Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Magnesium Hydroxide”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1984

Mechanism of freeze-thaw instability of aluminum hydroxycarbonate and magnesium hydroxide gels.

The effect of freeze-thaw cycles on the physical stability of aluminum hydroxycarbonate and magnesium hydroxide gels was studied. Coagulation following a freeze-thaw cycle, leading to the formation of visible aggregates, affected the content uniformity of both gels. The freeze-thaw cycles did not affect the crystal form or surface characteristics of the gels as determined by X-ray powder diffraction and point of zero charge, but caused a slight reduction in the rate of acid neutralization and a large increase in the rate of sedimentation. The greatest effect was observed after the first freeze-thaw cycle. While the duration of freezing was not a factor, the rate of freezing was important and was inversely related to the aggregate size. The aggregates which formed following a freeze-thaw cycle were not redispersed by shaking, but were reversed by ultrasonic treatment or homogenization. The adsorption of polymers or surface-active agents prior to freezing reduced and, in some cases, prevented the formation of aggregates. The physical instability produced by a freeze-thaw cycle was explained by the modified DLVO theory. The force exerted on the particles by the growing ice crystals forced the particles into the primary minimum, producing strong interparticle attraction. On thawing, simple agitation did not provide enough force to overcome the attractive force of the primary minimum. Adsorption of polymers or surface-active agents increased the steric repulsive force and prevented the particles from reaching the primary minimum.

Aluminum Hydroxide↗
PubMedDate not supplied

Effect of orally administered magnesium hydroxide in experimental iron intoxication.

We have previously shown that ferrous and ferric ions readily for complexes with magnesium hydroxide [Mg(OH)2] thus reducing the absorption of iron salts from the gastrointestinal tract. The present study answers the following question: what is the optimal dose, time of administration, optimal limit of effectiveness, and potential hazard of this form of therapy. Adult mongrel dogs were administered ferrous sulfate [FeSO4] tablets at a dosage of 650 mg/lb of body weight. Either 30 or 60 minutes later, the dogs were given Mg(OH)2 at either 5 or l0 times the dose of elemental iron. Serum iron concentrations in all animals given Mg(OH)2 were significantly lower (p less than 0.05) than those of control animals. No significant differences were observed regardless of dose or time of administration of Mg(OH)2. Although serum Mg++ concentrations were significantly elevated (p less than 0.05) om all treated animals 4 and 6 hr post iron, no clinical manifestations of hypermagnesemia were observed. These studies demonstrate the effectiveness of Mg(OH)2 in the management of experimental iron intoxication and warrant a controlled clinical trial in humans.

Administration, Oral↗
PubMed1991

[Magnesium hydroxide and aluminum hydroxide in the treatment of gastroesophageal reflux].

Fifteen children with gastro-esophageal reflux took part in a treatment trial with a regimen of magnesium hydroxide and aluminium hydroxide for 8 weeks period (700 mmol/1.73 mq/die). All children were evaluated clinically and underwent a 24-hour continuous esophageal pH-monitoring both at diagnosis and after 8 weeks of treatment. After therapy 12/15 children were cured and 3/15 improved. Moreover the total percentage of time during which pH was less than 4, the number of reflux episodes and the number of refluxes lasting than 5' recorded during 24-hour continuous esophageal pH-monitoring were significantly reduced after treatment. The Authors conclude that antacids in large quantities are effective in medical treatment of gastro-esophageal reflux.

Aluminum Hydroxide↗
PubMed1987

[Magnesium hydroxide treatment of hyperphosphatemia in chronic hemodialysis patients with an aluminum overload].

The control of hyperphosphatemia in dialysis patients is frequently achieved using aluminium hydroxide (A1(OH)3) and/or calcium carbonate (Ca CO3). However, this effect is counterbalanced by risk of aluminium intoxication and hypercalcemia. An alternative to the use of these phosphate binders is the prescription of magnesium hydroxide (Mg(OH)2) in association with a magnesium free dialysate. 19 patients with subtoxic plasma aluminium concentration received such a therapy. 9 months after starting the essay 4 patients had been excluded for digestive intolerance (3 cases) and neuro-psychic symptoms related to hypermagnesemia (1 case) after therapy with maximal doses of 6 to 12 g/d. Plasma inorganic phosphorus was decreased from 2.47 +/- 0.32 to 1.86 +/- 0.40 mmol/l (P less than 0.05) and plasma aluminium from 3.03 +/- 0.93 to 1.52 +/- 0.15 mumol/l (P less than 0.05). The results have been obtained without any significant increase in plasma and red cell magnesium levels. Metabolic alkalosis has been observed in association with the increase of ion exchange resin (sodium polystyrene sulfonate: Kayexalate) to treat progressive hyperkalemia. With the exception of possible metabolic effects occurring on a long term basis, Mg(OH)2 in association with magnesium-free dialysate seems of value to treat dialysis hyperphosphatemia.

