PHC - CHAPTER 8 - TOPICAL EXAM QUESTIONS AND ANSWERS GRADED A+
what are different topical and transdermal formulations and their bioavailability and how is it
administered? (2+1) - Answers • Delivers drugs to the skin and through the skin
• 1‐3% bioavailable: Solutions, lotions, creams, ointments, gels
• 30‐70% bioavailable: Patches
what are the desirable quality of topical and transdermal preparations? (4) - Answers • Stable
• Compatible with excipients
• Can be released from dosage form
• Cosmetically acceptable i.e. good skin feel, texture and fragrance
what are the formulation principles of of topical formulation? (5) - Answers - choice of drug
- drug release
- drug saturation
- alcohol
- occlusion
what should the choice of drug be? (2) - Answers • Low molecular weight
• Lipophilic
what should the drug release be? (3) - Answers - Rapid for locally acting
• Or slow (7 days) for systemic acting
• Drug can partition well between solvent and lipophilic skin barrier
what should the drug saturation be? (2) - Answers • Drug to be saturated in medium
• Easier to be released to the lipophilic barrier of skin
what is the use of alcohol in topical formulations? - Answers - Can partition into the skin
• Transient reservoir for drug
• Volatile -> evaporates -> saturated aqueous drug solution -> improve delivery into tissue
what is occlusion? (3) - Answers • Impermeable barrier covering the skin
• Hydrates the skin
, • Improves transdermal and topical delivery of drugs
what are the different choice of vehicles? and their chracteristics (2+1+1) (3) - Answers 1. Liquid
• Rapid, short‐term input
• Permeant to skin
2. • Semi‐solid
• Increased residence on the skin
3. Patch
• Extended drug delivery
• Gels for normal to oily skin
• Lotions for normal to dry skin
• Creams for dry skin
what is the choice for hairy area and for areas where there is constant rubbing, for wet, vesicular or
weeping lesion and for dry, thickened, scaly lesion? - Answers • For hairy areas: Lotion, gels or sprays
• For areas where there is constant rubbing: Creams or lotions
• For wet, vesicular or weeping lesion: Aqueous base formulation: Cream, lotion, gel
• For dry, thickened, scaly lesion: Fatty formulation: Ointments, paste
what are the different formulation types? (7) - Answers • Liquid formulations
• Semi‐solid formulations
• Ointments
• Gels
• Creams
• Multi‐phase semi‐solid formulations
• Solid formulations
what are different topical and transdermal formulations and their bioavailability and how is it
administered? (2+1) - Answers • Delivers drugs to the skin and through the skin
• 1‐3% bioavailable: Solutions, lotions, creams, ointments, gels
• 30‐70% bioavailable: Patches
what are the desirable quality of topical and transdermal preparations? (4) - Answers • Stable
• Compatible with excipients
• Can be released from dosage form
• Cosmetically acceptable i.e. good skin feel, texture and fragrance
what are the formulation principles of of topical formulation? (5) - Answers - choice of drug
- drug release
- drug saturation
- alcohol
- occlusion
what should the choice of drug be? (2) - Answers • Low molecular weight
• Lipophilic
what should the drug release be? (3) - Answers - Rapid for locally acting
• Or slow (7 days) for systemic acting
• Drug can partition well between solvent and lipophilic skin barrier
what should the drug saturation be? (2) - Answers • Drug to be saturated in medium
• Easier to be released to the lipophilic barrier of skin
what is the use of alcohol in topical formulations? - Answers - Can partition into the skin
• Transient reservoir for drug
• Volatile -> evaporates -> saturated aqueous drug solution -> improve delivery into tissue
what is occlusion? (3) - Answers • Impermeable barrier covering the skin
• Hydrates the skin
, • Improves transdermal and topical delivery of drugs
what are the different choice of vehicles? and their chracteristics (2+1+1) (3) - Answers 1. Liquid
• Rapid, short‐term input
• Permeant to skin
2. • Semi‐solid
• Increased residence on the skin
3. Patch
• Extended drug delivery
• Gels for normal to oily skin
• Lotions for normal to dry skin
• Creams for dry skin
what is the choice for hairy area and for areas where there is constant rubbing, for wet, vesicular or
weeping lesion and for dry, thickened, scaly lesion? - Answers • For hairy areas: Lotion, gels or sprays
• For areas where there is constant rubbing: Creams or lotions
• For wet, vesicular or weeping lesion: Aqueous base formulation: Cream, lotion, gel
• For dry, thickened, scaly lesion: Fatty formulation: Ointments, paste
what are the different formulation types? (7) - Answers • Liquid formulations
• Semi‐solid formulations
• Ointments
• Gels
• Creams
• Multi‐phase semi‐solid formulations
• Solid formulations
