D Flashcards
(30 cards)
What are the four main types of ointment bases?
Hydrocarbon, Absorption, Water-removable, and Water-soluble bases.
What is a hydrocarbon base?
An occlusive, water-free base like petrolatum that retains moisture and stays on skin.
What are absorption bases?
w/o emulsions that can absorb small amounts of aqueous solutions, e.g. lanolin.
What are water-removable bases?
o/w emulsions that can be easily washed off skin.
What are water-soluble bases?
PEG-based bases that are greaseless and washable.
What is the difference between ointments, creams, and pastes?
Ointments are greasy; creams are emulsions; pastes are thick with >50% insoluble solids.
What are the primary uses of semisolid dosage forms?
Topical delivery for local effects such as protection, lubrication, or medication.
What is geometric dilution?
A mixing method used to evenly distribute a small amount of drug into a larger base.
Name the three emulsifier types used in creams.
Anionic (e.g. SLS), Cationic (e.g. QACs), Nonionic (e.g. cetomacrogol).
Which emulsifiers are least irritating?
Nonionic emulsifiers.
What HLB value range favors o/w emulsions?
8–18 (hydrophilic).
What are pastes?
Ointments with a high proportion of insoluble solids like zinc oxide.
Why are pastes used as protectants?
They form barriers and absorb irritants or exudates.
What are ophthalmic ointments?
Sterile ointments for eye use with softening points near body temperature.
What are two key sterilization requirements for ophthalmic ointments?
All components must be sterilized separately and combined aseptically.
What are the three main ointment preparation methods?
Incorporation, fusion, and emulsification.
What is the incorporation method?
Mixing ingredients into the base using a slab and spatula or Unguator.
What is the fusion method?
Melting ingredients, combining, then cooling with stirring to form a semisolid.
When is emulsification used?
To make creams using a two-phase heating method (oil and water phases).
What equipment is used for manufacturing large batches of ointments?
Stainless steel planetary mixers and ointment mills.
What is levigation?
Reducing particle size of a powder by mixing with a small amount of base or levigating agent.
Give an example of a levigating agent for oleaginous bases.
Liquid paraffin.
What is the Unguator used for?
An electronic mortar and pestle system to mix ingredients directly in the dispensing jar.
What are five product-plastic interaction categories?
Permeation, leaching, sorption, chemical reaction, and physical alteration.
