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Biomedical subjects

D W Newton

Publications and source records attributed to D W Newton.

At least 19 recordsLinked to original sources
PubMed1992

Prospects for controlled-delivery systems.

Americans seem to view medical progress as a citizen's entitlement. They expect, and researchers expect to seek, cures for acquired immunodeficiency syndrome (AIDS), Alzheimer's disease, cancer, and other deadly or incapacitating diseases. Both the public and researchers also seem undaunted by the cost. CDS technologies and biotechnology drugs are making this expectation possible. Still, CDSs may not dispel public resentment over the high cost--and profit--of discovering otherwise welcomed new healing molecules. As noted by 1988 Nobel laureate in medicine, Sir James Black: "I think both the press and industry have failed to communicate to the public that behind every little pill is a vast amount of high technology...." With increasing use of and satisfaction from CDSs, more of these mechanisms, covering a broadening spectrum of uses, will be marketed. Because these products are taken less often, patient compliance is expected to increase. As more CDSs are introduced, dispensing frequency will decline and the complexity of prescription drugs will increase. Pharmacists can take advantage of this trend by expanding their activities in the management their patients' medication use.

Dosage Forms↗
PubMed1978

Potential source of error in official diazepam assays.

A possible source of interference by a benzophenone hydrolysis product with the USP XIX spectrophotometric determination of diazepam in dosages forms is reported. A minor adaptation of the official assay procedures is briefly proposed as one method to correct this error.

Diazepam↗
PubMed1978

Physicochemical determinants of incompatibility and instability in injectable drug solutions and admixtures.

Several physicochemical conditions or phenomena most commonly causing incompatibility, instability or related difficulties in parenteral drug solutions and admixtures are reviewed. The following factors involved in chemical incompatibilities are reviewed: concentration, pH, acid-base character, reduction-oxidation, photolysis, epimerization, temperature, dextrose catalysis and hydrolysis. The following factors involved in visual incompatibilities are discussed: pH, acid-base character, solvent system, color change, complexation, adsorption and adherence, dissolution rate, salting-out and leaching, and foaming. Pharmacists may recognize, predict and avoid parenteral imcompatibilities based on their experience, an understanding of physicochemical principles and reference to pertinent publications.

Chemical Phenomena↗
PubMed1977

Characteristics of medicated and unmedicated microglobules recovered from complex coacervates of gelatin-acacia.

Medicated and unmedicated microglobules prepared from complex coacervates of Type A gelatin and acacia were recovered as water-insoluble powders consisting of discrete units, which were spontaneously revertible to highly disperse systems when suspended in water or physiological electrolyte solutions. Spherical microglobules containing up to 15% (w/w) sulfamerazine had a nominal diameter of 30 micron in aqueous suspension. Larger but irregularly shaped products containing up to 45% (w/w) sulfamerazine were also recovered. The relationships of the weight of sulfamerazine added per coacervate batch to weight yield and percent (w/w) included sulfamerazine of the microglobules were both linear.

Acacia↗
PubMed1976

Limitations of compounding diazepam suspensions from tablets.

The concentration of diazepam in two types of suspension vehicles, as prepared from 10-mg tablets was tested over a 14-day period. The suspensions (1 mg/ml) were stored at room temperature in amber glass bottles. In one suspension, consisting of eight triturated tablets, 4.0 ml ethanol, 24.0 ml propylene glycol, 20.0 ml Syrup, USP, and 32.0 ml chocolate syrup, 90% of the diazepam was dissolved. This suspension demonstrated consistently acceptable concentrations of diazepam. In the other suspension, consisting of triturated tablets and Syrup, USP, only 25% of the diazepam was dissolved, and less consistent, subpotent concentrations of diazepam were found. The variation of diazepam concentrations between the suspensions was unrelated to the chemical stability of the drug.

Diazepam↗
PubMed1975

Evaluation of preparations of patent blue (Alphazurine 2G) dye for parenteral use.

The stability and the behavior of patent blue (Alphazurine 2G) dye in a vehicle such as lidocaine hydrochloride injection were studied with regard to medication orders which may be prepared by hospital pharmacists. The patent blue family of dyes are sulfonated diaminotriphenylmethane, vital, acid dyes which have been used as diagnostic aids in both lymphography and burn debridement. A literature review, including some toxicological information, is presented. The occurrence of the sodium salt form and the equilibrium solubility of the patent blue sample studied are reported. Some implications of patent blue injections include: Clinical literature reports of toxicities, the unapproved status of patent blue by the Food and Drug Administration, results of stability studies, and the formation of viscid, water-insoluble precipitates of patent blue in combination with lidocaine hydrochloride. The extemporaneous preparation and subsequent use of parenteral prescriptions of patent blue dye in vehicles containing lidocaine hydrochloride and methylparaben are not recommended.

Aniline Compounds↗