Lecture 9 Flashcards
What are the main functions of human skin?
It serves as a barrier against external factors (e.g., pathogens, pollution, temperature changes, humidity, and sun radiation), regulates internal conditions (e.g., blood pressure and temperature), and mediates sensations.
What are the three main layers of the skin?
Epidermis, dermis, and subcutaneous fat.
What is the primary role of the epidermis?
It controls drug absorption and protects the skin through its outermost layer of corneocytes (dead keratinocytes).
What is the significance of the dermis in drug absorption?
Its rich blood supply promotes the absorption of topical drugs
What does the subcutaneous tissue do?
It provides mechanical cushioning, thermal insulation.
What are the five main target regions for drug delivery through the skin?
Surface treatment, viable epidermis, dermis, skin glands, and systemic circulation.
Topical dosage forms
powders, semi-solids and liquids
What are powders used for in topical applications?
As dusting powders, they dry, protect, and lubricate the skin
Describe gels in topical formulations.
Gels are semi-solid systems with a hydrophilic and hydrophobic component.
What is the role of ointments in topical drug delivery?
Ointments are oil-based, semi-solid preparations used for their emollient and occlusive properties.
2 groups of creams
oil in water (O/W) and water in oil (W/O).
Oil in water composition
Small droplets of oil in continuous aqueous phase.
Water in oil composition
Small droplets of water dispersed in a continuous oily phase.
Wound
A defect or break in the skin.
How are wounds classified?
Classified based on the number of skin layers affected.
