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PubMed1984

[Digitoxin blood picture and renal elimination in long-term therapy with aluminum-magnesium hydroxide gel].

In ten patients in heart failure for which they were on long-term administration of digitoxin, the influence of aluminium-magnesium hydroxide gel (Maaloxan) on steady-state digitoxin plasma concentration and renal glycoside excretion was studied. Compared with control values before antacid medication (13.6 +/- 4.4 ng/ml), the administration of 20 ml aluminium-magnesium hydroxide gel three or four times daily for several weeks caused no significant change in digitoxin plasma levels (15.1 +/- 4.9 ng/ml). Daily renal glycoside excretion, as a further measure of bioavailability of digitoxin, was also unchanged by the antacid. Therapeutic plasma concentrations of digitoxin are not influenced by antacids which contain aluminium-magnesium hydroxide, at least not if the antacid is taken 1-2 hours after the digitoxin dose.

Aged↗
PubMed2007

An in vitro study of the pH of three calcium hydroxide dressing materials.

Calcium hydroxide is widely used as a root canal dressing material because of its favorable alkalinizing effect. It has been suggested that the action comes from diffusion of hydroxyl ions through the apical foramen. The purpose of this in vitro study was to test the pH changes that occurred over a period of 30 days using a mixture of calcium hydroxide and distilled water and two commercial calcium hydroxide products in a simulated periapical environment. The materials were inserted in glass tubes closed at one end, which were placed in individual vials containing distilled water at a pH 7.4. Unfilled glass tubes were used as controls. Alkalinity changes of the medium were measured at 1 and 24 h and 15 and 30 days. The alkalinizing properties of all materials showed a rapid increase at 1 and 24 h followed by a continuous but more gradual increase from 15 to 30 days. The control tubes did not cause a change in pH of the medium, which remained at pH 7.4. At the end of the observation period, the alkalinizing properties of Calasept and Ultracal XS were significantly higher (P < 0.05) than the calcium hydroxide/distilled water paste.

Analysis of Variance↗
PubMed1977

A comparison of an antacid plus antispasmodic combination and aluminium hydroxide in dyspepsia.

A single-blind, between-patient comparative study was carried out in general practice to assess the effectiveness of antacid plus antispasmodic combination tablets (240 mg dried aluminium hydroxide B.P., 144 mg magnesium hydroxide B.P.C., and 5 mg dicyclomine hydrochloride B.P.) and aluminium hydroxide B.P. tablets (500 mg) in the management of chronic dyspepsia. Twenty patients received the combination tablets and 17 the single antacid tablets. They were instructed to chew 2 tablets 3 or 4-times daily and an additional 2 tablets at night if necessary. Patients were assessed initially, and then at 2 and 4 weeks. Both preparations were effective in controlling dyspeptic symptoms. Heartburn and nausea showed an early, significantly greater (p less than 0.05) response to the combined tablet, as did night pain after 4 weeks. Tablet intake of both preparations averaged out at just under 7 tablets per day.

Aluminum Hydroxide↗
PubMed1990

[The effect of aldioxa on the formation of gastritis induced with sodium hydroxide].

The effects of aldioxa and cetraxate hydrochloride on the formative process of gastritis induced with intragastric application of 2% sodium hydroxide were studied. Rats were given food including either aldioxa or cetraxate hydrochloride for 6 weeks after the sodium hydroxide application. After sacrifice, the stomachs were removed, and the gastric mucosa were observed macroscopically and histologically. Gastric mucosal injury was widely induced with sodium hydroxide, being histologically characterized by mucosal hypertrophy, cell infiltration and intestinal metaplasia. These lesions seem to be the early stage of chronic gastritis. The aldioxa group showed a decrease of mucosal hypertrophy and cell infiltration as compared with the control group. In the cetraxate hydrochloride group, the mucosal surface of white gray color and the mucosal bosselation were observed macroscopically. Histologically, these were found to be cell infiltration and cyst formation. Moreover, intestinal metaplasia occurred at high incidence in this group. These findings in the cetraxate hydrochloride group are recognized to be an aggravation of chronic gastritis. From the above results, it is suggested that aldioxa promotes good regeneration of mucosa and should be useful for the clinical therapy of chronic gastritis.

