Jet Stream Homogenization Method

Total surface area 6cm² Total surface area 12cm² Total surface area 24cm²

Fig.2. Surface area is inversely proportional to particle size

Methods of preparations:
There are different methods involved in preparation of nanocrystals. But all of them uses either of these basic principles. Milling method, precipitation method, homogenization method and their composites. Generally used methods for preparations are:
1) Bottom up technique
2) Top down technique
Pearl/ball milling
High pressure homogenization
Micro fluidizer technology
Piston gap homogenization in water
Piston gap homogenization in non-aqueous

The principle involved in this process is jet stream. Jet stream homogenizers uses the same principle e.g. micro-fluidizer. Collision chamber designed is either Y- type or Z- type(C). Stabilizers such as surfactants or phospholipids are necessary for controlling the desired particle size. This method is not very convenient for large scale production but still can be used for production of soft drugs. SkyePharma Canada Inc. uses this process for production of submicron particles of poorly soluble drugs

This process takes place in a conical or cylindrical cyclone, solutions of drug Nano suspensions produced by HPH are sprayed feed from the up to down, even hot air is applied from the same direction and spherical shape particles are obtained. Polymers, sugars or sugar alcohols like mannitol or sorbitol are water soluble matrix which are used for drug Nano suspension formulation. Atomizer is used for spraying which rotates rapidly and due to the centrifugal effect scattering to the solution takes place. Nitrogen gas or air at constant pressure are applied via outer tube. Spraying can be done by nozzle which leads to very small particles i.e. surface area increases leading to fast drying. Particle size, fluidity and drying speed can be optimized and viscosity, temperature and spray rate of the solution should be maintained. The nanocrystals formed are filled into hard gelatin or sachets or tablets for further use. (A, C). Freeze drying
This process is used for removal of water from the complex. Method involves mixture of drug solvent together with mannitol is cooled rapidly, leads to separation of drug in nanocrystals form enclosed by a matrix of mannitol which decreases the instability of the Nanocrystalized drug i.e. prevents from sticking to each other. Other methods used for drying are spray freeze drying and lyophilization(C).