2.1 Classification of surface active agents.
The widely used synthethic surfactants in pharmaceuticals are classifieds as according on their surface charges.
1.Anionic surfactants:sodium alkyl sulfonates .SDS,SLS.
2.Cationic surfactants:Quaternary ammonium chlorides (quats),pyridinium salts .
3.Zwetterionic (amphoteric) surfactants:phospholipids- Phosphatidylcholine (Lecithin).
4.Nonionic surfactants: spans( esters of sorbitol with oleic acid),polysorbates(esters of sorbitol condensed no.of ethylene oxide units),poloxamers (copolymers of hydrophilic poly-oxyehylene and hydrophobic poly-oxypropylene) also called as pluronics.
Figure1-Structures of synthethic surfactants …show more content…
4.Polymer biosurfactants –manoproteins,liposan,emulsion and polysaccrides –proteins complex.
5.Particular biosurfacatnts-extracellular portion of membrane vesicles of hydrocarbon ,sometimes useful in substrate uptake by microbes as by forming microemulsions. (ref-Gharaei et al.2011)
3.2 Useful features of biosurfactants in pharmaceutical drug delivery systems.
1. Biosurfactants can be obtained by microbial ,enzymatic and by chemical synthesis methods from renewable resources.
2. They have low CMC value as compare to synthetic surfactants ,its mean that low concentration required to brought in reduction of ST.
3. They are environmental friendly option and they are also readily biodegradable .
4. Biosurfactants have low toxicity than the chemically synthetic surfactants ,it was reported that the biosurfactants show high EC 50 (effective concentration to decrease 50%of test population).
5.Biosurfactants production can be done by cheap raw materials sources like soyabeen, sunflower, molasses and fruits wastes.
6.They have surface activity,thermally stable at high temperature upto 50°C and also stable at wide range of pH (4-9)