Steps of Downstream Processing
Downstream processing is the purification of pharmaceutical products fromnatural source, for example plant and animal tissue. The following are stages followed in the processing
Stage one: removal of insoluble (solid and liquid separation)
This step involves separation of whole cells that is cell biomass and other insoluble. It is important to note that the release of intracellular metabolite must be done before the separation of solid and liquid during downstream processing
There are several methods which are used in the separation of liquid and solid which include; floatation, flocculation, filtration and centrifugation.
Step two: release of intracellular products
A cell contains biotechnological products which are vitamins and enzymes. These products have to be released maximally for further processing and final isolation. Disintegration of cells or other microorganisms can be done by chemical, physical and enzymatic methods
Step three: concentration
This is the removal of components that vary considerably from the desired products. In this case water is the required impurity that is needed to be isolatedin order the material to concentrate the product.
The following are the most common used techniques used in concentrating biological products which include: adsorption, membrane, filtration, liquid to liquid extraction, evaporation and precipitation. The nature of the material used in downstream processingdetermines the technique to be used
Step four: purification by chromatography
Chromatography is used to purify biological products of fermentation which include; pharmaceutical, diagnostic compounds and proteins. It is a technique used in separation of closely related compounds in a mixture.
This stage is expensive to execute and requires sophisticated equipment. There two phases of chromatography namely; stationary and mobile.
Success has been achieved after integrating the required stages in downstream processing for purification.
Stage five: formulation
This is the stability of biotechnological products between the period of storage and distribution. Removal of water in the product through concentration helps in achieving the formulation of low molecular weight of the product for small molecules such as citric acid and antibiotics can be formulated.