Moisture permeation of newer unit dose repackaging materials.

Moisture permeation of some unit dose repackaging materials currently available was tested and compared with the results of an earlier study. Seventeen unit dose containers marketed for hospital pharmacy repackaging were tested. Most of the samples were prepared in a laboratory under optimal physical and mechanical conditions. The methodology involved packaging a desiccant pellet, storage at 75 +/- 3% relative humidity and 20 +/- 2 C, and weighing at various time intervals. Each container was placed into one of four classes depending upon the amount of weight gain. In general, moisture permeation values for all types of materials were much lower than in the previous study. The results show that improved moisture protection can be achieved through modifications in typical repackaging systems.

Chromatographic assays for folic acid.

TLC and high-pressure liquid chromatographic (HPLC) assays for folic acid were developed. In the TLC procedure, the folic acid band was extracted from the silica gel after development and determined spectrophotometrically by an oxidation and Bratton-Marshall sequence. A column packed with octadecylsilane chemically bonded to microparticulate silica gel was used for the HPLC assay. Potentiometric determination of water in folic acid samples was necessary to obtain accurate purity values. In a comparison of four assay methods, a direct colorimetric method gave precise, but unspecific, results, while the USP XIX colorimetric method lacked both precision and specificity. The two chromatographic methods were both precise and specific and gave the same assay results. Both methods separated p-aminobenzoic acid, N-(p-amino-benzoyl)-L-glutamic acid, 2-amino-1,4-dihydro-4-oxo-6-pteridinecarboxylic acid, 2-amino-4(1H)-pteridinone, and several unidentified impurities from folic acid.

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.