definition of ointments
USP: semisolid preparations intended for external application to the skin or mucous membranes
–loosely to include: pastes, creams, gels, plasters, poultices (all semisold topicals)
UNG (latin): fatty substance
Specific definition of ointments
Levigation - when is it used?
what is incorporation?
-the processes of combining semi-solid masses
when do you use geometric?
-used with “geometric incorporation”
What are levigating agents?
When are levigating agents used?
what are solubilization agents?
Scenario: a solid, oil-soluble drug to be incorporated with petrolatum
1) dissolve the drug in a minimal amount of mineral oil (on the ointment slab)
2) incorporate (geometrically if needed) oil solution with the petrolatum
Scenario: a solid, water-soluble drug is to be incorporated with petrolatum
1) dissolve the drug in a minimal amount of distilled H2O (usually on the ointment slab)
2) incorporate the solution in a minimal amount of an appropriate absorption base
3) incorporate the above with the petrolatum
Scenario: a solid, powder substance is to be incorporated in an ointment base in which it it NOT soluble
1) levigate the powder in a minimal amount of the base (or levigating agent)
2) incorporate the remaining ointment base with the product
Definition of creams
Definition of gels
USP: gels are semisolid systems consisting of either suspensions made up of small inorganic particles or large organic molecules interpenetrated by a liquid
–> a specific type of ointment
Definition of pastes
USP: pastes are semisolid dosage forms that contain one or more drug substances intended for topical application
-generally high viscosity: stiff, protective property, generally an ointment with >20% w/w powder = paste
How are ointments generally used?
- external use only –> exceptions = gels! (mylanta gelcaps, metrogel)
Topical ointments
Transdermal ointments
-site of application may be the same but the intent is for the active ingredient to become systemically distributed through absorption into the blood
Ointment uses: emollient*
is an ointment protective?*
yes! depending on the viscosity & stiffness of the individual base, one may be more protective than the other
Is an ointment a medication vehicle?*
usually yes, but maybe not –> can have active ingredient or are sometimes just used for their protective or emollient properties alone
Use of ointment as a term *(both general & specific)
* specific: ointment = oleaginous/hydrocarbon base class
what is the ideal ointment?
what stability characteristics do we wants in an ointment?
physical, chemical, microbiologic
What are some ointment bases? (5)
1) hydrocarbon/oleaginous
2) anhydrous absorption
3) water in oil emulsion (topical)
4) oil in water emulsion (oral)
5) water soluble