GC-MS analysis of organic fractions of Chrozophora tinctoria (L.) A.Juss. and their prokinetic propensity in animal models.

Chrozophora tinctoria (L.) A.Juss. is herbaceous, monecious annual plant used traditionally to cure gastrointestinal disorders. The present study was carried out to find the bioactive compounds by Gas Chromatography-Mass Spectrometry, the acetylcholinesterase inhibitory potential acute toxicity, and emetic activity present in the ethyl acetate fraction of Chrozophora tinctoria (EAFCT) and dichloromethane fraction of Chrozophora tinctoria (DCMFCT). The compounds detected in both fractions were mostly fatty acids, with about seven compounds in EAFCT and 10 in DCMFCT. These included pharmacologically active compounds such as imipramine, used to treat depression, or hexadecanoic acid methyl ester, an antioxidant, nematicide, pesticide, hypocholesterolemic, 9,12,15-Octadecatrienoic acid, ethyl ester, (Z,Z,Z)- is used as a cancer preventive, antiarthritic, antihistaminic, hepatoprotective, insectifuge, nematicide, Pentadecanoic acid, 14-methyl-, methyl ester have antifungal, antimicrobial and antioxidant activities, 10-Octadecanoic acid, methyl ester have the property to decrease blood cholesterol, Antioxidant and antimicrobial, 1-Eicosanol is used as an antibacterial, 1-Hexadecene has antibacterial, antioxidant, and antifungal activities. Both DCMFCT and EAFCT fractions inhibited acetylcholinesterase (AChE) activity with IC50 values of 10 µg and 130 µg, respectively. Both the fractions were found to be toxic in a dose-dependent manner, inducing emesis at 0.5g onward and lethargy and mortality from 3-5 g upwards. Both the fractions combined with distilled water showed highly emetic activity. The significant increase in the number of vomits was shown by EAFCT plus distilled water which are 7.50±1.29, 7.25±3.10, and 11.75±2.22 number of vomits at 1g, 2g, and 3g/kg concentration respectively, while DCMFCT plus distilled water showed 5.25±2.22, 7.50±2.52 and 10.25±2.22 number of vomits at 1g, 2, and 3g/kg correspondingly. The antiemetic standard drug metoclopramide has a higher impact against the emesis induced by both the fractions than dimenhydrinate. Metoclopramide decreases the number of vomits caused by EAFCT to 1.00±0.00, 2.00±0.00, 4.00±1.00 at 1g, 2, and 3g/kg sequentially, while dimenhydrinate decreases the number of vomits to 1.33±0.58, 2.33±1.15, 4.33±0.58 at 1g, 2, and 3g respectively. In the same way, Metochloprimide decreases the number of emesis caused by DcmCt from 5.25±2.22, 7.50±2.52, 10.25±2.22 to 1.33±0.58, 2.33±1.1, 4.33±0.58 at 1g, 2, and 3g/kg concentrations. The present study is the first documented report that scientifically validates the folkloric use of Chrozophora tinctoria as an emetic agent.

Full spectrum and selected spectrum based chemometric methods for the simultaneous determination of Cinnarizine and Dimenhydrinate in laboratory prepared mixtures and pharmaceutical dosage form.

Three chemometric methods namely, concentration residual augmented classical least squares (CRACLS), spectral residual augmented classical least squares (SRACLS) and partial least squares (PLS) were applied for the simultaneous quantitative determination of Cinnarizine and Dimenhydrinate in their binary mixtures. All techniques were applied with and without variable selection using genetic algorithm (GA) resulting in six models (CRACLS, GA-CRACLS, SRACLS, GA-SRACLS, PLS, GA-PLS). These models were applied for the simultaneous determination of the drugs in their laboratory prepared mixtures and pharmaceutical dosage form via handling their UV spectral data. It was found that GA based models are simpler and more robust than those built with the full spectral data. The proposed models were found to be simple, fast and require no preliminary separation steps; so they can be used for the routine analysis of this binary mixture in quality control laboratories.

