Intestinal juice

A summary of how physiological factors affect the dissolution rate is given in Table 21.2. The effective surface area will be affected by the wetting properties of the bile acids and other surface-active agents in the gastrointestinal tract. The dif-fusivity of a drug molecule in the intestinal juice will be altered by changes in viscosity that are induced, for instance, by meal components. An increased dissolution rate could be obtained at more intense intestinal motility patterns or increased... 

The stability of niclosamide was studied in simulated gastric and intestinal juices, with and without enzymes, after incubation at 37°C. The remaining intact drug and its degradation products (2-chloro-4-nitroaniline and 5-chlorosalicylic acid) were extracted with chloroform/methanol (5 1) and determined by TLC and HPLC. The drug was stable in these media for at least 6 h [68]. 

A stability-indicating HPLC method has been described for niclosamide in artificial gastric and intestinal juices [68],... 

Roily and Liebermeister [95] showed that bacteria introduced into the small bowel disappeared rapidly, without bile, pancreatic, and intestinal juices having antibacterial properties alone or mixed. Later studies, of which those by Dack and Petran [96], Dixon [99] and Dixon and Paulley [100] are of particular importance, provided considerable further evidence that intestinal peristalsis is the main line of defense against bacterial colonization of the small bowel. This was also concluded by Donaldson [101-103] when he reviewed host defense mechanisms in 1964. At that time, however, the insights into small bowel motility were confined to the reflex-mediated peristaltic behavior. 

In 1969 the Joint Study Group of the Indian Council of Medical Research—Government of West Bengal— WHO Cholera Research Project investigated the immunoglobulin levels in serum, intestinal juice, and feces from patients with cholera and noncholeraic diarrhea. They reported the following findings ... 

Can these be measured Tablet dissolution can be measured in a laboratory where a tablet is exposed at 37°C to a solution made up to resemble gastric or intestinal juice. This is the method the pharmaceutical... 

The intestinal juice is mostly water but also contains some mucus that is secreted by the duodenal glands and the goblet cells of the mucosa. Blood pH is usually in the range of 7.35-7.45 (Ignatavicius and Workman, 2002), whereas urine has a typical pH of 4.2 (Hansch and Leo, 1979). The body has many mechanisms that ensure minimal changes in pH. Many microbial processes are inhibited by acidic conditions. For a standard ionizing compound ... 

Yoshino, K., Suzuki, M., Sasaki, K., Miyase, T., and Sano, M., Eormation of antioxidants from (—)-epigallocatechin gallate in mild alkaline fluids, such as authentic intestinal juice and mouse plasma, J. Nutr. Biochem., 10, 223, 1999. 

The drugs which are destroyed by the gastric juices in the stomach, are coated with keratin, shellac and cellulose acid phosphate. These substances are not dissolved by the acid juice of the stomach, but are dissolved in the intestinal juice (alkaline) only, which is useful in ... 

Other sources of melibiase are the seeds of alfalfa,39 guar,40 coffee (unroasted),41 and pine42 barley malt36 cultures of Aspergillus oryzae36 and the intestinal juice of snails.37... 

RIVM Stomach Small intestine Oral cavity Gastric juice (pepsin, mucin), pH 2 Intestinal juice (porcine bile, trypsin, pancreatine), pH 7.5 Saliva, pH 6.5 Pb, Cr, Hg As, Cd, 5, 10... 

SHIME Stomach Small intestine Stomach Gastric juice (pepsin, mucin, BSA), pH 1.1 Intestinal juice (bovine bile, pancreatine, lipase, BSA), pH 8.0 SHIME medium (pectin, Pb As, Cd, 5, 13... 

The in vitro gastric and intestinal digests of selenized yeast food supplements were investigated by successive HPLC-ICP-MS and HPLC-ES-MS/MS [51]. The main compound extracted by both gastric and intestinal juice was Se-methionine, which was also the main Se compound extracted by proteolytic digestion from the yeast supplements. Two other minor compounds could be identibed as Se-cystine and Se(0)-methionine, a degradation product of Se-methionine [51]. 

The stomach also contains an enzyme, rennin, which assists in the digestion of milk, and another enzyme, lipase, which catalyzes the decomposition of fats into simpler substances. Additional enzymes involved in the digestion of polysaccharides, proteins, and fats take part in the continuation of the digestion in the intestines these enzymes are contained in the intestinal juice, pancreatic juice, and bile. 

The problem with the aforementioned monolithic unit system is that it tends to be detained at the ileocecal junction, leading to drug loss before entry in the colon. To circumvent this problem, multiparticulate dosage forms were devised that passed freely through the ileocecal junction. In a recent study, a multiparticulate system, which was based on amidated pectin, was tested. ° Coating of the amidated pectin beads with chitosan significantly reduced the release of sulfamethoxazole and indomethacin in simulated gastric and intestinal juice compared with non-coated beads. 

Acid insoluble film coat dissolves in intestinal juice... 

The hydrolysis of desoxyribosenucleic acid to the constituent nucleosides was achieved by Levene and London in 1929, by the action of the enzymes of intestinal juice. They passed a solution of the acid through a segment of the gastro-intestinal tract of a dog, and collected it from an intestinal fistula. The solution was then covered with a layer of toluene and incubated in a thermostat during four to seven days, small portions of gastro-intestinal secretion being added daily. The digestion mixture was now poured into twice its volume of 95% ethyl alcohol, filtered, and the nucleosides isolated from the filtrate. 

Inorganic nutrients lost in the urine represent nutrients that must be consumed in the diet to maintain nutrient balance. The metal ions that are secreted in gastric juices and intestinal juices are not necessarily lost from the body. They are efficiently reabsorbed by the intestinal tract. Vomiting, however, leads to loss of both gastric and intestinal juices. Diarrhea leads to loss of intestinal juices. 

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