Nanotechnology Flashcards
What is the size range of nanoparticles?
10-1000nm
What are the three types f Nanotechnology based DDS
Polymer based nano
Nanoemulsions
Solid lipid nanoparticle
What are polymer based nanoparticles
polymeric colloidal particles which a therapeutic agent can be embedded or encapsulated in the polymer matrix
Nanocapsule vs Nanosphere
Where is the drug located?
Nanocap: Drug is in reservoir in nanoscale and it is encapsulated in the membrane
Nanosphere: drug is dispersed in polymer matrix
What is the classification of polymers used in nanoparticles
Natural or synthetic
Synthetic can be either biodegradable or non biodegradable
Natural are always biodegradable
E.g. of naturally occuring biodegradable and biocompatible polymers
Cellulose
Gelatin
Chitosan
Crabshell ( biocompatible)
e.g. of synthetic biodegradable
Polylactic acid
Poly-(lactide-co-glycolide)
Polyanhydrides
Poly-alkyl-cyanoacrylate
Non biodegradable synthetic polymers
polystyrene (used only for diagnostic imaging purpose)
What are Methods of preparation of polymer based nanoparticles?
(they are versatile)
Solvent evaporation method (emulsion solvent evaporation method)
Ionotropic gelation
Explain the solvent evaporation method
How do to prepare polymer?
Drug is dissolved where?
After the emulsion is formed, kif it is converted to nanoparticle?
Preparation of polymer solution in volatile solvent
Drug is dissolved in solution and the organic phase is emulsified under agitation in dispersing phase which contains a suitable emulsifying agent
The emulsion is then converted into nanoparticle suspension on evaporating the solvent
E.g. of volatile solvents
dichloromethane
chloroform
ethyl acetate
They should easily evaporate at <40 degrees
In solvent Evaporation Method:
Aqueous phase is what?
Organic phase is what?
Step one is what?
Step two is what?
Aqueous phase is o/w e.g. tween + water
Organic is oily phase
Step one is emulsification
Step 2 evaporation while stirring continuously
(ppt solid nanoparticle and colloidal dispersion)
Explain Ionotropic gelation Method
What does it involve?
Involves the addition of alkaline tripolyphosphate (TPP) solution (pH=7-9) into acidic chitosan solution pH= 4-6
What is the method of synthesizing hydrogel NPs using polymers like chitosan, and what is the significance of the presence of NH2 groups in these NPs?
Polymers such as chitosan produce hydrogel NPs
They are synthesized by Ionotropic method
Contains NH2 that will be protonated
Ionotropic Method in pictures
Chitosan is dissolved in acetic acid tp lead catanionic group
Drug is dissolved in this solution after chitosan formation
Addition of TPP (-ve charge) drop wise while stirring cont. to avoid ppt of two opp charges
What are nanoemulsions
o/w Non ionized oily globules
Also known as submicron emulsions, Ultrafine or mini emulsions
They are Submicron sized colloidal particulate Systems
(we use lipophilic drugs)
What drugs do nanoemulsion deliver? What do they serve as? What do they do to bioavailability
Serve as aqueos dosage form of water insoluble drugs
Deliver lipophilic drugs after solubilization
Enhance bioavailability
What are the techniques used
High pressure homogenization
Micro fluidization
Ultrasonication
What is High pressure Homogenization
A mixture is forced to pass through an orifice at very high pressure
The result product is further subjected to intense turbulence and impaction forces resulting in emulsion with extremely fine particles
For 10-1000nm
What is the only drawback of High Pressure Homogenization
The rise in temperature of emulsion during processing
Thus it is not good for heat labile drugs
what is the solution for high temperature in HPH
Use ice bath (water jacketed)
Factors affecting size
Surfactant
Drug
Oil
Ratio of o to w
The process can be repeated to achieve results
What is Microfluidization
It utilizes a high pressure pump
Products are pushed out through the interaction chamber
The chamber consists of stainless steel microchannels
The impingement area results in the formation of small particles
The particles are of submicron size
What is the advantage of microfluidlization to high pressure?
F 3anda cooling coil
Ultrasonication technique
Hiye 3ibara 3an shu
How is the size of particles reduced?
emulsion is exposed to agitation at ultrasonic frequency of 20 kHz
Reduces droplets to nanodroplets
Produces mechanical vibration when the sonicator tiip contact with liquid
Leads to cavitaion thus size reduction
Solid Lipid Nanoparticles definition
The oil of fat emulsion is replaced by solid lipid
Examples of Solid lipids
glyceryl monostearate
Stearic acid 3ando more sustained effect and more stable
Tristearin
What is the process of forming solid lipid nanoparticles
1- Lipid is melted
2 Lipophilic drug is added to lipid emulsion
3- Prepare aqueous phase (H2O + Emulsifying agent)
4-Heat the aqueous phase at high temp
5- Dispersing the lipid in aq phase
6- Homogenization
7- Ultrasonication of the emulsion
8- Formation of colloidal emulsion
9- Upon cooling with continuous stirring, solid lipid nano are formed
10- They can undergo centrifugation to collect the nanoparticles
In Solid lipid nanoparticles, why is homogenization done ultrasonication
To yield small nanoparticles