Allantoin↗
PubMed2004

Lack of effect of omeprazole or of an aluminium hydroxide/magnesium hydroxide antacid on the pharmacokinetics of lumiracoxib.

OBJECTIVE: To evaluate the effects of multiple doses of omeprazole and of a single dose of an aluminium hydroxide/magnesium hydroxide (Al/Mg) antacid on the single-dose plasma pharmacokinetics of lumiracoxib. STUDY DESIGN: Open-label, randomised, three-period, crossover study. POPULATION STUDIED: Healthy subjects aged 18-65 years. METHODS: Fourteen subjects who met eligibility criteria were each administered three treatments in random order: (A) lumiracoxib 400 mg as a single oral dose; (B) oral omeprazole 20 mg once daily for 4 consecutive days, then lumiracoxib 400 mg as a single oral dose just prior to oral omeprazole 20 mg on day 5; and (C) lumiracoxib 400 mg as a single oral dose immediately prior to a 20 mL dose of Al/Mg antacid (magnesium hydroxide 800 mg and aluminium hydroxide 900 mg). The interval between each lumiracoxib dose was 7 days. Analysis of variance was performed to determine whether lumiracoxib alone differed from lumiracoxib plus omeprazole or from lumiracoxib plus Al/Mg antacid for overall exposure (area under the concentration-time curve from zero to infinity [AUC( infinity )]) and peak concentration (C(max)), with treatment sequence, subject, period and treatment as factors. Ratios of geometric means between lumiracoxib plus omeprazole and lumiracoxib plus Al/Mg antacid to lumiracoxib alone (reference) were calculated for AUC( infinity ) and C(max). If the mean ratios, with 90% CIs, fell within the interval 0.80-1.25, the treatments were considered equivalent. RESULTS: Arithmetic mean plasma lumiracoxib concentration-time profiles were similar for all treatments, with a rapid rise in concentration after administration, reaching C(max) values (mean +/- SD) of 9.24 +/- 1.96, 8.81 +/- 2.30, and 10.43 +/- 3.24 mg/L within 2-3 hours for treatments A, B and C, respectively. AUC( infinity ) was similar for the three treatments (36.75 +/- 7.73, 34.88 +/- 8.40 and 35.50 +/- 5.72 mg. h/L). All ratios of geometric means with 90% CIs fell within the interval used for establishing bioequivalence, except for the C(max) comparison between lumiracoxib plus Al/Mg antacid and lumiracoxib alone, which was 1.11 (0.95, 1.31). CONCLUSIONS: Coadministration of lumiracoxib with omeprazole or with an Al/Mg antacid had no clinically significant effect on lumiracoxib single-dose plasma pharmacokinetics. Lumiracoxib can, therefore, be administered concurrently with either of these agents without need for lumiracoxib dosage alteration.

Adolescent↗
PubMed1984

Comparison of the antacid properties of almagate and aluminium hydroxide against pentagastrin-induced gastric secretion in healthy volunteers.

The potency of a new antacid, almagate (hydrated aluminium-magnesium hydroxycarbonate, Al2Mg6 (OH)14(CO3)2 X 4 H2O, Almax) has been compared with that of aluminium hydroxide in neutralizing pentagastrin-induced hyperacidity in healthy human volunteers. Almagate (1 g) produced a significantly (p less than 0.01) greater reduction (87.5%) in the titratable acid content of gastric aspirates than did an identical dose of aluminium hydroxide (45.1%). Similarly the pepsin proteolytic activity in the samples of gastric juice was reduced 58.9% by almagate and only 27.5% by aluminium hydroxide. Furthermore the neutralizing effect of almagate was more prolonged (90 min) than that of the standard antacid (30 min) and these first studies in man have therefore confirmed the findings of in vitro and in vivo preclinical experiments.

