[Analysis of anisodine and its metabolites in rat plasma by liquid chromatography-tandem mass spectrometry].

AIM: To identify anisodine and its metabolites in rat plasma after ingestion of anisodine by combining liquid chromatography and tandem mass spectrometry (LC-MS(n)). METHODS: Plasma samples from rats after a single orally administration of 20 mg anisodine were added with methanol to precipitate protein. Then, it was analyzed by LC-MS(n). Identification and structural elucidation of the metabolites were performed by comparing their changes in molecular masses, retention-times and full scan MS(n) spectra with those of the parent drug and blank plasma. RESULTS: The results revealed that the parent drug and its four metabolites (norscopine, scopine, hydroxyanisodine, N-oxide anisodine) existed in rat plasma. CONCLUSION: This method is sensitive, rapid, simple, and it is suitable for the rapid identification of drug and its metabolits.

A rapid and sensitive liquid chromatography/positive ion tandem mass spectrometry method for the determination of cimetropium in human plasma by liquid-liquid extraction.

We have developed and validated a simple detection system with high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometry (ESI-MS/MS) for determining cimetropium levels in human plasma using scopolamine butyl bromide as an internal standard (I.S.). The acquisition was performed in the multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 357.9 > 103.1 for cimetropium and m/z 359.9 > 103.1 for butyl-scopolamine. The method involves a simple single-step liquid-liquid extraction with dichloromethane. The analyte was chromatographed on an YMC C18 reversed-phase chromatographic column by isocratic elution with 10 mM ammonium formate buffer-methanol (19:81, v/v; adjusted to pH 4.0 with formic acid). The results were linear over the studied range (0.2-100 ng ml(-1)), with r2 = 1.0000, and the total analysis time for each run was 2 min. Intra- and interassay precisions were 0.70-8.54% and 1.08-4.85%, respectively, and intra- and interassay accuracies were 97.56-108.23% and 97.48-103.91%, respectively. The lower limit of quantification (LLOQ) was 0.2 ng ml(-1). At this concentration, mean intra- and interassay precisions were 8.54% and 4.85%, respectively, and mean intra- and interassay accuracies were 97.56% and 98.91%, respectively. The mean recovery ranged from 62.71 +/- 4.06 to 64.23 +/- 2.32%. Cimetropium was found to be stable in plasma samples under typical storage and processing conditions. The devised assay was successfully applied to a pharmacokinetic study of cimetropium bromide administered as a single oral dose (150 mg) to healthy volunteers.

Determination of the main tropane alkaloids from transformed Hyoscyamus muticus plants by capillary zone electrophoresis.

A capillary zone electrophoretic method (CZE) was developed using an uncoated fused silica capillary for the separation and determination of the main tropane alkaloids. The applicability of the developed method for analysis of plant samples was examined by analyzing samples of transgenic Egyptian henbane Hyoscyamus muticus (L.) plants. A simple 40 mM phosphate buffer at pH 7.8 using a voltage of 20 kV was found the best for this purpose. The main tropane alkaloids, atropine and scopolamine as well as nor-(-)-scopolamine, and tropic acid, the precursor of tropane alkaloids, could be separated in less than 13 min. The linear concentration range for atropine was 5.00-140 microg ml(-1), for scopolamine 7.50-210 microg ml(-1) and for tropic acid 2.50-70.0 microg ml(-1).

Rapid and efficient purification of cimetropium bromide and mifentidine drug metabolite mixtures derived from microsomal incubates for analysis by mass spectrometry.

A comparative study of the use of organic solvent extraction versus Sep-Pak C18 cartridges in the recovery and analysis of phase I (unconjugated) drug metabolites using mass spectrometry is presented. Standard mixtures of putative metabolites of the anticholinergic drug cimetropium bromide and the H2-antagonist mifentidine were purified from inactivated liver microsomal preparations using both methods, and subsequently the recovery of each compound was quantitated. In general, the percentage recovery and degree of purification were greater when using Sep-Pak C18 cartridges compared with organic solvent extraction. Even more efficient recovery was achieved when zinc sulphate precipitation of proteins in the liver microsomal mixtures was carried out prior to analysis. Also, the HPLC-grade solvents used in this study contained a variety of ultraviolet-inactive, hydrophobic components. This leads to problems of suppression in fast atom bombardment mass spectrometric analysis. Using Sep-Pak C18 cartridges directly prior to analysis by fast atom bombardment with single or tandem mass spectrometry leads to far superior mass spectral results compared with organic solvent extraction.

[Study on separation and determination of four tropane alkaloids in crude drugs by micellar HPLC].

A new method for separation and determination of four important tropane alkaloids (hyoscyamine, scopolamine, anisodamine and anisodine) in crude drugs by micellar HPLC was developed. The mobile phase was optimized with the modified simplex method (MSM). The chromatographic response function (CRF) was used as the criterion of optimization and three dimension simplex was used in this course. After eight tests, the given accuracy was achieved. In the optimized system the four tropane alkaloids are separated not only from each other but also from the interfering components in the crude drugs. The CMC of SDS in mobile phase was determined to be 5 mmol/L by circle method. The experimental evidences show that the optimized system is micellar chromatography. This method is simple, sensitive and accurate. The extraction solution can be injected directly without the need of a general purification procedure. Several plant materials containing tropane alkaloids were determined. The results and chromatograms are reported in this paper.