Simultaneous Determination of Cinnarizine and Dimenhydrinate in Binary Mixture Using Chromatographic Methods.

Two accurate and sensitive chromatographic methods have been developed and validated for simultaneous determination of cinnarizine (CIN) and dimenhydrinate (DIM). The first method uses simultaneous quantitative thin layer chromatography (TLC) spectrodensitometric evaluation of them, using ethyl acetate:methylene chloride (8 : 2 by volume) as a mobile phase. Chromatograms are scanned at 254 nm. This method analyzes CIN in a concentration range of 0.5-6 µg per band with mean percentage recovery of 99.78 ± 1.001 and DIM in a concentration range of 1-6 µg per band with mean percentage recovery of 99.87 ± 1.319. The second method is high-performance liquid chromatography using methanol:acetonitrile:water [85 : 10 : 5, by volume +0.5% tri ethyl amine (TEA)] as a mobile phase. The linearity was found to be in the range of 10-60 and 5-60 µg mL(-1) for CIN and DIM, respectively. The methods were successfully applied to the simultaneous determination of CIN and DIM in bulk powder, laboratory-prepared mixtures and pharmaceutical dosage forms. The validity of results was assessed by applying standard addition techniques. The results obtained are found to agree statistically with those obtained by a reported method, showing no significant difference with respect to accuracy and precision.

Development of normalized spectra manipulating spectrophotometric methods for simultaneous determination of Dimenhydrinate and Cinnarizine binary mixture.

Simultaneous determination of Dimenhydrinate (DIM) and Cinnarizine (CIN) binary mixture with simple procedures were applied. Three ratio manipulating spectrophotometric methods were proposed. Normalized spectrum was utilized as a divisor for simultaneous determination of both drugs with minimum manipulation steps. The proposed methods were simultaneous constant center (SCC), simultaneous derivative ratio spectrophotometry (S(1)DD) and ratio H-point standard addition method (RHPSAM). Peak amplitudes at isoabsorptive point in ratio spectra were measured for determination of total concentrations of DIM and CIN. For subsequent determination of DIM concentration, difference between peak amplitudes at 250 nm and 267 nm were used in SCC. While the peak amplitude at 275 nm of the first derivative ratio spectra were used in S(1)DD; then subtraction of DIM concentration from the total one provided the CIN concentration. The last RHPSAM was a dual wavelength method in which two calibrations were plotted at 220 nm and 230 nm. The coordinates of intersection point between the two calibration lines were corresponding to DIM and CIN concentrations. The proposed methods were successfully applied for combined dosage form analysis, Moreover statistical comparison between the proposed and reported spectrophotometric methods was applied.

Comparative study of spectrophotometric methods manipulating ratio spectra: an application on pharmaceutical binary mixture of cinnarizine and dimenhydrinate.

Four simple, specific, accurate and precise spectrophotometric methods are developed and validated for simultaneous determination of cinnarizine (CIN) and dimenhydrinate (DIM) in a binary mixture with overlapping spectra, without preliminary separation. The first method is dual wavelength spectrophotometry (DW), the second is a ratio difference spectrophotometric one (RD) which measures the difference in amplitudes between 250 and 270 nm of ratio spectrum, the third one is novel constant center spectrophotometric method (CC) and the fourth method is mean centering of ratio spectra (MCR). The calibration curve is linear over the concentration range of 4-20 and 10-45 µg/ml for CIN and DIM, respectively. These methods are tested by analyzing synthetic mixtures of the above drugs and they are applied to commercial pharmaceutical preparation of the subjected drugs. The validity of results was assessed by applying standard addition technique. The results obtained were found to agree statistically with those obtained by a reported method, showing no significant difference with respect to accuracy and precision.

Determination of sulphasalazine and its main metabolite sulphapyridine and 5-aminosalicylic acid in human plasma by liquid chromatography/tandem mass spectrometry and its application to a pharmacokinetic study.

