Ointments

Question 1

What is an ointment?

Answer 1

A semi-solid dosage form, usually anhydrous with a hydrophobic oily base, intended for external application to the skin or mucous membrane.

Question 2

Ointments are Occlusive

Answer 2

Increases skin hydration by minimising transepidermal water loss. Also enhances dermal drug penetration.

Question 3

Ointment are Emollient

Answer 3

Suitable for dry skin

Question 4

3 types of ointment

Answer 4

– Hydrophobic (oleaginous) ointment

– Water emulsifying ointment

– Hydrophilic (greaseless) ointment

Question 5

Hydrocarbon bases for hydrophobic ointment characteristics (3)

Answer 5

– Occlusive—emollient effect

– Not water-washable

– Greasy

Question 6

Hydrocarbon bases for hydrophobic ointment example

Answer 6

Petrolatum (paraffin)

Question 7

Absorption bases for water emulsifying (W/O) ointment characteristics (4)

Answer 7

– Form w/o emulsions with skin secretions.

– W/O emulsifier

– Emollient effect

Question 8

Absorption bases for water emulsifying (W/O) ointment example

Answer 8

Lanolin and derivatives

Question 9

Water-removable bases for water emulsifying (O/W) ointment characteristics (3)

Answer 9

– Form O/W emulsions with skin secretions.

– O/W emulsifier

– Water-washable

Question 10

Water-removable bases for water emulsifying (O/W) ointment example

Answer 10

Cetostearyl alcohol, cetomacrogol.

Question 11

Water-soluble bases for hydrophilic ointment characteristics (2)

Answer 11

– Water-washable

– Non-greasy

Question 12

Water-soluble bases for hydrophilic ointment example

Answer 12

Macrogols (polyethylene glycols = PEG)

Question 13

2 basic comportments of an ointment

Answer 13

Drug

Ointment base

Question 14

Ointments may also contain (3)

Answer 14

Solvent

Antioxidant

Emulsifying agent

Question 15

Solvent purpose in ointment

Answer 15

to dissolve components, miscible with ointment base.

Question 16

Antioxidant purpose in ointment

Answer 16

to prevent oxidative degradation. (reacidification)

Question 17

Emulsifying agent purpose in ointment

Answer 17

for water emulsifying ointments.

Question 18

Why are preservatives not generally required in ointments

Answer 18

As no water content.

Question 19

Betnovate ointment

Answer 19

For relief of inflammatory and pruritic manifestations of steroid-responsive dermatoses.

Question 20

White soft paraffin purpose in Betnovate

Answer 20

Ointment base

Question 21

Liquid paraffin purpose in Betnovate

Answer 21

Ointment base

Question 22

White soft paraffin purpose in Fucidin Ointment

Answer 22

Ointment base

Question 23

Liquid paraffin purpose in Fucidin Ointment

Answer 23

Ointment base

Question 24

All-rac-alpha-tocopherol ​purpose in Fucidin Ointment

Answer 24

Vitamin E antioxidant ​

Question 25

Butylhydroxytoluene purpose in Fucidin Ointment

Answer 25

Antioxidant ​

Question 26

Cetyl alcohol purpose in Fucidin Ointment

Answer 26

Emulsifier ​

Question 27

Lanolin (wool fat) purpose in Fucidin Ointment

Answer 27

Ointment base

Question 28

Rancidification

Answer 28

Oxidative chain reaction mediated by free radicals, changing organoleptic properties due to chemical decomposition.

Question 29

What does rancidification happen to?

Answer 29

Particularly to oxygen-containing fats and oils derived from animals or plants.

Question 30

How do antioxidants work?

Answer 30

Deplete free radicals, thus terminating oxidative chain reactions. Needs to be soluble in ointment base.

Question 31

Example of water emulsifying ointment

Answer 31

Fucidin Ointment

Question 32

Fucidin Ointment

Answer 32

Treatment of skin infections caused by sensitive strains of S. aureus, streptococcus spp and Corynebacterium minutissimum.

Question 33

How to incorporate a drug into an ointment (3)

Answer 33

- Dissolve directly in ointment base. - Dissolve drug in a suitable solvent, then incorporate solution into ointment base. - Levigate solid drug into ointment base to disperse evenly, with geometric dilution.

Question 34

What is levigation?

Answer 34

Crushing particles in presence of a fluid (levigation fluid) to reduce particle size as it being incorporated into ointment.

Question 35

Two types of penetration enhancers

Answer 35

Physical and chemical

Question 36

Chemical penetration enhancer (CPE) auxiliary equipment?

Answer 36

- Included as an excipient in formulation. | - No requirement for auxiliary equipment.

Question 37

Physical enhancement auxiliary equipment?

Answer 37

Usually requires auxiliary equipment.

Question 38

Physical enhancement examples

Answer 38

Microneedles, iontophoresis, electroporation, sonophoresis, laser ablation, thermal ablation.

Question 39

Chemical penetration enhancer (CPE) increase permeability by…

Answer 39

Drug partitioning

Question 40

What does the Lipid-protein-partitioning theory propose

Answer 40

Proposes that the skin has lipophilic and hydrophilic domains.

Question 41

Lipid-protein-partitioning theory: lipid

Answer 41

Disrupting stratum corneum lipids (lipophilic domain), increasing diffusivity (D) for lipophilic drugs.

Question 42

Lipid-protein-partitioning theory: Protein

Answer 42

Altering stratum corneum proteins (hydrophilic domain), increasing diffusivity (D) for hydrophilic drugs.

Question 43

Lipid-protein-partitioning theory: Partitioning

Answer 43

Enhancing drug partitioning from formulation into skin, increasing partitioning (K).

Question 44

Ideal properties of penetration enhancers (2)

Answer 44

– Chemically inert and non-toxic. – Transient, reversible and selective penetration enhancement effect.

Question 45

What type of molecules act as strong chemical penetration enhancers

Answer 45

Amphiphilic compounds that have a polar head group and long hydrocarbon tail.

Question 46

What do Amphiphilic compounds resemble in relation to the skin?

Answer 46

Stratum corneum (SC) lipids

Question 47

How do amphiphilic compounds work as chemicals penetration enhancers?

Answer 47

Insert into SC extracellular lipids to loosen packing.

Question 48

Examples of amphiphilic compounds as chemicals penetration enhancers

Answer 48

Surfactants, fatty alcohols, fatty acids, phospholipids.

Question 49

What type of amphiphilic compounds are most effective as chemicals penetration enhancers?

Answer 49

Unsaturated (double bond) and cis hydrocarbon tail more effective.

Question 50

Why are cis isomers more effective than unsaturated (trans)?

Answer 50

The cis has a kink which forces open a gap in the SC lipid structure which allows small molecules to pass through.

Question 51

Polar CPE are more effective on what type of drug?

Answer 51

Hydrophilic

Question 52

Non-polar CPE are more effective on what type of drug?

Answer 52

Lipophilic