Determination of Panthenol in Pharmaceutical Preparations by Microbiological Assay with Escherichia coli 99-4

Preliminary Solvent Extraction for the Spectrophotometric Determination of Panthenol in Pharmaceutical Products

“…Another series of 10 samples, which had previously been assayed by Rogers and Campbell in this laboratory using both their microbiological method (5) and that of Bird and McCready (I), gave comparable results by the proposed method, as shown in Table II.…”

“…For samples between 5 and 50 p.p.m., only 10~7 gram of glucose react during the measurement interval, so that the precision in terms of the amount reacted is about 10~9 gram. The development of precision nullpoint potentiometry (PNPP) has demonstrated the usefulness of precise potentiometric measurements for quantitative determinations, especially in the micro range (5,6). With the PNPP method, it has been possible in many cases to determine constituents at the part per million level with reproducibility and accuracy of 0.1%.…”

“…Recent work by the authors (5) demonstrated the application of PNPP for iodometric procedures, including its application for the determination of micro amounts of hydrogen peroxide. The work of Malmstadt and Hicks (4) with a spectrophotometric reaction-rate procedure showed that within a few seconds after the start of the reaction, the rate of change of hydrogen peroxide from the specific oxidation of glucose was proportional to the glucose concentration, at least over a fewfold range.…”