Adult↗
PubMed1993

Improved tissue corrosion of vascular casts: a quantitative filtration method used to compare tissue corrosion in various concentrations of sodium and potassium hydroxide.

In this study, we compare weights of filter retained material (11 microns particle retention) after solubilization and filtration of unfixed, un-perfused tissue (fat, liver and trachea) in sodium and potassium hydroxide (1%, 5%, 10% and 20% weight/volume, w/v) at 8, 24 and 48 hour time points at 45 degrees C. Three detergents [1% Triton-X-100 (volume/volume, v/v), 1% 7X (v/v), 1% Terg-A-Zyme (w/v)] used in combination with hydroxide were evaluated for use in solubilizing fat. Additionally, vascular casts from mouse kidneys were corroded to test the practical effectiveness of corroding solutions on resin infused tissue. Five percent KOH for eight hours proved to be the most effective concentration and time required to corrode fatty tissue. Liver tissue was corroded most rapidly in 1% to 5% NaOH or in 1% to 20% KOH. Corrosion of trachea tissue showed that 5, 10 and 20% hydroxide (NaOH or KOH) are equally effective after 8 hours of corrosion. Use of detergents improved solubilization of fat when combined with 2%, 3% or 5% NaOH. However, fatty tissue was solubilized more rapidly without the use of detergents in 1% NaOH. Scanning electron microscopy of vascular casts shows that corrosion in 1% NaOH appears equally as effective as corrosion in 15% KOH.

Adipose Tissue↗
PubMed2005

System zones in capillary zone electrophoresis: moving boundaries caused by freely migrating hydroxide ions.

We present theoretical and experimental data indicating that anionic system zones (SZs), due to free migrating hydroxide anions, can be expected in background electrolytes (BGEs) with a low buffer capacity. In the system containing completely unbuffered BGEs the hydroxide ions derived from the sample start to migrate freely through the capillary tube with the mobility of single hydroxide ions and cause stepwise disturbances in the baseline of the detector trace. Remarkably, this type of SZs do not appear to contribute significantly to the electromigration dispersion (EMD) of the zones of the analytes.

Buffers↗
PubMed1976

Structure of aluminum hydroxide gel II: aging mechanism.

The aging of aluminum hydroxide gel prepared by the reaction of aluminum chloride and ammonium hydroxide was studied by measurement of pH, acid-consuming capacity, hydroxide to aluminum ratio, chloride activity, and X-ray line broadening. The results were consistent with a polymer model involving particle growth by a deprotonation-dehydration mechanism. Anions inhibit this reaction by binding to the positively charged edges of the hydroxyaluminum polymers.

Aluminum Hydroxide↗
PubMed1976

Structure of aluminum hydroxide gel III: mechanism of stabilization by sorbitol.

The effect of sorbitol on the aging of aluminum hydroxide gel, prepared by the reaction of aluminum chloride solution with strong ammonia solution to a final pH of 7.0, was studied by potentiometric titration, acid-consuming capacity, pH, hydroxide to aluminum ratio, chloride activity, X-ray diffraction, and IR spectroscopy. Gels containing sorbitol lost less than 10% of their acid-consuming capacity during a 6-month aging period compared with a loss of more than 60% for an identical gel without sorbitol. The mechanism by which sorbitol stabilizes the gel appears to be inhibition of the secondary polymerization reaction which takes place upon aging. Another polyhydroxy compound, quercetin, also stabilizes aluminum hydroxide gel.

Aluminum Hydroxide↗
PubMed1976

Differential thermal analysis of aluminum hydroxide gel.

The development of order during the aging of aluminum hydroxide gel prepared by the reaction of aluminum chloride and ammonium hydroxide to a final pH of 7.0 can be monitored by differential thermal analysis. The loss of acid reactivity upon aging is accompanied by an increase in the temperature and intensity of the dehydroxylation endotherm and an accompanying decrease in the intensity of the water of hydration endotherm. With continued aging, the thermogram develops the characteristics of a crystalline aluminum hydroxide.

