JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B. Pharmacy III Year COSMETIC SCIENCE Previous Question Paper (August - 2022 - R17)

The skin is the largest organ of the body, functioning as a protective barrier, thermoregulator, and sensory organ. It consists of three primary layers: the epidermis, dermis, and hypodermis.

The epidermis is the outermost, non-vascular layer composed mainly of keratinocytes. It is divided into five strata: stratum basale (cell division), stratum spinosum, stratum granulosum, stratum lucidum (in thick skin), and stratum corneum (the barrier layer of dead, keratinized cells). It provides protection against pathogens and water loss.

The dermis lies beneath the epidermis and is composed of dense irregular connective tissue containing collagen and elastin fibers, which provide strength and elasticity. It houses blood vessels, lymphatics, nerve endings, hair follicles, and sweat (eccrine and apocrine) and sebaceous glands.

The hypodermis (subcutaneous layer) consists of adipose tissue and loose connective tissue. It serves as an energy reservoir, provides thermal insulation, and acts as a shock absorber for underlying structures.

Cosmetics are products intended to be applied to the human body for cleansing, beautifying, or altering appearance without affecting the body's structure or function, whereas cosmeceuticals are hybrid products that bridge the gap between cosmetics and pharmaceuticals, containing bioactive ingredients that exert a therapeutic or physiological effect on the skin.

Classification of Cosmetics:

• Skin Care: Creams, lotions, moisturizers, and face masks.
• Hair Care: Shampoos, conditioners, hair oils, and dyes.
• Color Cosmetics (Makeup): Lipsticks, foundations, eyeliners, and nail polishes.
• Oral Care: Toothpastes and mouthwashes.
• Fragrances: Perfumes, deodorants, and colognes.

Classification of Cosmeceuticals:

• Anti-aging agents: Retinoids (retinol), peptides, and antioxidants like Vitamin C.
• Skin lightening agents: Kojic acid, niacinamide, and hydroquinone.
• Sun care/Photoprotective agents: Chemical filters (avobenzone) and physical blockers (zinc oxide, titanium dioxide).
• Moisturizing/Barrier repair: Ceramides, hyaluronic acid, and alpha-hydroxy acids (AHAs).