PubMed Health⌕ Search

Biomedical subjects

R F Shangraw

Publications and source records attributed to R F Shangraw.

At least 19 recordsLinked to original sources
PubMed1989

Variable efficacy of calcium carbonate tablets.

Orally administered calcium carbonate tablets are commonly prescribed as a calcium supplement and for their phosphate-binding effects in renal failure patients. Two cases are reported in which a commercially available brand of calcium carbonate tablets appeared to be ineffective. Formal investigation of the bioavailability of this product revealed it to have impaired disintegration and dissolution and a lack of clinical efficacy. Recommendations that will enable physicians to avoid prescribing and pharmacists to avoid dispensing ineffective calcium carbonate tablets are proposed.

Adult↗
PubMed1983

Thiazides. VIII: Dissolution survey of marketed hydrochlorothiazide tablets.

The dissolution profiles of 50-mg hydrochlorothiazide tablets representing all approved manufacturers (at the time of the study) were determined in two vehicles [purified water and dilute (1:100) hydrochloric acid] by three methods (rotating basket at 150 rpm; spin filter at 300 rpm; paddle method at 50 rpm). The paddle method was preferred on the basis of overall ease of operation, reproducibility, and discrimination. The paddle data were validated in both vehicles on the same lots of tablets by a second laboratory. A standard of not less than 80% dissolution in 60 min by the paddle method in water is proposed for hydrochlorothiazide tablets.

Chemistry, Pharmaceutical↗
PubMed1977

Moisture permeation of typical unit does repackaging materials.

The moisture permeation of unit does repackaging materials used by various hospital and community pharmacies in a metropolitan area was studied. Commercial desiccant pellets were packaged in the same manner used for ordinary tablets and capsules. The samples were weighed and placed in a controlled chamber at about 75% relative humidity and 22 C, and tested for weight gain over a period of 4-10 days. Four types of packages were evaluated: (1) heat-sealed polyethylene bag, (2) polyvinyl chloride cups adhesive-sealed to multiple-ply paper, (3) heat-sealed "polycel-polyfoil" strip packages and (4) polyvinyl chloride/foil multiple-cup blister packs. A wide range of results was found. None of the containers tested was a good moisture barrier, although some offered protection for a limited time. Several needs were identified by this survey. Pharmacists need more information and an increased awareness concerning the permeation characteristics of repackaging materials, suitable operating procedures and the stability of pharmaceutical products. Standards must be established for repackaging materials as well as limits on storage periods for the repackaged pharmaceuticals. Procedures for pharmacists to test their own packaging systems, and a checklist of some important guidelines for repackaging in unit dose containers, are presented.

Drug Packaging↗