles are passed by mechanical shaking through a series of sieves

microscopy

sample particles are sized through the use of a calibrated grid background or other measuring device

sedimentation rate

particle size is determined by measuring the terminal settling velocity of particles through a liquid medium in a gravitational or centrifugal environment

light energy diffraction

particle size is determined by the reduction in light reaching the sensor as the particle passes through the sensing zone

laser holography

a pulse laser is fired through an aerosolized particle spray and it's photographed in three dimensions allowing the particles to be individually imaged and sized

cascade impaction

driven by the principle that a particle is driven by an air stream will hit a surface in its path

micromeritics

the science of small particles

comminution or trituration

the reduction of particle size of a solid substance to a finer state in a mortar

levigation

commonly used in small-scale preparation of ointments and preparation to reduce the particle size and grittiness of the added powders

spatulation

the blending of small amounts of powders by movement of a spatula through them on a sheet of paper or an ointment tile

mixing

a unit preparation involving the manipulation of a heterogeneous physical system with the goal of making it homogeneous

free-flowing mixtures

a type of mixture that suffers from a serious drawback of segregation of individual components during further processing in dosage form preparation

cohesive mixtures

a type of mixture that is not free flowing and where the individual agglomerates of particles must be repeatedly broken down and allowed to redistribute within the system to ensure a satisfactorily mixed product

ordered mixing

mixing of a fine, micronized form with larger carrier particles

geometric dilution

ensures uniform distribution of the potent drug

segregation

the undesirable separation of the different components of the blend

eutectic powders

a type of powder that may become sticky or pasty or may liquefy when mixed together

hygroscopic powders

a type of powder that will absorb moisture from the air

deliquescent powders

a type of powder that will absorb moisture from the air to the extent that they may partially or wholly liquefy

efflorescent powders

a type of crystalline powder that contains water of hydration or crystallization

topical powder

a type of powder that has a uniformed small-particle size that doesn't irritate the skin when applied

insufflated powders

a type of finely divided powders that are intended to be applied in the body cavity

aerosol powders, bulk powders, and divided powders

what are some examples of medicated powders?

powder papers

it may be of any size and used to hold the amount of powder required

simple bond paper

a type of paper not used for volatile components or substances affected by moisture

vegetable parchment

a type of paper that is semi-opaque and has limited moisture resistance

glassine

a transparent paper that limited moisture resistance and does not volatilize

waxed paper

a transparent and water-proof paper for volatile substances

glass mortar

a type of mortar that is used in preparing solutions and suspensions

wedgewood

a type of mortar suited for crystalline solids

porcelain

a type of mortar used for soft aggregates or crystals

aerosol powders

a medicated powder administered by inhalation with the aid of dry powder inhalers and delivers micronized particle of medication in metered quantities

bulk powders

a medicated powder prepared in bulk quantities that is limited to non-potent substances

divided powders

a medicated powder that is divided into individual dosing after it has been properly blended and is suitable for potent drugs