Exam 4 Spring 2017 Flashcards
How do you apply semi-solid preparations?
topically
What are examples of non-medicated semi-solid preparations?
- emollient (moisturizer)
- skin protectant
What are the classifications of bases for semi-solids?
- oleaginous
- absorption
- water removable
- greaseless
other names for oleaginous bases
- hydrocarbon bases
- hydrophobic bases
oleaginous base properties
- highest occlusion properties
- most oily
- difficult to wash off skin
- difficult to incorporate aqueous agents
- immiscible with water
- used to protect skin and emollient effects
examples of oleaginous bases
- regular and white petrolatum
- yellow and white ointment
absorption base properties
- able to absorb aqueous solutions to give w/o emulsion
- used for emollient effects
- difficult to wash off skin
examples of absorption bases
- hydrophilic petrolatum
- lanolin (wool fat)
water removable base properties
- also known as water washable
- external phase has to be water; o/w phase
example of water removable bases
hydrophilic ointment
greaseless base properties
- water soluble
- good for incorporating solid compounds
- soften with addition of water
example of greaseless bases
PEG ointment
What does PEG stand for and what are its other names?
- Polyethylene glycol
- PEO (polyethylene oxide)
- POE (polyoxy ethylene)
What are the ways in which you can prepare ointments?
- incorporation method
- fusion method (melt)
What materials can you use for the incorporation method?
- pill tile
- parchment paper
- unguator
- mortar and pestle
What is an unguator?
- electronic mortar and pestle
- equipment that goes inside the ointment jar an into the machine consists of a shaft and a blade
Define levigation
triturating a powder in an insoluble solvent
What are examples of levigating agents?
- mineral oil for oil phases
- glycerin for water phases
What are the steps to the incorporation method?
- incorporate drug into absorption base
- incorporate absorption base into oleaginous base
What is one thing to note when mixing ingredients in the fusion method?
mix the excipients with the highest melting point first
What are products that you HAVE to use fusion method for?
- beeswax
- paraffin
- stearyl alcohol
- PEG with high molecular weight
What are things to consider when selecting the appropriate bases?
- release rate of drug from semi-solid
- desirability of topical or percutaneous drug absorption
- desirability of occulsion of moisture from the skin
- stability of drug in base
- contact time to skin
- which part of the body it’s being applied to
What are dosage forms of semi-solids?
- ointments
- creams
- gels
- pastes
What does the # following PEG indicate?
the average molecular weight
PEG physical state with respect to molecular weight
- lower mw are liquid; higher mw are solids
- 200-600 transprent liquid
- 600-1000 semi-solid
- > 1000 solid
What materials can you use for the fusion method?
- small sacle: porcelain dish, glass beaker
- large sacle: large steam jacketed kettles
Common infections occur via which bacteria?
- Staphylococcus aureus
- Pseudomonas aeroginosa
The gram +/- terms were named after who?
Hans Christian Gram
Example of USP test for semi-solids
- minimum-fill
- microbial content
- packaging
- storage
- labeling
Properties of ophthalmic preparations
- diameter should be < 50microm
- sterile
Examples of preservatives
- paraben
- phenols
- benzoic acid
- sorbic acid
- quaternary ammonia compounds
- benzalkonium chloride
Properties of creams
- emulsions (usually o/w but can be w/o)
- can be easily washed off skin
- opaque
- once applied on skin, water evaporates and leaves behind a thin layer
Properties of gels
- aka jellies
- thixotropic
- must have gelling agent
Examples of gelling agents
- cabomer 940
- natural gums (tragacanth)
- cellulose derivatives ex:
- sodium carboxymethylcellulose
- HPMC
- carboxymethylcellulose
Properties of pastes
- must contain at least 20% of solid content
- able to absorb serous fluid
What are plasters used for?
to remove corn
What can glycerogelatin be used for?
varicose ulcer
TDD
- transdermal drug delivery
- aka percutaneous absorption
- absorb into system via skin
scopolamine
- approved by FDA 1979
- first TDDS approved
nitroglycerine
- aka trinitroglycerine
- used in angina pectoris and CHF
- releases NO (vasodilator)
clonidine
used for HTN
nicotine
used for smoking cessation
applications of creams
- topical skin products
- rectal and vaginal
properties of jars
- clear opaque glass
- plastic
properties of tubes
- aluminum
- plastic
aluminum tubes
coated with epoxy resin or vinyl to eliminate any interactions between tube and content
plastic tubes
made of high and/or low density polyethylene
What is a crimping clip?
a clip to seal off the end of a metal ointment tube
properties of skin
- in adult, covers 2m2
- weighs 11 lbs
- receives 1/3rd of blood circulation
- avoid first pass metabolism
anatomy of skin
- epidermis (outer layer)
- dermis (deeper layer)
properties of epidermis
- epithelial tissue
- semi-permeable membrane
- contain 90% keratinocytes and 8% melanocytes
properties of dermis
- strong connective tissue
- collagen and elastic fibers
How does drug molecule penetrate the skin?
via passive diffusion
layers of epidermis
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum germinativum / basale
Rotigotine
- used in parkinson
- brand name: Neupro
Rivastigmine
- anticholinesterase
- used for Alzhiemers
- brand name: Exelon
stratum corneum
rate limiting step for drug absorption
subq
- hypodermis; not part of the skin
What are the properties that influence transdermal absorption?
- physico-chemical properties
- drug concentration
- site of absorption
- hydration status
- time of contact
- race
- individual variation: disease state, genetic, age, etc.
What are the types of physico-chemical properties?
- molecular weight
- solubility; part. coeff. of 1 preferred
- dissociation constant
nature of carrier
What are the categories of enhancers for skin absorption?
- chemical
- iontophoresis
- electroporation
- sonophoresis
What are other names for chemical enhancers?
- absorption promoter / enhancer
- permeation promoter / enhance