Adult↗
PubMed1999

Effect of magnesium hydroxide administration on iron absorption after a supratherapeutic dose of ferrous sulfate in human volunteers: a randomized controlled trial.

STUDY OBJECTIVE: Animal models have demonstrated that administration of magnesium hydroxide (MgOH) decreases serum iron levels after an iron overdose. We designed this study to determine the effect of MgOH administration on iron absorption and adverse effects after a supratherapeutic dose of ferrous sulfate in healthy male volunteers. METHODS: We conducted a prospective, unblinded, randomized trial involving 16 healthy, fasting men. All subjects ingested a 10-mg/kg dose of elemental iron in the form of ferrous sulfate. One-half hour after the iron dose, the 8 subjects in the experimental group were given 5 mg of MgOH for every 1 mg of ingested elemental iron. Serum iron levels were obtained at baseline and at each subsequent hour for 6 or 7 hours. Serum magnesium levels were obtained at baseline, after 3 hours, and after 6 hours. Side effects were recorded hourly. Serum iron levels between groups were compared by repeated-measures ANOVA and ANCOVA. The 95% confidence intervals (CIs) for the difference in serum iron levels between groups at each time point and for the difference in peak serum iron level between groups were calculated. RESULTS: Baseline mean serum iron levels did not differ between the 2 groups (P =.28). There were no statistical differences between groups (P =.20). Mean serum iron levels at each time point and peak serum iron levels did not differ significantly between groups. The mean peak serum iron level was 300.8 micrograms/dL in the control group and 272.5 micrograms/dL in the experimental group. CONCLUSION: Administration of MgOH does not affect iron absorption in humans after a supratherapeutic dose of iron when the ratio of MgOH to elemental iron is 5:1.

Adult↗
PubMed1967

Pemoline and magnesium hydroxide: lack of effect on RNA and protein synthesis.

Brain RNA polymerase isolated from rats treated with pemoline and magnesium hydroxide (Cylert) was not more active than enzyme from control animals. The drug did not increase enzymic activity in vitro. Pemoline did not significantly affect either RNA or protein synthesis in suspensions of Ehrlich ascites carcinoma cells.

Animals↗
PubMed1989

Influence of ranitidine, pirenzepine, and aluminum magnesium hydroxide on the bioavailability of various antibiotics, including amoxicillin, cephalexin, doxycycline, and amoxicillin-clavulanic acid.

Two randomized double-blind crossover studies and one randomized crossover study were performed to document possible drug-drug interactions between antacids (aluminum magnesium hydroxide, 10 ml per dose for 10 doses), antimuscarinic drugs (pirenzepine, 50 mg per dose for 4 doses), and H2-blockers (ranitidine, 150 mg per dose for 3 doses) and amoxicillin (1,000 mg), cephalexin (1,000 mg), doxycycline (200 mg), and amoxicillin-clavulanic acid (625 mg). Ten healthy volunteers participated in each study. Concentrations in serum and urine were measured by bioassay, and pharmacokinetic parameters were calculated by the usual open one- or two-compartment models (statistics were determined by the Wilcoxon test). The antacid, pirenzepine, and ranitidine had no influence on the bioavailability of amoxicillin, cephalexin, and amoxicillin-clavulanic acid. Only small differences could be observed in the pharmacokinetic parameters, but they are not of therapeutic importance. However, the antacid caused a significant (P less than 0.01) reduction in the gastrointestinal absorption of doxycycline (area under the concentration-time curve, 38.6 +/- 22.7 mg.h/liter, fasting; 6.0 +/- 3.2 mg.h/liter, with antacid), resulting in subtherapeutic levels of doxycycline.

Adult↗
PubMed1982

Preformed magnesium hydroxide precipitate for second-step concentration of enteroviruses from drinking and surface waters.

A method is described for the second-step concentration of viruses from large volumes of drinking and surface waters. Seeded viruses present in the first eluate, performed with 50 mM glycine buffer, pH 11.5, were adsorbed on a preformed magnesium hydroxide precipitate. After low-speed centrifugation they were desorbed and adjusted to pH 7 with McIlvaine citrate-phosphate buffer. In these experimental conditions 90% of the viruses present in the 300-mL first eluate were reconcentrated in a final volume of 40 mL. The recovery efficiency was independent of either virus concentration or water quality.

Chemical Precipitation↗
PubMed1991

Magnesium intoxication in a neonate from oral magnesium hydroxide laxative.

This is a case of magnesium intoxication in a neonate produced by an oral magnesium cathartic. A review of the literature revealed there are very few cases that have been reported of magnesium toxicity due to cathartics. There is no recommended dose for magnesium cathartics in neonates or data on their safety. A review of the management of magnesium intoxication is presented.

