7. Nanocosmetics and nanomedicine for topical use Flashcards Preview

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Flashcards in 7. Nanocosmetics and nanomedicine for topical use Deck (35)
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1

Mention key details of the definition of a "nanomaterial" in EU regulations for cosmetic use.

  • one or more dimensions 1 - 100 nm
  • insoluble
  • biopersistent

2

What benefits may nanotechnology bring when used in cosmetics?

3

Mention 9 types of soft nanoparticles which may be used for topical use.

SLNP = solid-liquid nanoparticle

NLC = nanostructured lipid carriers.

4

  • Describe the anatomy of the skin.
  • Describe 7 functions of the skin.

5

Which 3 major transport routes exist in the skin?

  1. transcellular
  2. intercellular
  3. transappendageal

Note: Transappendageal route = transportation of drug via the sweat glands and the hair follicles. 

6

What is the largest challenge if you want to transport a drug across the skin?

The stratum corneum is the toughest permeability barrier.

7

Describe the anatomy of the stratum corneum, including sizes.

dead keratinocytes

tight lamellar lipid matrix

 

between layers: 70 nm

between keratinocytes: 36 nm

tickness of stratum corneum: 13.5 micrometers

8

What type of molecules are needed for the passive diffusion through the skin?

  1. small (NPs larger than 20 nm do not penetrate the skin)
  2. lipophilic
  3. non-charged

9

I have a hydrophilic substance that I would like to penetrate the skin. What could I try?

Using a vesicular lipid nanocarrier.

This may enhance the permeability through the skin by 2-3 fold.

10

How can you enhance drug delivery through the skin?

Disrupt the skin; either chemically or physically.

11

After skin poration, a NP may be delivered through the skin and being uptaken by a dendritic cell. Why would you want to target dendric cells (Langerhans cells) in the skin?

For delivery of vaccines and of drugs which interact with the immune system

After activation, the Langerhans cells initiate and shape the adaptive immune response.

 

12

Describe 3 different types of vesicular nanocarriers.

  • amphiphilic molecules (polar head, lipophilic tail)
  • conically shaped amphiphilic molecules  (with 1 tail) give micelles
  • cylindrically shaped amphiphilic molecules  (with 2 tails) give liposomes
  • conically shaped amphiphilic molecules  (small head, with 2 long tails) give inverse micelles

13

There are 3 types of surfactants. Which?

neutral, anionic, cationic

14

Mention 3 types of nanoemulsions.

  1. oil-in-water
  2. water-in-oil
  3. bi-continuous

15

Mention 4 benefits of nanomicelles and nanoemulsions.

  1. ease of preparation
  2. solubilisationof poorly soluble drugs
  3. enhanced permeability through the skin
  4. stability (low thermadynamically stable but highly kineticically stable)

16

Mention 4 methods for the production of nanoemulsions.

High energy:

  1. high shear homogenisation
  2. sonication

Low energy

3) emulsion inversion point (EIT)

4) phase inversion temperature (PIT)

17

Give an example of a bi-catenar system.

catanionic self-assembled vesicles.

18

Mention 3 types of liposomes.

  1. SUV (small unilamellar vehicles)
  2. LUV (Large unilamellar vehicles)
  3. MLV (multilayer vehicles)

 

Note: there is a mistake on the slide for LUV.

19

Describe methods of liposome production.

20

What are niosomes, and what are they used for?

Non-ionic surfactant-based vesicles.

They fuse and mix with the lipids of the stratum corneum; delivery of relativeky large molecules across the skin.

21

I added an edge activator to my liposomes. What happens?

The fluidity of the lipid bilayer enhances.

22

  • What are the differences between niosomes and liposomes (5)?
  • Which use do they have in common?

23

"New generation" liposomes have been developed. Name and describe these. Mention how they differ from liposomes.

24

  • What is a Pickering emulsion?
  • What can you use it for?

25

What type of NPs can you use for a Pickering emulsion?

  1. clay
  2. silica
  3. metal oxides (ZnO, CeO2, TiO2)
  4. nanocellulose
  5. protein

26

What is the stabilising factor of NPs in pickering emulsions? 

Energy of attachment depends on R2, surface tension (gammaow), and the contact angle (theta).

27

Mention 4 important characteristics of a NP for forming Pickering emulsions.

  1. particle size
  2. shape
  3. hydrophobicity
  4. contact angle

28

What are the properties, benefits, and limitations of solid lipid NPs?

29

How do you produce solid lipid nanoparticles (SLPs)?

melting - nanoemulsion - cooling - crystalisation

30

What are nanostructured lipid carriers?