PubMed Health⌕ Search

Biomedical subjects

R L Everett

Publications and source records attributed to R L Everett.

4 recordsLinked to original sources
PubMed1989

In vitro dissolution profile of water-insoluble drug dosage forms in the presence of surfactants.

The determination of the in vitro release profile of water-insoluble drug products requires dissolution media different from those used for water-soluble drug products. Since the relevance of drug dissolution in organic solvents is questionable, we investigated the use of surfactants to determine the dissolution profiles of water-insoluble drug products. In most cases, the drug dissolution rate and extent increased as the surfactant concentration in the aqueous dissolution medium increased. Suitable dissolution profiles were obtained in the presence of sodium lauryl sulfate (SLS) for water-insoluble drug products, such as griseofulvin, carbamazepine, clofibrate, medroxyprogesterone, and cortisone acetate. These findings recommend the use of surfactants for determining the aqueous dissolution of water-insoluble drug products rather than adding organic solvents to the dissolution medium.

Capsules↗
PubMed1979

Automated detection of EEG artifacts during sleep: preprocessing for all-night spectral analysis.

This paper describes a simple artifact detection algorithm which can be used when large amounts of EEG data are to be automatically processed via spectral analysis techniques in a general purpose digital computer, and visual inspection of each EEG epoch becomes an impossible task. The technique is based on a chi-square (chi(2)) goodness-of-fit test to a Gaussian distribution (CSQ), and it was applied to EEG epochs each 30 sec long. This test proved to be very sensitive to non-stationarities in the EEG amplitude distribution for a particular epoch, and it produced a large value for the chi(2) coefficient when an artifact was present. EEG epochs that gave rise to chi(2) coefficients of value larger than a heuristically determined minimum were discarded from further analysis. The above technique enabled efficient data reduction and reliable automatic off-line processing of 50 nights of sleep EEG via spectral techniques.

Action Potentials↗
PubMedDate not supplied

Liquid chromatographic determination of chlorpropamide in tablet dosage forms: collaborative study.

A reverse-phase liquid chromatographic method was developed for determining chlorpropamide in tablet dosage forms. Linearity was established over the range 0.2-2.0 micrograms at a wavelength of 240 nm. The Associate Referee obtained a mean recovery for a synthetic tablet mixture of 99.2%, with a relative standard deviation (RSD) of 1.41. For an authentic tablet mixture, collaborators obtained a mean recovery of 99.6% with an RSD of 0.60%. RSDs were 1.24% for 250 mg/tablet commercial product and also for 100 mg/tablet commercial product. The method has been adopted official first action.

Chlorpropamide↗