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R Jannasch

Publications and source records attributed to R Jannasch.

6 recordsLinked to original sources
PubMed1986

[Capillary isotachophoresis--a new method in drug analysis. 3. Analytic capillary isotachophoresis for the determination of amantadine and rimantadine].

Investigations by means of analytical capillary isotachophoresis are possible not only for ampholytes, as peptides or amino acids, but generally for weak and strong electrolytes. Amantadine and rimantadine are determined by making use of a leading electrolyte including K+ ions at a pH range from 5.9 to 6.0 (terminating ion = creatinine+) at concentrations of the test solutions of greater than or equal to 600 nmol/ml and greater than or equal to nmol/ml, respectively, with a precision calculated as rel. S.D. (%) less than +/- 3 as a rule and a duration for one analysis less than 10 min. The tested discontinuous electrolyte system enables the determination of both the active substances simultaneously. The missing UV absorption of 1 and 2 is not disadvantageous by virtue of the application of the conductivity detector. The method was employed to carry out a content uniformity test for 2 tablets and informing experiments about the dissolution of 2 hydrochloride respectively 1 hydrochloride in water out of tablets and capsules, respectively.

Adamantane↗
PubMed1985

[Capillary isotachophoresis--a new method in drug analysis. 2. Analytical capillary isotachophoresis of the synthetic peptide substance P].

For the synthetic undecapeptide substance P being object of actual pharmacological research and a potential peptide-drug experiments were carried out for the assessment of cation analyses by means of capillary isotachophoresis for the purpose of the development of test methods for pharmaceutical judgments of quality. Best conditions exist at a pH range from 6.2 to 6.3 of the leading electrolyte of the discontinuous electrolyte system by using of the counter ion morpholinoethansulfonic acid. The results confirm the high separation efficiency and rate of information of such analyses in the field of peptides. They served the control of purification methods for substance P as well as the determination of the contents in preparations for this peptide including simultaneously in case of need the preservative benzalkonium chloride with sufficient reproducibility (rel. S.D. 0.7-2.7% for substance P and less than or equal to 3% for benzalkonium chloride). It is also possible to estimate impurities and products of decomposition respectively down to the level of 0.1-1% and following that to make statements about the stability.

Benzalkonium Compounds↗