Aluminum Hydroxide↗
PubMed1981

Aluminum chlorohydrate III: Conversion to aluminum hydroxide.

Bayerite, an aluminum hydroxide polymorph, readily forms when the hydroxyl to aluminum ratio of aluminum chlorohydrate is raised to 3 by titration with sodium hydroxide. Dilution of aluminum chlorhydrate solutions with water leads to the formation of gibbsite, another aluminum hydroxide polymorph. The mechanism of conversion in each instance is related to the structure of the Al13O4(OH)24(H2O)7+(12) complex.

Aluminum Hydroxide↗
PubMed1981

Effective therapy of enteric hyperoxaluria: in vitro binding of oxalate by anion-exchange resins and aluminum hydroxide.

Hyperabsorption of dietary oxalate is a major factor in the pathogenesis of enteric hyperoxaluria and a frequent complication of inflammatory bowel disease and ileojejunal bypass surgery. Successful treatment requires reduction in oxalate intake or inhibition of absorption of dietary oxalate by oral ingestion of oxalate binding agents. To identify such agents, oxalate binding by anion-exchange resins, gums, and aluminum hydroxide was measured under conditions that simulated those present in the intestinal lumen. Of the agents tested, those that bound oxalate best were colestipol and aluminum hydroxide. Strongly basic anion-exchange resins readily bound oxalate only in the absence of chloride. These results suggest that colestipol and aluminum hydroxide administration might reduce dietary oxalate absorption in patients with enteric hyperoxaluria.

Adsorption↗
PubMed1981

Mechanism of interaction between polyols and aluminum hydroxide gel.

IR spectroscopy and changes in the rate of acid neutralization were used to study the interaction between various polyols and aluminum hydroxide. Hydrogen bonding is responsible for this interaction, although structural requirements limit the polyols that interact with aluminum hydroxide. Mannitol and sorbitol, both linear polyols, interacted with sulfate-containing aluminum hydroxide gel and aluminum hydroxycarbonate gel, while inositol, a cyclic polyol, did not interact. The adsorbed polyol has the favorable effect of inhibiting the polymerization reaction that occurs on aging and the negative effect of reducing the rate of acid neutralization. Thus, the specific polyol and concentration must be carefully selected to maximize the desired effect of stabilizing the gel structure. The presence of mannitol in the reaction medium during precipitation did not significantly enhance gel structure stability, probably because the mannitol was desorbed during the washing process as a consequence of the weak adsorption forces.

Adsorption↗
PubMed1986

Preparation, characterization, and controlled release from coprecipitates of fluorescein and magnesium hydroxide.

Magnesium hydroxide was precipitated as a lyophobic sol in the presence of various concentrations of fluorescein sodium (3'6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthen++ +]-3-one, disodium salt) ranging in molar equivalents between 0.1 and 2 times that of the hydroxide. Coprecipitates were washed and dried, and release of the dye and magnesium was determined (pH 7.4, 37 degrees C) from rotating disks. Release rates varied depending upon fluorescein content. The rate of dye release was retarded by less than or equal to 10(4) times that of fluorescein sodium alone, implying the existence of some form of solid association between the components of the coprecipitates. The presence of the dye in certain concentrations reduced magnesium hydroxide dissolution rates by a factor of three. Fluorescein dissolution rates, when expressed as percent release, passed through a minimum (coincident with the dye-induced reduction in Mg(OH)2 dissolution). Adsorption experiments revealed evidence for multiaffinity binding of fluorescein at the surface of freshly precipitated Mg(OH)2. Magnesium, fluorescein, and water contents of the coprecipitates were characterized by atomic absorption and UV spectroscopy and by thermogravimetric analysis. Fluorescein content increased in direct proportion to its initial concentration in solution. Controlled, but variable release of this easily assayed dye is possible by employing precipitates with different fluorescein contents.

