Solubilization drug concentration

Emulsions are either oil phase dispersed in water phase, an oil-in-water (o/w) emulsion, or water phase dispersed in oil phase, a water-in-oil (w/o) emulsion. If a poorly water-soluble drug substance is soluble in oil, it can be solubilized in an emulsion where it partitions into the oil phase. The total solubility in an emulsions, is the summation of concentrations in the aqueous and oil phases (Strickley, 2004). The total solubility of the emulsion system is the sum of the drug concentration in the aqueous phaseSv, and the concentration in the oil phase, which can be approximated by the product of the drug s solubility in the pure oi i, multiplied by the fraction of the oil in the emulsion ... 

Not withstanding the use of nanoparticles for intravenous and topical applications, improvement in oral bioavailability is one of the most important contributions attained through nanotechnology. Molecules that are poorly water soluble may be poorly absorbed because of a lack of sufficient concentrations of solubilized drug. Formulations that are amorphous can overcome this by supersaturation of the dissolution medium allowing for greater absorption of the delivered dose. However, stability problems are significant for... 

One practical use of a buffer is to simply maintain the pH of the system over time. For pH solubilized drugs, another practical use of a buffer is to reduce or eliminate the potential for precipitation of the drug upon dilution. It has been shown that drug precipitation upon intravenous injection has been linked to phleb-itis.f As shown through the previous discussion, the solubility of a drug can be increased exponentially with pH alteration. However, it also then follows that the solubility can decrease exponentially with pH alteration. If a pH solubilized formulation is diluted with a medium by one half, then the drug concentration will... 

Calculate the amount of cyclodextrin-solubilized drug spectro-photometrically, by measuring its absorption at 256 nm, and constructing an appropriate calibration curve, ftom solutions of known drug concentration. 

Water-miscible surfactant molecules contain both a hydrophobic and hydrophilic portion, and can solubilize many poorly water-soluble drugs. Surfactants can also self-assemble to form micelles once the surfactant monomer concentration reaches the critical micelle concentration. Thus surfactants can solubilize drug molecules by either a direct cosolvent elfect or by uptake into micelles. The non-ionic surfactants in commercially available solubilized oral formulations include polyoxyl 35 castor oil (cremophor EL), polyoxyl 40 hydrogenated... 

Although co-solvent use is a successful method of improving drug/excipient solubilization in aerosol systems, there are limitations to this technique. Simply increasing the drug concentration in a formulation does not guarantee an increase in the total amount of respirable drug delivered. 

Water-borne Administration. For the waterborne route of exposure, drug solubility in water is a major concern. Use of sonication, warming, salt formation, dilution and carrier vehicles may facilitate dispersal of sparingly-soluble drugs into water-based stock solutions. Whenever possible, the drug should be added directly to dilution water without carrier solvents. Dimethylformamide, ethanol and acetone, can be used to facilitate solubilization if concentrations of the carrier do not exceed 0.01% of the final dilution water. 

In a further study, the authors demonstrated that the Ql phase can solubilize high concentrations of the water-insoluble anti-inflammatory drug sodium diclofenac (Na-DFC) [40]. Up to 0.4 wt% Na-DFC, the Ql structure remained intact... 

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