Hydrolysis in vitro

G. K. E. Scriba, Phenytoin-Lipid Conjugates Chemical, Plasma Esterase-Mediated, and Pancreatic Lipase-Mediated Hydrolysis in vitro, Pharm. Res. 1993, 10, 1181 — 1186. 

Substituted Phenyl Diethyl Phosphates Rate of alkaline hydrolysis in vitro (35)... 

If sporulation is insufficient, the same procedure may be repeated with commeal agar or potato agar, which is sometimes successful. If this fails too, a number of additional tests exist for the identification of dermatophytes, including urea hydrolysis, in vitro hair perforation test, growth on polished rice grains, temperature enhancement or tolerance tests as well as numerous tests for the detection of special nutritional requirements, e.g. thiamine, niacin. 

The physiochemical properties of noladin ether (164) were successfully improved by introducing a phosphate moiety to the structure. High water solubility and chemical stability, together with a rapid quantitative enzymatic hydrolysis in vitro and the ability to reduce lOP in vivo, prove that the phosphate esters (165) and (166) are promising prodrug candidates of end-ocannabinoid noladin ether (Figure 26). ... 

The lipophihc Tc-HMPAO complex is transformed by hydrolysis (in vitro) to the secondary hydrophilic "Tc-HMPAO complex, which cannot cross the blood-brain barrier (BBB) when injected. Since a high extraction fraction is essential for quantitation of CBF, high radiochemical purity of lipophihc Tc-HMPAO is required. The average value of hpophihc Tc-HMPAO has been reported as 83% (Lassen et al. 1988) and 80.8% (Murase et al. 1992), respectively. Care has been taken to minimize the time between the quality control measurements and administration of the " Tc-HMPAO complex (Murase et al. 1992). 

Harris, L.W., Braswell, L.M., Fleisher, J.H., and Cliff, W.J., Metabolites of pinacolyl methylphosphonofluoridate (soman) after enzymatic hydrolysis in vitro, Biochem. Pharmacol., 13, 1129, 1964. 

The mechanisms by which the cofactors for degradation of glucosylceramide and galactosylceramide stimulate the respective enzymes is not yet known. Quantification of these cofactors by their capacity to enhance enzymic glycolipid hydrolysis in vitro must therefore rely entirely on practical experiences. These will be discussed with the respective assay systems. 

S ATP -I- phospholipase C y <60> (<60>, growth factor-induced tyrosine phosphorylation of PLC y is essential for stimulation of phosphatidylino-sitol hydrolysis in vitro and in vivo [191]) [191]... 

The analysis of heroin in biological specimens is difficult because heroin is rapidly metabolized in vivo and is subject to chemical and metabolic/enzymatic hydrolysis in vitro. In addition, the effective therapeutic dose of heroin is small owing to its high potency, and thus, biological fluid and tissue heroin concentrations are exceedingly low. Therefore, in order to quantify heroin accurately in tissues, adequate... 

Hydrolytic degradation can be assessed as noted above. Keep in mind, however, that in vivo hydrolytic attack is often accelerated or catalyzed by enzymes, local pH, and/or physiologic ions. Immersion in solutions containing an esterase, cholesterol esterase, and a protease has been shown to accelerate hydrolysis in vitro [34,35]. 

Karjalainen, T., Hiljanen, M., Malin, M. and Seppala, J. (1996) Biodegradable lactone copolymers. III. Mechanical properties of 8 caprolactone and lactide copolymers after hydrolysis in vitro, J. Appl Polym. ScL 59, 1299-1304. 

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