Alkaline fluids

The pancreas is a gland in the abdomen lying in the curvature of the stomach as it empties into the duodenum. The pancreas functions primarily as an exocrine gland, although it also has endocrine function. The exocrine cells of the pancreas are called acinar cells. They produce an alkaline fluid known as pancreatic... 

A complication here, however, is noted with those drugs that exhibit a limited chemical stability in either acidic or alkaline fluids. Since the rate and extent of degradation is directly dependent on the concentration of drug in solution, an attempt is often made to retard dissolution in the fluid where degradation is seen. There are preparations of various salts or esters of drugs (e.g., erythromycin) that do not dissolve in gastric fluid and thus are not degraded there but which dissolve in intestinal fluid prior to absorption. A wide variety of chemical derivatives are used for such purposes. 

According to Knauss and Wolery (1988), this rate law is valid for neutral to acidic solutions a distinct rate law applies in alkaline fluids, reflecting the dominance of a second reaction mechanism under conditions of high pH. 

The fluid contains arbitrarily small amounts of Ca++, Mg++, and HCO3, as is necessary in order for the program to be able to recognize dolomite. The initial magnesium content is set small to assure that the hydroxide mineral brucite is not supersaturated in the alkaline fluid. 

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. 

Zhang, Y., Thomas, B. S., Lumpkin, G. R., Blackford, M., Zhang, Z., Colella, M. Aly, Z. 2003. Dissolution of synthetic brannerite in acidic and alkaline fluids. Journal of Nuclear-Materials, 321, 1-7. 

BILE. A biller alkaline fluid secreted by the liver inLo llie duodenum, which aids in the digestion of food. The chief components of bile are bile salts and bile pigments. Because of its strong alkalinity, bile neutralizes the acid coming into the duodenum from the stomach. The bile not only performs important functions in the process of digestion, but also serves as a vehicle for the excretion of waste products from the body. 

Together, CCK and secretin cause contraction of the gall bladder and the exocrine secretion of a bicarbonate-rich, alkaline fluid, containing protease proenzymes from die pancreas into the intestine. 

Pancreatic juice contains an alkaline fluid and enzymes, both of which empty into the duodenum. The alkaline pH contributes to neutralization of the acid that empties from the stomach. The enzymes amylase, lipase, trypsin, and chymotrypsin play major roles in the digestion of carbohydrates, fats, and proteins. Trypsin and chymotrypsin are secreted as inactive precursors and are converted to the active forms enzymatically. 

The time for a medication to disintegrate and dissolve is called the rate limiting time. Table 2.1 shows the rate-limiting time for medication forms. Rate limiting time is higher if the medication is in acidic fluids rather than alkaline fluids. 

Fig. 1 pH scale showing values for familiar commodities (above the scale) and various environmental fluids discussed in this book (below the scale). Soil pH is measured on pure water (pH 7) equilibrated with the soil solids. Note that naturally alkaline fluids are rare. Industrial processing that involves strong bases like NaOH (e.g. bauxite processing) or Ca(OH)2 (lime production) can contaminate river waters to around pH 10. 

According to Davis and Ashenberg (1989), the results of the simulations provide some useful information for the evaluation of the feasibility of using alkaline tailings fluid to neutralize Berkeley Pit water as a remedial action. The authors calculated that it needs three volumes of alkaline fluids to neutralize the pit lake water to pH of 5.0 with the Case 3 scenario. That would result in a water level 20 m above the contact between the alluvial aquifer and the subjacent bedrock, assuming all inflows into the pit except alluvial and bedrock groundwater contributions can be controlled. The authors concluded that this remedial alternative is a tractable solution to the acid mine drainage problems at the Berkeley Pit. 

Sepiolite precipitates from the silica-rich alkaline fluid according to the reaction ... 

Take of alkaline fluid extract of rhubarb, 3 fluid ounces. See 4591.) Xeutral carbonate of potassa, 240 grains cinnamon water, 4 troy ounces dissolve Uio carbonate in the cinnamon water add the fluid extract, and then sufficient water to make the wbolo weigh... 

Alkaline Fluid Extract of Rhubajrb. Take of fluid extract of rhubarb (by repcrcoiation), I fluid ounce neutral carbonate of potassa, 80 grains water, 1 fluid ouneo. Dissolve the cart mate iu the water to this wid the fluid extract, and let the mixture repose C to 12 horirs then strain through muslin, and filter, if desirable. The alkaline fluid extract of rhubarb caii bo mixed with water in any proportion, affording a perfectly clear and transparent liquid of a deep red color. Another alkaline fluid extract of rhubarb will be found in No. 4386,... 

Alkaline Syrup Khubarb. Take of alkaline fluid extract of rhubarb, 6 fluid ounces see JVb. 4591) oil of cinnamon,... 

Reddish, odorless, tasteless, bulky powder, mp about 230 with decompn. Practically insol in water sot in alcohol, alkaline fluids. 

In 1954 Leusen (20) demonstrated that the perfusion of the brain ventricular system with an acid fluid stimulated ventilation while perfusion with an alkaline fluid depressed ventilation. These ventilatory responses were assumed to be caused by direct stimulation or depression of chemosensitive elements within the respiratory center. Loeshcke and co-workers (21, 22) were the first to present evidence that respiratory H+ chemosensitivity might be located outside the medullary respiratory... 

Analysis.—In fatal cases of poisoning by oxalic acid the contents of the stomach are sometimes strongly acid in reaction more usually, owing to the administration of antidotes, neutral, or even alkaline. In a systematic analysis the poison is to be sought for in the residue of the portion examined for prussic acid And phosphorus or, if the examination for those substances be omitted, in the residue or final alkaline fluid of the process for alkaloids. If oxalic acid alone is to be sought for, the contents of the stomach, or other substances if acid, are extracted with water, the liquid filtered, the filtrate evaporated, the residue extracted with alcohol, the alcoholic fluid evaporated, the residue redissolved in water (solution No. 1). The portion undissolved by alcohol is extracted with alcohol acidulated wdth hydrochloric. acid, the solution evaporated after filtration, the residue dissolved in water (solution No. 2). Solution No. 1 contains any oxalic acid which may have existed free in the substances examined No. 2 that which existed in the form of soluble oxalates. If lime or magnesia have been administered as an antidote, the substances must be boiled for an hour or two with potassium carbonate (not the hydroxid), filtered, and the filtrate treated as above. In the solutions so obtained, oxalic acid is characterized by the tests given above. The urine is also to be examined microscopically for crystals of calicum oxalate. The stomach may contain small quantities of oxalates as normal constituents of certain foods. 

A pair of pea-sized glands that lie beneath the prostate gland. Cowper s glands secrete an alkaline fluid that forms part of the semen. This fluid neutralizes the acidic environment of the urethra, thereby protecting the sperm. The glands are named after William Cowper (1666-1709). See also seminal vesicle. 

The addition of salt, or a solution thereof, to a concentrated alkaline solution of soap in water, precipitates the soim in gelatinous flocculss, and the mixture behaves precisely like solid soap boiled with a ddute solution of salt. Owbonated and caustic potassa act exactly like salt, by separating soap from tbe alkaline fluid (ley) in which it is absolutely insoluble. ... 

Prostate Organ that secretes an alkaline fluid as a component of semen. 

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