SUBJECTS thymol

Aromatic compounds in the presence of alkali halides or solutions of halogen acids are usually substituted when subjected to electrolysis. Phenols are readily substituted, and several antiseptics have been obtained in this manner. Prom thymol in alkali solution, and in the presence of... 

Soluble starch, available from chemical supply houses, is readily dispersed in water. The iodine-starch complex has limited water solubility, and it is therefore important not to add the starch indicator until near the end point when the iodine concentration is low. Because starch is subject to attack by microorganisms, the solution usually is prepared as needed. Among the products of hydrolysis is dextrose, which can cause large errors because of its reducing action. Various substances have been recommended as preservatives, including mercury(II) iodide and thymol. With formamide a clear solution containing 5% starch is obtained that is stable indefinitely. 

Halothane (fluothane Figure 13-3) is a volatile liquid at room temperature and must be stored in a sealed container. Because halothane is light-sensitive and subject to spontaneous breakdown, it is marketed in amber bottles with thymol added as a preservative. Mixtures of halothane with oxygen or air are neither flammable nor explosive. 

Halothane produces rapid onset and recovery from anesthesia with high potency when used alone or in combination with nitrous oxide. Most metals, with the exception of chromium, nickel, and titanium, are easily tarnished by halothane. Although halothane is relatively stable, it is subject to spontaneous oxidative decomposition to hydrochloric acid, hydrobromic acid, and phosgene. For this reason, it is available in dark, amber glass containers with thymol added as a preservative to minimize decomposition. Halothane may permeate into the rubber components of the anesthetic delivery devices, which might account for some slowing of the induction onset and recovery. Approximately 20% of an administered dose is metabolized, which accounts, in part, for the increased hepatotoxicity observed with this agent (Fig. 18.7). 

After daily exposures to CS for 10 days, seven subjects had no alterations in blood sodium, potassium, alkaline phosphatase, or bromsulfophthalein one of the seven had an increase in thymol turbidity. No chest radiograph or urinary changes were seen.4 In another study,5 although significant changes were seen in some blood chemistries after exposure, all values were within the normal range. 

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