Stability gastrointestinal tract

Their low metaholic stability toward proteolysis in the gastrointestinal tract and in serum. 

Rectal Avoids problems of stability in gastrointestinal tract No first-pass metabolism Useful if oral administration is not possible Unpopular Inconvenient Erratic absorption Irritation Suppositories, enemas (solutions, suspensions, emulsions), foams, ointments, creams... 

Mushroom poisoning requires serious medical intervention because muscarine absorbs well in the gastrointestinal tract, and therefore it can lead to death. Muscarine is considerably more powerful than acetylcholine, possibly because of its high stability. Because it is... 

Knowing the differential pharmacokinetics for a class of drugs allows the clinician to choose specific members to either achieve a faster onset or a delayed offset of action (13, 14, 17, 18). For example, lorazepam is rapidly absorbed from the gastrointestinal tract into the systemic circulation and from there distributed into the brain. In contrast, oxazepam, the most polar BZD, is slowly absorbed from the gastrointestinal tract. Even after oxazepam is in the systemic circulation, it slowly enters tissue compartments, including the brain, during the distribution phase. Unlike lorazepam, oxazepam is not available in either the intramuscular or intravenous formulations. Thus, lorazepam would be preferable to achieve acute control of alcohol withdrawal (e.g., delirium tremens), whereas oxazepam would better stabilize a dependency-prone patient on sedative-hypnotics, because it does not cause the euphoria seen with the more rapidly absorbed members of this class. 

Decontamination procedures should be undertaken simultaneously with initial stabilization, diagnostic assessment, and laboratory evaluation. Decontamination involves removing toxins from the skin or gastrointestinal tract. 

Table 2.1 presents examples of the main classes of low-molecular-weight bioactive molecules which are currently considered to be helpful for human well-being and which can be therefore used as food supplements as well as active components in skin-care applications (Ratnam et al., 2006 McClements et al., 2009). The required physicochemical properties of effective bioactive compounds, which should be considered in the formulation of the prophylactic and therapeutic dietary supplements at their desired oral dosages, are described in the scientific literature. These properties are (i) solubility in aqueous media (ii) permeability through the gastrointestinal tract and cell membranes (iii) physical stability and (iv) bioavailability. 

Mesitylene. One of the principal derivatives of mesitylene is the sterically hindered phenol of the structure shown in Figure 4. Its trade name is Ethanox 330 and it is produced by Albemade Corporation (formedy Ethyl Corporation) (31). Ethanox 330 is an important noncoloring antioxidant and thermal stabilizer for plastics, adhesives, rubber, and waxes (qv) (32,33) (see Antioxidants). The oral toxicity of Antioxidant 330 is extremely low (oral 1D. in rats > 15 g/kg) since its large size, Cc4H7 0, effectively eliminates absorption from the gastrointestinal tract. 

One of the biggest impediments of oral administration of macromolecules is their lack of stability in the gastrointestinal tract. Indeed, the majority of macromolecules such as peptides, proteins, oligonucleotides, and various types of RNA undergo enzymatic degradation before reaching their site of action or absorption. One of the strategies used to circumvent this problem is to incorporate such compounds into nano- or microcarriers. These carriers... 

Drug properties that are important to consider during development of IR tablets are metabolism, stability, permeability, and solubility [18,19]. In the development of ER formulations, these aspects are also important, but in addition to IR formulations, they must be considered in relation to the different environments that the ER formulations meet during their passage through the gastrointestinal tract, and some of these aspects will be discussed briefly below. It can be mentioned that, based on these initial properties for drug candidates, Thrombre has constructed a feasibility assessment flow chart for ER formation development [18]. 

The stability of the divalent state of zinc is such that it acts neither as an oxidizing nor as a reducing agent under the physiological conditions of the mammalian gastrointestinal tract. 

Reports dealing with the technical application of polymeric AO are concerned mostly with aromatic amines. Excellent results in the stabilization of SBR or NBR articles in engineering applications were obtained with Chemigum HR (86) [77]. Oligomeric 2,2,4-trimethyl-l,2-dihydroquinoline (100) has been used successfully for many years in stabilization of vulcanized rubbers. Both 86 and 100 are efficient AO. The imporance of the application of polymeric phenolic AO for the stabilization of packaging materials for foods may be exemplified [114] The absorption of Poly AO-79 (97) in the gastrointestinal tract was studied with relationship to the M of the AO ... 

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