Aluminium hydroxide gel

Procedure. Prepare the sodium tetraphenylborate solution by dissolving 6.0 g of the solid in about 200 mL of distilled water in a glass-stoppered bottle. Add about 1 g of moist aluminium hydroxide gel, and shake well at five-minute intervals for about 20 minutes. Filter through a Whatman No. 40 filter paper, pouring the first runnings back through the filter if necessary, to ensure a clear filtrate. Add 15 mL of 0.1M sodium hydroxide to the solution to give a pH of about 9, then make up to 1 L and store the solution in a polythene bottle. 

Aluminium Hydroxide Gel Dissolve 0.5 g in 5 ml dil. HN03, boil, cool, dilute to 100 ml with DW and filter 2.5 ml used for the test. Complies with limit test for chlorides. 

Aluminium hydroxide can cause constipation, or even intestinal obstruction. Severe bowel dysfunction developed in 25 of 945 patients receiving long-term hemodialysis during 10 years (47). There was colonic perforation in 12 patients, six of whom died with peritonitis. In 10 other patients there was prolonged, severe, adynamic ileus that progressed to colonic pseudo-obstruction in eight. All had regularly taken aluminium hydroxide gel and had had chronic constipation before presentation. 

Antacids, particularly aluminium hydroxide gel, magnesium trisilicate, and sodium bicarbonate, reduce the systemic availability of rifampicin (97). 

The Cmax and AUC of tosufloxacin tosilate 300 mg were significantly reduced by aluminium hydroxide gel fine granules 1 g or magnesium oxide 1 g (2). 

Figure 6.20 Adsorption of digoxin by some antacids at 37 0.1°C ( ) magnesium trisilicate, (A) aluminium hydroxide gel BP (Aludrox was used in the concentration range 2.5-10%v/v), (A) light magnesium oxide, (O) light magnesium carbonate, ( ) calcium carbonate. Initial concentration of the glycoside 0.25 mg%.

Figure 10.16 Adsorption of digoxin from Lanoxin paediatric elixir at 37 0.1 °C by , Aluminium Hydroxide Gel BP (10% v/v) A, Magnesium Trisilicate Mixture BPC (10% v/v) A, Gelusil suspension (10% v/v) , Lanoxin elixir diluted 1 10 with water.

It may be necessary to exclude certain undesirable contaminants from starting materials, such as pseudomonads from bulk aluminium hydroxide gel, or to include some form of pre-treatment to reduce their bioburdens by irradiation, such as for ispaghula husk and spices. For biotechnology-derived drugs produced in human or animal tissue culture, considerable efforts are made to exclude cell lines contaminated with latent host viruses. Official guidelines to limit the risk of prion contamination in medicines require bovine-derived ingredients to be obtained from sources where bovine spongiform encephalopathy (BSE) is not endemic. 

Clinically important, potentially hazardous interactions with aluminium hydroxide gel, calcium containing preparations, iron preparations, magnesium preparations, NSAIDs... 

Sample Preparation Aluminium hydroxide gel was prepared by mixing equivalent amounts of non-ferric aluminium sulphate solution with a bicarbonate solution at 60 C. The gelatinous precipitate was kept 72h for ageing. The filtered precipitate was washed until free from anions. The filtered cake was oven dried at 120 C for 24h. The dried cake was pulverised and then kneaded with 1.0% nitric acid and extruded to desired size. The extrudates were calcined at 550 C for 12h. 

Examples of colloids include tea, starch and milk in water, gelatine (a protein) in water, aluminium hydroxide gel , and soapy water. Colloids are sometimes called colloidal solutions, colloidal suspensions or colloidal dispersions. 

A patient on quinidine who took eight Afy/ow/a tablets daily (aluminium hydroxide gel 200 mg, magnesium hydroxide 200 mg and simeticone 20 mg) for a week and a little over 1 litre of fruit juice (orange and grapefruit) each day developed a threefold increase in serum quinidine levels (from 8 to 25 mg/L) and toxicity. However, note that the grapefruit juice , (p.280) may have contributed. In 6 healthy subjects, this dose oiMylanta for 3 days produced consistently alkaline urine in 4 subjects, and in 5 subjects when combined with fruit juice. ... 

Romankiewicz JA, Reidenberg M, Drayer D, Franklin JE. The noninterference of aluminium hydroxide gel with quinidine sulfate absorption an approach to control quinidine-induced diarrhea. Am Heart J( 97S) 96, 518-20. 

Mauro VF, Mauro LS, Fr er TD, Temesy-Armos PN, Som P. Effect of aluminium hydroxide gel on quinidine gluconate absorption. Ann Pharmacother (1990) 24, 252-4. 