Adsorption↗
PubMed2002

Textural and chemical characterizations of adsorbent prepared from palm shell by potassium hydroxide impregnation at different stages.

Preparation and characterization of activated carbon from palm shell, a carbonaceous agricultural solid waste, by potassium hydroxide treatment at different stages were studied. The effects of activation temperature and chemical to sample ratio on the characteristics of the activated carbon were investigated. Fixed-bed adsorption of sulfur dioxide (SO(2)) gas was carried out to evaluate the adsorptive capacity of the samples. Desorption tests were conducted to verify the occurrence of chemisorption due to some surface functional groups or of chemical reaction between SO(2) and KOH. It was found that pre-impregnation of raw palm shell was involved in replacement of some hydrogen ions with potassium ions to form cross-linked complexes, which retarded the tar formation during carbonization, resulting in a relatively high yield. Moreover, these potassium ions accelerated the reaction as catalysts during gasification of chars by carbon dioxide. For chars with mid-impregnation, potassium hydroxide acted in two ways: (i) formation of metallic potassium by dehydration and (ii) conversion into potassium carbonate. Metallic potassium intercalated to the carbon matrix accounted for pore development and potassium carbonate layer prevented the sample from over burn-off. Post-impregnation of final products modified the textural characteristics of the sample as some pore entrances were blocked by chemicals. However, potassium hydroxide enhanced the amount of SO(2) uptaken via formation of potassium sulfite.

Adsorption↗
PubMed1991

Calcium carbonate as a phosphate binder in dialysis patients: evaluation of an enteric-coated preparation and effect of additional aluminium hydroxide on hyperaluminaemia.

Calcium carbonate has been successfully used as a phosphate binder in patients with chronic renal failure; however, a high frequency of hypercalcaemia has been reported. To study the effects of calcium carbonate preparations with different dissolution characteristics on the incidence of this side effect, we conducted a double-blind, crossover trial in 21 patients undergoing chronic haemodialysis. Aluminum hydroxide therapy was replaced with calcium carbonate. The subjects then randomly received either an enteric-coated or a gastric-coated preparation. Calcium carbonate (3.1-3.6 g/d) controlled serum phosphate concentrations as effectively as aluminium hydroxide (2.9 g/d). Concurrently, there was a significant rise in mean serum calcium and a fall in serum concentrations of both parathyroid hormone and osteocalcin, the latter suggesting a decrease in bone turnover. Overall, hypercalcaemic episodes developed in 9 patients (43%) and occurred at a considerable frequency (33 episodes per 100 patient-months) during treatment with the gastric-coated formulation. Following conversion to enteric-coated calcium carbonate (3.6 g/d) patients had fewer occurrences of hypercalcaemia (12 episodes per 100 patient-months, P less than 0.05) and, as compared to the gastric-coated preparation, increases in serum calcium greater than 3.00 mmol/l were not observed at all. Hyperaluminaemia was regressive during therapy with calcium carbonate, but addition of small doses of aluminium hydroxide caused a large rise in serum aluminium concentrations after infusion of desferrioxamine, indicating an enhanced rate of absorption or aberrant compartmentalization of aluminium. We conclude that calcium carbonate can control hyperphosphataemia in dialysis patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum↗
PubMed1981

Separation of wax esters from steryl esters by chromatography on magnesium hydroxide.

Chromatography of stearyl oleate and cholesteryl oleate on thin layer plates coated with magnesium hydroxide-celite, 1:1, or magnesia-celite, 1:1, showed that magnesium hydroxide had better resolving power for the separation of these wax ester and steryl ester model compounds than did magnesia, an adsorbent which has been used previously for this separation. By means of high pressure liquid chromatography on magnesium hydroxide, wax esters and steryl esters from the skin surface lipids of human, rat and monkey were separated completely and without hydrolysis.

Animals↗