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Formulation Development of Small-Volume Parenteral Products
Published in Sandeep Nema, John D. Ludwig, Parenteral Medications, 2019
Madhav S. Kamat, Patrick P. DeLuca
Use of Cosolvents: If the pH adjustment or salt formation approach still results in aqueous solubility of a drug well below its therapeutic dose, a mixture of solvents may be used to achieve sufficiently high solubility. A cosolvent is a water miscible organic solvent that is used to increase the solubility of a poorly water-soluble compound. The addition of cosolvent results in reduction of polarity of water which in effect reduces the surface tension, DC, and solubility parameter of water. The increase in solubility by cosolvents is much more dramatic for nonpolar solutes (can be several orders of magnitude) than for solutes of intermediate polarity. Another advantage of using cosolvents is that a change in solvent property may help considerably in stability for drugs which may exhibit hydrolytic degradation by reducing the concentration of water in the formulation. Cosolvent may also enhance the stability of a drug by providing a less suitable environment for the transition state of the reactants, provided the transition state is more polar than the reactants. It is reported that cosolvents are employed in approximately 10% of the FDA-approved injectable products [22].
Waterborne Coatings
Published in Ole Øystein Knudsen, Amy Forsgren, Corrosion Control Through Organic Coatings, 2017
Ole Øystein Knudsen, Amy Forsgren
Waterborne coatings always contain some organic solvent (cosolvent), typically in the order of 5%– 10%. The cosolvent tends to be low-molecular-weight ketones, alcohols, and esters. Their function in the paint is to help the film formation process.
Development of nanoparticles for pharmaceutical preparations using supercritical techniques
Published in Chemical Engineering Communications, 2022
Tariqul Islam, Abdullah Al Ragib, Sahena Ferdosh, A. B. M. Helal Uddin, Md. Jahurul Haque Akanda, Md. Abdur Rashid Mia, Reddy Prasad D. M, Bin Yunus Kamaruzzaman, Md. Zaidul Islam Sarker
Highly soluble active ingredients and polymers in CO2 are permitted to form the particles in the RESS process. When CO2 is directly utilized to dissolve the solid ingredients in the RESS process, any extra solvent or cosolvent is not applied in this approach. A cosolvent is used to improve the solubility of hydrophilic ingredients in the RESOLV and RESS-N process (Sun 2002; Meziani et al. 2005; Soh and Lee 2019). A solid cosolvent is utilized to dissolve the active ingredient and polymer in the RESS-SC process (Dixon et al. 1993; Thakur and Gupta 2005). In the SAS, GAS, SAS-EM, and SEDS processes, an organic solvent is used to dissolve the polymer and active ingredient. In the SEDS process, the sample solution and scCO2 are concurrently carried into the precipitating compartment using a coaxial nozzle at the same time (Gupta and Chattopadhyay 2002; Montes et al. 2011; Xie et al. 2015; Lee et al. 2019). Nanosized particles of some specific ingredients (carotenoids) can’t be made by the SAS-EM and SEDS method. In SEDS-EM, those ingredients are premixed with scCO2 in a coaxial nozzle, then produce NPs (Jin et al. 2011). An organic solvent and cosolvent (H2O) are used in the SFEE process. Firstly, the solvent is dissolved in key ingredients and polymer. This approach is also applied in amorphous polymers (Furlan et al. 2010). To get the nano-sized particle, some parameters and outputs have been tabulated from the literature at the end of the method discussion.
Improving heterogeneously catalyzed transesterification reaction for biodiesel production using ultrasound energy and petro-diesel as cosolvent
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
From, the above results it was clear that application of ultrasound energy enhances the rate of heterogeneously catalyzed transesterification. However, the increase in product yield was not significantly high in comparison to the conventional mechanically stirred process. Thus, to enhance the mass transfer and thus the reaction rate and yield, the researchers studied the ultrasound-assisted heterogeneously catalyzed transesterification reaction in the presence of cosolvent. As discussed in introduction section, a cosolvent helps in homogenizing alcohol and oil mixture which favors the reaction and enhances the product yield. After determination of optimum reaction conditions (given in table 1), the catalysts were studied for the effect of addition of cosolvent (10, 20, and 30 wt.% with respect to oil) under those conditions. The results of the study are shown in Figure 5a, 5b and 5c. The graph clearly suggested a remarkable improvement in product yield upon addition of cosolvent affirming the literature reports. There was an increase in product yield with increase in cosolvent concentration. In case of CSS, addition of 10% cosolvent was sufficient enough to bring about an yield as high as 97% in 120 minutes. Higher cosolvent concentration was more effective upto 90 min of reaction time but after that, the yield of biodiesel was the same as that of 10% cosolvent. This could be attributed to the fact that with the increase in reaction time the concentration of methanol decreased and with higher ratios of cosolvent the solution became very diluted and resulted in further decrease of methanol concentration. This in turn lowered the reaction possibility.