Formulation development emulsifier

Kommuru, T.R., Gurley, B., Khan, M.A., Reddy, I.K. (2001). Self-emulsifying drug delivery systems (SEDDS) of coenzyme Q10 formulation development and bioavailability assessment. International Journal of Pharmaceutics, 212, 233-246. 

Singh, B., Bandopadhyay, S., Kapil, R., Singh, R., Op, K., 2009. Self-emulsifying drug delivery systems (SEDDS) formulation development, characterization, and applications. Grit. Rev. Ther. Drug Carrier Sys. 26, 427—521. 

Hydrosilation reactions have been one of the earlier techniques utilized in the preparation of siloxane containing block copolymers 22,23). A major application of this method has been in the synthesis of polysiloxane-poly(alkylene oxide) block copolymers 23), which find extensive applications as emulsifiers and stabilizers, especially in the urethane foam formulations 23-43). These types of reactions are conducted between silane (Si H) terminated siloxane oligomers and olefinically terminated poly-(alkylene oxide) oligomers. Consequently the resulting system contains (Si—C) linkages between different segments. Earlier developments in the field have been reviewed 22, 23,43> Recently hydrosilation reactions have been used effectively by Ringsdorf 255) and Finkelmann 256) for the synthesis of various novel thermoplastic liquid crystalline copolymers where siloxanes have been utilized as flexible spacers. Introduction of flexible siloxanes also improved the processibility of these materials. 

The adjuvanticity of oil emulsions was first recognized in the early 1900s. However, the first such product to gain widespread attention was Freund s complete adjuvant (FCA), developed in 1937. This product essentially contained a mixture of paraffin (i.e. mineral) oil with dead mycobacteria, formulated to form a water-in-oil emulsion. Arlacel A (mannide mono-oleate) is usually added as an emulsifier. 

Pentaerythritol Ester As with glycerol esters, the esters are produced by esterification of pentaerythritol with the desired fatty acids. For example, under defined reaction conditions and use of stearic acid in defined concentration, pentaerythritol distearate has been recently developed as an off-white wax with very weak odor (Cutina PES). This type of product is offered as co-emulsifier and consistency factor for cosmetic products with high sensorial elegance and can be applied in various formulations (Fig. 4.17). 

An expert system has been written which helps the agricultural chemist develop formulations for new biologically active chemicals. The decision making process is segmented into two parts. The first is which type of formulation to use. The second is how to make a formulation of that tyrpe with the chemical of interest. The knowledge base currently contains rules to determine which formulation type to try and how to make an emulsifiable concentrate. The next phase will add rules on how to make other types of formulations. The program also interfaces to several FORTRAN programs which perform calculations such as solubilities. 

Agricultural (Ag) formulations that are commonly diluted and applied by means of spray equipment include water soluble liquids, emulsifiable concentrates, wettable powders, and flowable suspensions. The choice of which formulation to develop normally depends upon the solubility properties of the technical pesticide. Scientists often must also consider manufacturing costs, field efficacy and product toxicity. 

Colorado potato beetle, diamond back moth, pear psylla, and Liriomyza leafminers can be achieved at extremely low application rates of MK-936 in the range of 0.005-0.03 lb per acre (5.5 - 33 g per hectare). For foliage applications a 0.15 EC (1.8% w/v) emulsifiable concentrate formulation has been developed. Field studies have shown that the formulation is non-phytotoxic to all target crops on which it has been evaluated including many varieties of sensitive ornamental plants. 

Our laboratory partnered with Josephine Bissing Dermaceuticals of Denver, CO, to develop delivery systems for certain skin care formulations that would eliminate the needs for surfactants, stabilizers, and emulsifiers. In effect, the hydrophilic polyurethane matrix in which the skin care formulation resides would replace all the stabilizing chemicals typically used in such formulations. 

DDT is available and used in different formulations (e.g., aerosols, dustable powders, emulsifiable concentrates, granules, wettable powders). It is used mainly to control mosquito-borne malaria. Its use on crops has decreased because of its persistent residues. DDT was extensively used during World War II among Allied troops and certain civilian populations to control insect typhus and malaria vectors, and was extensively used as an agricultural insecticide after 1945. DDT was banned for use in Sweden in 1970 and in the United States in 1972. In view of its large-scale use over the decades, many insect pests may have developed... 

Phosphate esters are widely used in metalworking and lubricants. A C12 h with 6 mol of ethylene oxide (diester) can be used as an emulsifier but also as an extreme pressure additive - it can reduce wear where there is high pressure metal to metal contact. PEs can also show corrosion inhibiting properties, as with petroleum sulphonates and the emulsifying power of PEs with low foam is used in agrochemical formulations. PEs can act as dispersants or hydrotropes in plant protection formulations, allowing the development of easy-to-handle and dilute formulations of both poorly miscible and insoluble herbicides. 

In some areas, for example in crop protection, moving away from solvents simply required the development of new forms of delivery, e.g. concentrated emulsions or suspo-emulsions progressively displaced the emulsifiable concentrates. A change in the surfactant system was obviously necessary, but the new formulations could be made using commercially available products. In other instances, for example in the field of emulsion polymers, new colloidal species were developed and are still the subject of extensive research the reactive surfactants. 

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