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S Ebel

Publications and source records attributed to S Ebel.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Determination of the release of drugs from transdermal therapeutic systems. Presentation of a new release system].

A relatively simple release model for transdermal therapeutic systems (TTS) is described. The TTS is separated from the elution solvent by a semipermeable membrane. The elution solvent passes an elution channel with a flow rate of 3-9 ml/h. For the quantitative determination of the drug HPLC or UV spectrometry are used. Depending on the active drug and the design of the TTS, different releasing kinetics are observed. While diclofenac follows approximately a zero order kinetic, the respective kinetic for mepindolol roughly follows a diffusion controlled square root of t-order.

Administration, Cutaneous↗
PubMed1980

Single-dose pharmacokinetics of macrocrystalline nitrofurantoin formulations.

The pharmacokinetics of macrocrystalline formulations of nitrofurantoin (50 mg and 150 mg) were studied after single dose administration in 10 healthy male volunteers, using a cross-over study design. The total estimation of the pharmacokinetic data was calculated simultaneously from all of the single values, using a direct search procedure based on an open two-compartment-model (with additional 2 first-order input steps for one of the 150 mg formulations). Analysis showed that the relevant pharmacokinetic parameters for the formulations studied were in comparable ranges; however, the terminal elimination half-lives, 1.2 h and 1.7 h, were 3 to 4 times longer in comparison to those currently reported in the literature. The marked discrepancy in these findings is discussed and a review of the current data on the elimination kinetics of nitrofurantoin is recommended.

Adult↗
PubMed1980

[Multiple-dose pharmacokinetics of paracetamol and salicylamide in man after combined rectal application (author's transl)].

The pharmacokinetic behaviour of paracetamol (300 mg) and salicylamide (200 mg) in the course of combined repetitive (three times tau = 4 h) administration of suppositories was investigated in 10 healthy, male volunteers. The estimation of the pharmacokinetic constants was performed by a simultaneous curve fitting from all single values with a direct search procedure, based on an open two-compartment model and the multiple-dose equation. Both drugs showed a pharmacokinetic behaviour which was conformable to the literature data for single dose and mono substance applications. The dynamics of the absorption kinetics was decreased, as is generally seen after the application of suppositories. In spite of this both substances reached a steady state after the 3rd application. A calculation of collapse coefficients showed for paracetamol as well as for salicylamide a pharmacokinetic distribution behaviour deviating from an open one-compartment model. Due to the good conformity of the parameters, which causes the synchronism of the time-concentration curves after multiple dose application, paracetamol and salicylamide are suited combination partners as seen from a pharmacokinetic point of view.

Acetaminophen↗
PubMed1979

[Analytical data and preparation of important 3-hydroxy-5-phenyl-1,4-benzodiazepin-2-one derivatives (author's transl)].

The article describes analytical data (TLC, IR, MS) of 7-chloro-1-methyl-1,3-hydroxy-5-phenyl-2H-1,4-benzodiazepin-2-one (3-hydroxydiazepam) and 7-cyclopropyl-methyl-1,3-dihydro-3-hydroxy-5-phenyl-2H-1,4-benzodiazpin-2-one (3-hydroxy-prazepam). Analytical properties of important derivatives (N-oxides, 3-acetoxy compounds, re-arrangement products) are also reported. Besides preparation methods are given for the synthesis of these substances, considering in particular preparation as solution-reactions as well as reaction on the TLC-plate.

Benzodiazepinones↗
PubMed1978

[Studies on the analysis of nifedipine considering in particular transformation products formed by light exposition (author's transl)].

Under the influence of light (VIS and UV) on thin-layer plates and in liquid solutions, 1,4-dihydro-2,6-dimethyl-4-(0-nitro-phenyl)-pyridine-3,5-carboxylic acid dimethylester (nifedipine, Adalat) is converted to the nitroso compound 4-(2-'nitrosophenyl)-2,6-dimethyl-3,5-dicarbomethoxy-pyridine. The article also describes TLC-, GLC-, UV-, IR- and MS-data of nifedipine, the nitroso and the nitro derivative.

Chemical Phenomena↗