Toxicants, systemic

The inorganic tin compound that has received the most study from a toxicological viewpoint is stannic oxide. Autopsies performed on workers in the tin mining and refining industry, who inhaled tin oxide dust for as long as 20 yr, disclosed no pulmonary fibrosis (57). Inhalation for long periods produces a benign, symptomless pneumoconiosis with no toxic systemic effects (58). 

Bugrim A, Nikolskaya T, Nikolsky Y. Early prediction of drug metabolism and toxicity systems biology approach and modeling. Drug Discov Today 2004 9 127-35. 

The priority effects are carcinogenicity, mutagenicity, reproductive or developmental toxicity, endocrine disruption and neurotoxicity. Human toxicity is broader than priority effects, including acute toxicity, systemic toxicity (organ effects), immune system effects and skin/eye/respiratory damageaswellasthepriority effects. And toxicity as T includes both human toxicity and ecotoxicity. 

Current guidelines for toxicity evaluation of ophthalmic formulations involve both single and multiple applications, dependent on the proposed clinical use [39]. The multiple applications may extend over a 9-month period and incorporate evaluations of ocular irritation and toxicity, systemic toxicity, and determinations of systemic exposure (toxicokinetics). In many cases the systemic exposure from an ocular route is less than by parenteral administration, information that will assist in determining whether additional studies may be needed to establish systemic safety of the ophthalmic preparation. U.S. and international guidance documents are available [71,72], and regulations and tests have been summarized for ophthalmic preparations [39,73,74],... 

The concentration of the highly toxic systemic insecticide thiometon in work zone air with both air- and tractor-based spraying reached 2.3 mg/m3 (with a standard of 0.1 mg/m3) [All]. In fact, concentrations in the air when... 

An in vitro toxicity system is made by three components ... 

In vitro developmental toxicity systems have clearly been usefid for studies of mechanisms of developmental effects (e.g., Datson et al., 1989) — use (3) in the list above. It is unclear, though, whether in vitro developmental toxicity tests will provide useful information about developmental toxicity that is not derived from whole animal studies [use (4) from the list]. As is true for a possible use as a prescreen, the interpretation of a positive finding in an in vitro test will depend on knowing the exposure level in vivo. When this is known, the in vitro information could be helpful. The results of in vivo studies, though, would still likely be considered definitive for that species. 

Agents for chemical disinfection ideally should cause rapid, complete, and persistent inactivation of all germs, but at the same time exhibit low toxicity (systemic toxicity, tissue irritancy, antigenicity) and be non-deleterious to inanimate materials. These requirements call for chemical properties that may exclude each other therefore, compromises guided by the intended use have to be made. 

As an oral rinsing agent, to date chlorhexidine has not been reported to produce any toxic systemic effects. Since chlorhexidine is poorly absorbed in the oral cavity and gastrointestinal tract, little if any enters the bloodstream. A summary of chlorhexidine oral rinses is given in Table 42.1. 

Sax (Ref 10) considers the sulfate as a moderate local irritant, a highly toxic systemic poison by ingestion and a dangerous disaster hazard if heated to decompn... 

The Secondary Heat Transfer Fluid Circulation module meets the heat transfer needs of the processes carried out in the Neutralization module. There are three identical units in the Secondary Heat Transfer Fluid Circulation Module. Each unit serves one of the three identical neutralization unit toxic cubicles. The Secondary Heat Transfer Fluid Circulation Module provides a boundary between toxic systems and the environment and prevents contamination of plant cooling water by toxic process fluids in the event of heat exchanger leaks. 

Surfactants have been the most investigated chemicals to promote drug absorption from all body tracts. In this section, we will focus on work carried out from the early stages on the enhancing effects of surfactants on drug GI absorption as well as on their interactions with the GI membrane and their toxicity. Systems with multifactorial effects such as emulsions and microemulsions are not the focus of this review. 

Batch crystallizers can be used in a campaign to produce a particular product and in a second campaign to produce another product. Generally, it is not possible to operate continuous processes in this way. Batch crystallizers can handle viscous or toxic systems more easily than can continuous systems, and interruption of batch operations for periodic maintenence is less difficult than dealing with interruptions in continuous processes. The latter factor may be especially important in biological processes that require frequent sterilization of equipment. Batch crystallizers can produce a narrow crystal size distribution, whereas special processing features are required to narrow the distribu-... 

Toxicity System GA System GK Molecular Base peak... 

Bacsik CJ, Swift JQ, Hargreaves KM. Toxic systemic reactions of bupivacaine and etidocaine. Oral Surg Oral Med Oral Pathol Oral Radiol Ended 1995 79(l) 18-23. 

The eye is not, of course, a general route for the administration of drugs to the body, although it has been explored for the systemic delivery of peptides and proteins such as insulin. It is considered here because absorption of drugs does occur from medication applied to the eye, producing sometimes toxic systemic effects, although often the desired local effect is on the eye or its component... 

Anesthesia of the mucous membranes of the ear. nose, and throat is usually brought about by use of aqueous solutions of the. salts of tetracaine, lignocainc. or cocaine. The vasodilator effect of cocaine reduces bleeding in surgical procedures. However, all local ane.sthetics are rapidly absorbed through mucoas membranes, and so their ase may be accompanied by an increa.scd risk of toxic. systemic reactions. As a result, dosage must be carefully controlled. 

Local versus systemic toxicity Local effects refer to those that occur at the site of first contact between the biological system and the toxicant systemic effects are those that are elicited after... 

Ray DE (2001) Pyrethroid insecticides Mechanisms of toxicity, systemic poisoning syndromes, paraesthesia, and therapy. In Kreiger R (ed.) Handbook of Pesticide Toxicology, Chapter 59, pp. 1289-1303. New York Academic Press. 

Because the preparation of a w/o/w system is a two-stage procedure, it is possible to modify either the primary aqueous phase (which becomes the internal aqueous phase of the multiple system) or the secondary aqueous phase, which subsequently becomes the continuous aqueous phase. Each aqueous phase can be gelled by in situ polymerization reactions. Polyacrylamide has been used to demonstrate the technique, but less toxic systems are required for pharmaceutical use. 

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