Stability of norfloxacin in an extemporaneously prepared oral liquid.

The stability of norfloxacin in an extemporaneously prepared suspension stored at room temperature and under refrigeration was studied over 56 days. A 20-mg/mL suspension was prepared from commercially available 400-mg norfloxacin tablets and equal amounts of Ora-Plus and strawberry syrup to make a final volume of 60 mL. Six identical samples of the suspension were prepared in amber plastic prescription bottles. Three were stored at room temperature (23-25 degrees C) and three under refrigeration (3-5 degrees C). Immediately after preparation and at 7, 14, 28, and 56 days, the samples were assayed in duplicate by stability-indicating high performance liquid chromatography. The samples were also inspected for color and odor changes and the pH of each sample was determined. At least 93% of the initial norfloxacin concentration remained throughout the 56-day study period. The color, odor, and pH of all of the samples did not change appreciably. An extemporaneously prepared suspension of norfloxacin 20 mg/mL was stable for at least 56 days when stored at either 23-25 or 3-5 degrees C.

Behavioral effects of aluminum ingestion on animal and human subjects.

Abnormally high brain aluminum concentrations have been detected in hemodialysis patients who died of an unexplained encephalopathy. As a result, this study was undertaken to examine whether the ingestion of aluminum produces behavioral aberrations in non-dialysed human subjects and rats with ostensibly normal renal function. Rats were fed AlCl3 by intubation in varying doses, and tests measuring learning ability, visual temporal acuity, motor coordination and activity were administered. It was found that orally ingested aluminum is absorbed by rats and deposited in the brain. High brain aluminum levels are associated with rapid general activity, decreased ability to maintain roto-rod activity, and increased sensitivity to flicker. Behavioral tests were also given to elderly human subjects and performance correlated with serum aluminum level. High serum levels of aluminum in elderly humans are associated with impaired visuo-motor coordination, poor long-term memory, and increased sensitivity to flicker.

Polywater: methods for identifying polywater columns and evidence for ordered growth.

The refractive indices of polywater columns in glass capillaries have been rapidly and accurately measured with an interference microscope. Polywater has been detected by this method in both quartz and Vycor glass capillaries. A comparison of refractive index measurements with measurements of optical anisotropy indicates that polywater initially condenses with an ordered structure.