[Comparative dissolution test of modified release pharmaceutical products for potassium replacement]. / Kálium pótlására használatos késleltetett hatóanyag-leadású gyógyszerek összehasonlító kioldódási vizsgálata.

INTRODUCTION: Oral potassium replacement is still inevitable. To reduce the irritation of the gastric and intestinal mucosa, pellet and matrix based formulations ensuring extended release of potassium chloride are used. The dissolution tests may help to understand the in vivo steps of the release of potassium chloride and the absorption of potassium. AIM: Using dissolution tests extended to 12 hours the authors evaluated potassium chloride release characteristics of pellet and matrix tablet based formulations used for potassium replacement. METHOD: The tests were performed in line with the CPMP/EWP/QWP/1401/98 guideline at nine time points (0, 1, 2, 3, 4, 5, 7, 9 and 12 hours) in three dissolution media (0.1 M hydrochloric acid, pH 1.2; acetate buffer, pH 4.5; phosphate buffer, pH 6.8). RESULTS: Similar results were found in all three dissolution media. CONCLUSIONS: It is conceivable, that the release of potassium chloride begins already in the stomach (pH = 1.2) and at an average speed of gastrointestinal transit - in about 6-7 hours - 80% of the potassium chloride content of both formulations is dissolved by the time of the entrance to the large bowel. It seems likely, that in vivo in the proximal section of the gastrointestinal tract more potassium chloride is dissolved out of the matrix based formulation, than from the pellet based one. Both formulations meet the clinical requirements of the effective potassium chloride release.

Preventing hypokalemia in critically ill patients.

BACKGROUND: Many therapies used in critical care cause potassium depletion. Current practice relies on potassium replacement protocols after a patient becomes hypokalemic. Potassium bolus therapy creates risk for patients, is costly, and increases nurses' workload. OBJECTIVES: To determine if administering potassium preemptively in maintenance intravenous fluid would prevent episodes of hypokalemia and reduce the need for potassium boluses. METHODS: Medical records of 267 patients with normal potassium and creatinine levels at admission who did not receive total parenteral nutrition were reviewed. The 156 patients who met the study criteria were categorized by group: those who received potassium via maintenance intravenous fluid (treatment; n = 76) and those who did not (control; n = 80). The treatment group had potassium chloride or acetate added to intravenous fluid delivered at 36 to 72 mmol/d. RESULTS: The 2 groups did not differ significantly in age, race, sex, or admitting diagnosis. Type of diagnosis, length of stay, and potassium and creatinine levels at admission did not affect the number of potassium boluses for either group. The patients given maintenance potassium preemptively received significantly fewer (P < .001) potassium boluses (0.8) than did the control group (2.73), for a mean savings of $231 per patient for the treatment group. CONCLUSIONS: Patients with normal potassium and creatinine levels at admission benefitted from a maintenance intravenous dose of potassium of 72 to 144 mmol/L per day. Compared with control patients, patients receiving this dose avoided detrimental hypokalemic events, had fewer invasive procedures and lower costs, and required less nursing care.

Antibacterial activity of citrate and acetate.

OBJECTIVE: We evaluated citrate salt, acetate salt, and their combinations for antibacterial activity against a sample of common pathogens. METHODS: Bacterial suspensions were added to serial microdilutions of the salts in broth, with final cell concentrations of 10(4-5) colony-forming units per milliliter. After overnight incubation at 35 degrees C, the minimum inhibitory concentration was recorded. Bactericidal activity was screened by quantitative subcultures from the minimum inhibitory concentration dilution. RESULTS: Citrate salt was active against gram-positive species and Candida albicans but showed little activity against gram-negative species; acetate salt showed the opposite results. Their combination did not show synergism or antagonism. CONCLUSION: It may be feasible to take advantage of the different antibacterial spectra of these two agents and combine them for possible application such as food or medical preservative agents.