Biological Systems for Formulations Flashcards
Biological interface
boundary or interaction point between two biological (or non) systems
Aspects of biological interface
interaction with bio tissues, biocompatibility and safety, targeted delivery, plant-based formulations
Biomimicry
materials created inspired by design in nature
Human GI tract
open ended epithelium-lined tube from mouth to anus
Main steps of digestion
ingestion, propulsion, mechanical breakdown, enzyme digestion, absorption, defecation
Layers of the GI tract
mucosa, submucosa, muscularis externa, serosa
Mucosa
inner most layer, directly contact with digestive system. 3 sub layers
3 sub layers of mucosa
epithelium, lamina propria, muscularis mucosae
Epithelium
innermost sublayer, responsible for absorbing nutrients and secreting mucus, enzymes and hormones
Lamina propria
blood vessels and connective tissue support the epithelium
Muscularis mucosae
thin layer of smooth muscle help to move and fold mucosa
Submucosa
Muscularis externa
Serosa
Digestive enzymes
proteins essential for breaking down macromolecules into smaller
Enzyme classes
carbohydrases, protease, lipase
Bollus
food when leaving esophagus
Chyme
food when leaving the stomach
Small intestine
villi and microvilli absorb nutrients into bloodstream and lymphatic system
Stomach
mechanical and chemical digestion
sublingual delivery
under the tongue
Buccal delivery
through the lining of the cheek
Factors to consider with sublingual/buccal delivery
both avoid first pass metabolism. consider permeability, blood flow and time.
Formulation considerations with sublingual/buccal delivery
Human skin basic layers
epidermis, dermis, hypodermis/subcutis
Human skin system
integumentary
Skin function
retention of moisture and prevention of permeation, regulation body temp, protect from microbes, sensation
Epidermis
outer layer. stratified epithelium tissue - 5 layers. No blood vessels. gets nutrients through diffusion through dermis
Epidermis layers
stratum corneum (SC), stratum lucidum (lucid), stratum granulosum (granules), stratum spinosum (spine), stratum basale (base)
Cells in epidermis
keratinocytes, melanocytes (melanin), langerhan cells (immunity), merkel cells (touch)
Epidermal barrier structure
Brick (corneocytes) and mortar (lipids). penetration happens through lipids.
Cornification
Keratinisation
movement of keratinocytes up through epidermis to form rigid layer of keratin, microfilaments and microtubules
Desquamation
process of getting rid of dead skin cell layers from SC - 28 days
Corneocytes
tightly packed water resistant dead cells linked by junctions. contain natural moisturising factor (NMF)
Mortar
lipid material called
intercellular lamellar lipids
Epidermal barrier functions
Oxidative stress on skin
leads to damage contributing to aging, inflammation and disease. Skin has defense mechanisms to reduce this
Skin defense mechanism against oxidative stress
antioxidant enzymes and molecules, melanin, physical, repair mechanisms, detoxification
Main types of human skin
oily, dry, combination, normal, aging, sensitive
Oily skin
larger pores, shininess, sebum, acne prone
Dry skin
fine pores, matte, wrinkles (premature aging), compromised moisture barrier
Interaction of cosmetics on skin
absorption, penetration, skin barrier integrity, tolerance, sensitivity, moisture, hydration, surface effects, long-term benefits
Hair follicles
skin appendage. protect from sun, decrease friction, regulate body temp, sensory organ
Hair mechanism
arrector pili muscle contracts and expands to make the hair stand (eg goosebumps).
Hair structure
shaft (outside), root: cuticle, cortex, medulla. bulb at the root, papilla supplies blood
Penetration pathways through skin
transepidermal (first), transappendageal (second)
Transepidermal
large surface area of SC, drug penetrates in/between cells
Transappendageal
delivery through hair follicles or sweat glands necessary for polar or ionisable or large macromolecules, small absorption area
Transdermal delivery of molecules
drugs need specific solubility in water and oil and smaller size.
Transdermal patches
single or multi layer drug in adhesive. control release of drug that sticks to skin