ceutics creams/ointments/gels

____________ are semisolid preparations intended for external application to the skin or mucous membranes

ointments

_____________ is a semisolid dosage form containing 1 or more drug substances dissolved/dispersed in suitable base (w/o, o/w, wwb)

creams

_____________ are semisolid systems consisting of either suspensions made up of small inorganic particles or large organic molecules interpenetrated by a liquid

gels

which dosage form is a suspension rather than an emulsion

a. ointment

b. cream

c. gel

c. gel

t/f: ointments are used only for local effects

false. for both local and systemic effects

t/f: ointments with systemic effects should be considered if the patient is pregnant or nursing since drugs can enter fetal circulation

true

topical vs transdermal derm products

topical= skin is target organ

transdermal= systemic effects

types of non-medicated ointments

1. emollients (softening)

2. protective barriers (anti-dehydrants)

3. base or vehicle (ex: bulk materials)

4 types of semisolid ointment bases

1. oleaginous (hydrocarbon)- hydrophobic

ex: vaseline

2. absorption (largely hydrophobic, some water capacity)

3. water-removable (completely removed by water)

4. water-soluble (completely dissolves in water)

which semisolid ointment base has the largest emollient effect? why?

oleaginous base

decreases the escape of moisture bc remains on skin for long time without drying since water immiscible

oleaginous bases examples

petrolatum, white ointment, mineral oil

what type of semisolid base is vaseline? what is it also known as?

-oleaginous base

-yellow petrolatum, petroleum jelly

which semisolid base is made up of hydrocarbons?

oleaginous base ("oily")

what levigating agent is used when powdered substances need to be incorporated into hydrocarbon bases

mineral oil (liquid petrolatum)

can absorption bases be removed with water?

no, not easily removed from the skin with water washing, because the external phase of emulsion is oleaginous

which semisolid base is used for w/o emulsification

absorption bases

2 types of absorption bases

1. emulsifiable base (HC): do not contain water but are designed to incorporate water to form an emulsion.

2. emulsified bases: already contain water as part of a W/O emulsion

emulsifiable base vs emulsified base examples

emulsifiable= hydrophilic petrolatum

emulsified= lanolin

lanolin

oil from sheep wool (<0.25% water) (ex of emulsified base- absorption)

t/f: absorption bases form o/w emulsions

false. form w/o. oil is external phase= thats why theyre not easily washed from the skin

water removable bases

o/w emulsions resembling creams

- easily washed from skin since external phase is aqueous

t/f: water removable bases can be diluted with water or aqueous solutions

true. the external phase is aqueous

t/f: absorption bases can be diluted with water or aqueous solutions

false. they are w/o emulsions so external phase is oil

which semisolid base is used to absorb serious discharges

water-removable bases (o/w emulsions), pastes

water-soluble bases

- NO oleaginous components, "greaseless"

- completely water washable

which semisolid base is used for the incorporation of solids

water-soluble bases

t/f: water soluble bases are completely water washable since only 10% of their composition is oil

false. they are completely water washable because they are completely hydrophilic. they do not have any oils

If 6 to 25% of an aqueous solution is to be incorporated into PEG ointment, replace 50g of PEG with ____________________

stearyl alcohol

which bases act as occlusive emollients?

oleaginous, absorption

which bases are greasy?

oleaginous, absorption

which base is anhydrous and can absorb some water

absorption

which bases are water washable

water-removable, water-soluble

which bases are nongreasy

water-removable, water-soluble

which base can be diluted with water

water-removable

which bases are non-occlusive (do not create barrier)

water-removable, water-soluble

which 4 factors contribute to the proper choice in base

1. action desired (release rate, topical? percutaneous?)

2. physical and chemical drug properties

3. bioavailability and stability

4. characteristic of surface its applied to

depending on the surface its applied to, when should you use

ointment:

cream:

lotion:

ointment: dry scaly skin

cream: weeping or oozing surfaces

lotion: intertriginous (skin rubs together)/ areas of friction

what would you apply on areas that rub together

lotion

what would you apply on an oozing surface

cream

what would you apply on dry scaly skin

ointment

2 ways to prepare ointments

1. incorporation/ levigation: dry powder + liquid physically mixed

2. fusion: melted together and cooled while mixing

requirements for ointments

1. microbial content

2. minimum fill

3. packaging, storage, labeling

also: sterility, metal particles content

3 types of cream bases

1. w/o

2. o/w

3. wwb (water washable base)

which cream bases can be removed with water

o/w and wwb

uses of creams based on area

-topical skin products

- rectal and vaginal (ease in spread and removal)

which dosage form is used for rectal and vaginal application? why?

creams-> preferred due to their ease in spread and removal

what is vanishing cream

o/w emulsion with HIGH water content

- humectant (preserves moisture)

- forms thin layer after water evaporates

2 classifications of gels

1. single phase system

- has uniformly dispersed macromolecules in liquid (fused)

2. two phase system

- small floccules uniformly dispersed in gel matrix (suspension)

- magma

what is milk of magnesia magma an example of

gel 2 phase system

= gelatinous precipitate of Mg(OH)2

gels may thicken on standing, forming a _____________, and must be shaken before use

thixotrope

what is added to gels, creams, and ointments to deliver drugs transdermally

penetration enhancer

-DMSO, EtOH, PG, glycerin, urea, etc

DMSO, EtOH, PG, glycerin, and urea are all examples of

penetration enhancers

- used to give drugs transdermally

what are pastes

-semisolid dosage forms that contain 1+ drugs for topical application

- stiff; remain in place after application

- used to absorb serious secretions

which dosage form is used to absorb serious secretions bc of its stiffness, but is not compatible with hairy body parts

pastes

________________ are solid or semisolid adhesive masses spread on a backing of paper, fabric, moleskin, or plastic

plasters

why are plasters sometimes used over traditional dosage forms like gels or creams

adhesive masses provide prolonged contact at the site

describe the makeup of the skin surface

- film of emulsifies sebum, sweat, epidermal cells

- varies bc of sebum amount, washings, sweat evaporation

t/f: hair follicles and gland ducts can provide entry ways for drugs

true

how do drugs pass through the stratum corneum

diffusion

what does the rate of drug absorption through the stratum corneum depend on

drug Concentration

Aqueous solubility

o/w Partition coefficient

CAP

t/f: only drugs with aqueous solubility are good for stratum corneum penetration

false. substances with both aqueous and lipid solubility

t/f: the therapeutic effective drug concentration in the skin can be calculated based on pt

false. it is not known. treatment is based on qualitative measures which is why clinical efficacy varies

how would you counsel a pt on cream/gel/lotion use

1. clean affected area with soap and water-> dry

2. apply thin layer of medication with gentle pressure

3. unless specified, do not cover with bandage

4. if symptoms persist or irritation occurs, stop and talk to doc

t/f: in gels/ creams/ ointments use, allergic responses are fairly uncommon

false. they are common

non-derm topical applications of creams/gels/ointments

eyes, ears, nose, vagina

which dosage forms are used opthamically

sterile ointments and gels

for the eye, how do most drugs enter

simple diffusion through cornea conjunctiva and sclera

in addition to the regular ointment quality standards, what standards do ophthalmic have?

1. sterility

2. metal particle tests

t/f oleaginous bases increase the escape of moisture from the skin

false

absorption bases form ________ emulsions

w/o

water removable bases (select all that apply)

a. form o/w emulsions

b. resemble creams

c. form w/o emulsions

a,b

ointments used for transdermal application can be used to (select all)

a. achieve topical effect

b. deliver drug to circulation

c. deliver drug into skin

d. achieve systemic delivery

a,b,c,d (all)