A study in 13 patients with tuberculosis, given a single 50-mg/kg dose of ethambutol, found that when they were also given three 1.5-g doses of aluminium hydroxide gel (at the same time and 15 and 30 minutes later) their peak serum ethamhutol levels were delayed and reduced. The average uri nary excretion of ethamhutol over a 10-hour period was reduced hy about 15%, but there were marked variations between individual patients. Some showed no interaction, and others showed increased absorption. No interaction was seen in 6 healthy subjects similarly treated. A further study in 14 healthy subjects found that 30 mL of an aluminium/magnesi-um hydroxide antacid decreased the AUC and maximum serum levels of a 25-mg/kg dose of ethambutol by 10% and 29%, respectively. ... 

A crossover study in 6 healthy subjects confirmed that aluminium hydroxide gel does not affect the absorption of nitrofurantoin from the gut (as measured by its excretion into the urine). Another study in 10 healthy subjects found that an antacid containing aluminium hydroxide, magnesium carbonate and magnesium hydroxide reduced the absorption of nitrofurantoin by 22%. ... 

Shiba K, Saito A, Shimada J, Hori S, Kaji M, Miyahara T, Kusajima H, Kaneko S, Saito S, Uchida H, Interactions of fleroxacin with dried aluminium hydroxide gel and probenecid. Rev InfectDis (1989) 11 (Suppl 5), S1097-S1098,... 

When 5 healthy subjects took a single 600-mg dose of rifampicin with various antacids the absorption of rifampicin was reduced. The antacids caused a fall in the urinary excretion of rifampicin as follows 15 or 30 mL of aluminium hydroxide gel 29 to 31% 2 or 4 g of magnesium trisilicate 31 to 36% and 2 g of sodium bicarbonate 21%. ... 

A study in 5 patients and 6 healthy subjeets found that within 48 hours of starting to take about 10 mL of aluminium hydroxide gel (Amphoget) every 6 hours with chlortetracycline 500 mg the serum levels of the antibae-terial were redueed by 80 to 90%. One patient had a reeurrenee of her urinary traet infeetion, which only subsided when the antacid was withdrawn, and one patient maintained chlortetracycline levels despite antacid treatment. Similar results were obtained in other studies. ... 

Aluminium hydroxide gel 30 mL did not affect the plasma level of a single 40-mg dose of propranolol in 6 healthy subjects the reduction in exercise heart rate was also unaffected. In contrast, a study in 5 healthy subjects found that 30 mL of an aluminium hydroxide gel reduced the levels and AUC of a single 80-mg dose of propranolol by almost 60%. In vitro and animal data suggest that bismuth subsalicylate, kaolin-pectin and magnesium trisilicate can also reduce the absorption of propranolol. ... 

A number of reports describe the development of hard putty-like or creamy precipitations and encrustations that have blocked the oesophagus or stomach of patients given sucralfate with enteral feeds (Ensure Pbis Fresubin plus F or Osmolit ). Another patient developed this precipitate when treated with Isocal and sucralfate with aluminium/magnesium hydroxide. Similarly, a patient receiving Pubnocare nasogastric feed, sucralfate and aluminium hydroxide gel also developed an oesophageal be-zoar, which was analysed and found to contain components of both the drugs and the enteral feed. ... 

In vitro studies also found that aluminium hydroxide gel and magnesium oxide can cause a significant reduction in tacrolimus concentrations due to pH-mediated degradation and as a result it was suggested that the administration of antacids and tacrolimus should be separated. ... 

In a single-dose crossover study in 6 healthy subjects, 30 inL of aluminium hydroxide gel did not affect the total amount of pseudoephedrine absorbed from a single 60-mg dose over 24 hours, but the rate of absorption was significantly increased during the first 3 hours. Conversely, 30 rriL of a 30% suspension of kaolin redueed the amount of pseudoephedrine absorbed from a single 60-mg dose by just 10%. The rate of absorption was also decreased. ... 

Lucarotti RL, Colaizzi JL, Baity H, Poust RI. Enhanced pseudoephedrine absorption by concurrent administration of aluminium hydroxide gel in humans. JP/iawi-S d (1972) 61,903-5. 

Lohmann A, Grobara P, Dingier E. Investigation of the possible influence of the absorption of vinpocetine with concomitant application of magnesium-aluminium-hydroxide gel. Arzneim-... 

The chloride content of pharmaceutical-grade aluminium hydroxide gels has been determined with a chloride ion-selective electrode on an aqueous suspension of the material [405]. 

Adsorption of Colloids by Other Substances. — Cases where a colloid can be completely removed from a liquid by porous bodies, powder, or jelly-like substances, are of common occurrence.J Colloidal gold can be separated from the liquid by animal charcoal, barium sulfate, or aluminium hydroxide gels. The process may be followed... 

Aluminium hydroxide gel and dried aluminium hydroxide gel may be assayed by the following method ... 

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