Administration, Oral↗
PubMed2006

A multielement masking method using magnesium hydroxide coprecipitation for the selective determination of lead in water samples by differential pulse anodic stripping voltammetry.

We present a new multielement masking method using magnesium hydroxide coprecipitation for the selective determination of Pb by differential pulse anodic stripping voltammetry (DPASV). The recovery of Pb in the masking method was over 95%, while interfering ions (Cd(2+), Co(2+), Cu(2+), Fe(3+), Mn(2+), and Ni(2+)) could be removed at 100% from the analytical sample. A linear regression was obtained in the Pb concentration from 10 to 1000 microg kg(-1) in the existence of 100 microg kg(-1) of the interfering ions. When this method was applied to the determination of Pb in a natural water-standard reference material (NIST 1640), the determined value for Pb in this work (25.4 +/- 4.1 microg kg(-1)) almost agreed with the certified value (27.89 +/- 0.14 microg kg(-1)).

Journal Article↗
PubMed2004

Determination of a polymeric hindered amine light stabilizer in polypropylene formulated with magnesium hydroxide flame retardant by reactive thermal desorption-gas chromatography.

A polymeric hindered amine light stabilizer (HALS), Tinuvin 622 (MW [symbol: see text] 4000), in PP materials formulated with a magnesium hydroxide flame retardant was determined by reactive thermal desorption (RTD) gas chromatography (GC). Two kinds of the HALS components that were formed through the RTD in the presence of tetramethylammonium hydroxide [(CH3)4NOH, TMAH] were clearly observed in the chromatograms of the PP samples, with negligible interference from the other additives and the PP substrate. Here, the coexisting flame retardant was proved to affect significantly the RTD process of the occluded HALS. As a result, the recovery of the HALS components in the RTD-GC chromatograms of the PP samples increased with increase in the content of the flame retardant. This enhancement of the HALS recovery is attributed mainly to the preferential exposure of the HALS on the surface of the ground PP sample through the interaction between the polymeric HALS and the flame retardant in the molten PP during kneading. In spite of such a considerable action of the flame retardant, the observed intensities of the characteristic peaks of HALS by RTD-GC showed a good linear relationship with the HALS content in the PP samples with constant content of the flame retardant (50 phr); this relationship could be used as the calibration line for the determination of the polymeric HALS in the PP materials containing the flame retardant.

Journal Article↗
PubMed1990

Bioavailability of magnesium in beef cattle fed magnesium oxide or magnesium hydroxide.

Two experiments were conducted to compare Mg bioavailability from Mg oxide (MgO) vs Mg hydroxide (Mg(OH)2) fed in either a completely mixed diet or a mineral supplement. In Exp. 1, these Mg sources were incorporated into completely mixed diets and offered to 15 steers (282 kg) allotted to three treatments: control diet containing .19% Mg, control plus .2% added Mg as MgO, or control plus .2% added Mg as Mg(OH)2. Each calf was fed 5 kg/d of the respective diet during 10-d adjustment and 7-d collection periods. Blood samples were collected on d 1, 3 and 7. Mg supplementation increased (P less than .01) fecal and urinary Mg excretions, whereas apparent Mg absorption (%) and retention were similar (P greater than .10) for all treatments. Plasma Mg concentrations were similar (P less than .10) for calves supplemented with MgO and Mg(OH)2 but were higher (P less than .05) for Mg supplemented than for control calves on d 7. In Exp. 2, these Mg sources were incorporated into mineral supplements and offered free choice to 30 spring-calving beef cows gazing tetany-inducing pastures from March 6 to May 1. Each of three groups of 10 cows was assigned to a 5.7-ha tall fescue pasture and offered either a control supplement or a supplement containing 40% MgO or Mg(OH)2. Blood samplers were collected on d 0, 7, 14, 28, 42 and 56. Plasma Mg concentrations were not different (P greater than .10) for cows offered MgO and Mg(OH)2 but were higher (P less than .01) for Mg-supplemented than for control cows on d 28, 42 and 56.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1992

Influence of dielectric constant on sedimentation rate of concentrated suspensions of aluminum and magnesium hydroxides.

Sedimentation of dilute pharmaceutical suspensions obeys Stokes's law, which assumes that there is no interaction between particles. The behavior of concentrated pharmaceutical suspensions is generally interpreted by use of modifications of Stokes's law that do not consider chemical interaction between particles. Properties of the medium itself, such as dielectric constant and surface tension, have not been included in the established equations. The present work shows that the dielectric constant of the medium has a distinct effect on the rate of sedimentation of the systems investigated.

Aluminum Hydroxide↗