Slow-release tablets

Usually these products are oxidizers, and considerable success has been established over the years in small cooling systems, with mixed oxidizers of differing ratios, available as slow-release tablet (puck) and stick forms [such as l-bromo-3-chloro-5,5-dimethylhydantoin (BCDMH)]. These solid products are usually retained in a GRP (glass-reinforced plastic) or PVC (polyvinyl chloride) tank, often called a brominator. ... 

Potassium chloride is irritating to the gastrointestinal tract, even to the extent of causing perforation (4). In a retrospective study at surgical clinics in Stockholm County there were 22 cases of small-bowel ulceration in which a connection with slow-release potassium chloride tablets was probable (5). Most of the ulcers had caused stenosis of 1-2 cm of gut, and in four cases there was also perforation of the bowel wall. Five patients had perforation without signs of stenosis. Mortality was 27%. The pathology of the ulcers was similar to that described after use of enteric-coated potassium chloride tablets. The frequency of potassium-induced ulceration is low (about 3 cases per 100 000 patient-years of slow-release tablet use), but this complication can be serious. 

McGinity JW, Harris MR. Optimization of slow-release tablet formulations containing montmorillonite I properties of tablets. Drug Dev Ind Pharm 1980 6 399 10. 

Bottenberg P, Cleymaet R, de Muynck C, et al. Development and testing of bioadhesive, fluoride-containing slow-release tablets for oral use. / Pharm Pharmacol 1991 43 457-464. 

Mohammed FA, Kheder H. Preparation and in vitro/in vivo evaluations of the buccal bioadhesive properties of slow-release tablets containing miconazole nitrate. Drug Dev Ind Pharm 2003 29(3) 321-337. 

Sodium Chloride/Sodium Bicarbonate/Potassium Chloride with Bisacodyl Slow Release Tablets... 

PHENDIMETRAZINE TARTRATE (Bontril PDM tablets 35 mg, Bontril slow-release tablets 35 mg, Melfiat-105 Unicelles tablets 35 mg, Prelu-2 capsules, sustained release 105 mg)... 

Table 10.2 Formulation of a Slow Release Tablet Plan and Responses (1)...

Oral dosage forms include solutions as well as immediate-release and slow-release tablets and capsules. Since theophylline is cleared from the body relatively rapidly, particularly in children, slow-release formulations have been developed that minimize fluctuations in steady-state serum concentrations during an 8- to 12-h... 

Aripiprazole 30 mg daily was given to 7 healthy subjeets for 5 weeks, with lithium carbonate slow-release tablets 1.2 to 1.8 g daily (to give a plasma level of 1 to 1.4 mmol/L) for weeks 3 to 5 of the study. The mean AUC and maximum plasma coneentrations of aripiprazole were found to increase by 15% and 19%, respeetively, but these ehanges were not eon-sidered to be clinically significant. ... 

Food enhanced the bioavailability of a single 50-mg dose of hydralazine in healthy subjects by two to threefold in one study. Similar findings were reported by the same research group with conventional hydralazine tablets, but not slow-release tablets. In contrast, others found that food had no effect on the AUC of hydralazine in healthy subjects. Furthermore, other studies have found that food decreases the AUC of hydralazine by 46% when it is given as oral solution, by 44% after conventional tablets, and by 29% (not significant) after a slow-release preparation. A reduction in the antihypertensive effect of hydralazine was noted in the first of these studies, but no significant alteration in antihypertensive effect was seen in the second. Similarly, another study reported a decrease in the AUC of hydralazine of 55% when it was given with a meal, and 62% when it was... 

High dosing frequency (three or more times daily) due to their rapid elimination or excretion. Under normal circumstances the elimination will be slower than the absorption rate of the active substance. As a result of this difference, the elimination is reflected in the descending part of the blood concentration versus time curve. A fast elimination rate however would require it to be administered several (more than three to four) times a day. Slow release of the active substance from the dosage form (e.g. a slow release tablet) will cause the absorption rate to become slower than the elimination rate. As a consequence the elimination phase in the blood concentration versus time curve no longer reflects the elimination rate, but rather the absorption rate of the active substance, whereas the initial rising phase in the curve is a reflection of the elimination rate of the active... 

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