A simple and sensitive liquid chromatography/positive-ion electrospray ionization mass spectrometry (LC-ESI-MS/MS) method has been developed for the simultaneous determination of sulphasalazine (SASP) and its main metabolite sulphapyridine (SP) and 5-aminosalicylic acid (5-ASA) with 100 µL of human plasma using dimenhydrinate as the internal standard (I.S.). The API-3000 LC-MS/MS was operated under the multiple reaction-monitoring mode (MRM) using the electrospray ionization technique. Protein precipitation process was used to extract SASP, SP, 5-ASA and I.S. from human plasma. The total run time was 9.0 min and the elution of SASP, SP and 5-ASA was at 4.8 min, 2.5 min and 2.0 min, respectively. The separation was achieved with a mobile phase consisting of 0.2% formic acid, 2 mM ammonium acetate in water (mobile phase A) and 0.2% formic acid, 2 mM ammonium acetate in methanol (mobile phase B) by using gradient elution on a XBP Phenyl column (100 mm × 2.1 mm, 5 µm). The developed method was validated in human plasma with a lower limit of quantitation of 10 ng/mL for SASP, SP and 5-ASA, respectively. A linear response function was established for the range of concentrations 10-10,000 ng/mL (r>0.99) for SASP and 10-1000 ng/mL (r>0.99) for SP and 5-ASA. The intra and inter-day precision values for SASP, SP and 5-ASA met the acceptance as per FDA guidelines. SASP, SP and 5-ASA were stable during stability studies, i.e., long term, auto-sampler and freeze/thaw cycles. The method was successfully applied for the evaluation of pharmacokinetics of SASP, SP and 5-ASA after single oral doses of 250 mg SASP to 10 healthy volunteers.

Direct standard-free quantitation of Tamiflu and other pharmaceutical tablets using clustering agents with electrospray ionization mass spectrometry.

Accurate and rapid quantitation is advantageous to identify counterfeit and substandard pharmaceutical drugs. A standard-free electrospray ionization mass spectrometry method is used to directly determine the dosage in the prescription and over-the-counter drugs Tamiflu, Sudafed, and Dramamine. A tablet of each drug was dissolved in aqueous solution, filtered, and introduced into solutions containing a known concentration of l-tryptophan, l-phenylalanine, or prednisone as a clustering agent. The active ingredient(s) incorporates statistically into large clusters of the clustering agent where effects of differential ionization/detection are substantially reduced. From the abundances of large clusters, the dosages of the active ingredients in each of the tablets were determined to typically better than 20% accuracy even when the ionization/detection efficiency of the individual components differed by over 100x. Although this unorthodox method for quantitation is not as accurate as using conventional standards, it has the advantages that it is fast, it can be applied to mixtures where the identities of the analytes are unknown, and it can be used when suitable standards may not be readily available, such as schedule I or II controlled substances or new designer drugs that have not previously been identified.

A simple HPLC-UV method for the determination of dimenhydrinate and related substances--dentification of an unknown impurity.

During the revision of the dimenhydrinate monograph of the European Pharmacopoeia a HPLC-UV method was developed. The procedure described allows a qualitative and quantitative determination of both dimenhydrinate compounds and of thirteen related substances. Furthermore a hitherto unknown impurity was identified and integrated into the purity check. Also 18 samples of dimenhydrinate have been tested. Thereby the relevant impurities of dimenhydrinate could be nominated and quantified.

Equipment for drug release testing of medicated chewing gums.

An apparatus was specially designed and constructed for release testing of medicated chewing gums. The adjustable instrumental settings such as temperature, chewing frequency, chewing time, volume of test medium, distance between the jaws and twisting angle increased the versatility of the apparatus. Selection of the test medium was also an important parameter. Each sample was kneaded mechanically in separate test chambers and the drug release was followed by sampling and HPLC analysis. Different gum formulations were tested and the obtained results demonstrated satisfactory release curves for a variety of formulations and active ingredients. The tested gum formulations comprised nicotine, meclizine, dimenhydrinate and xylitol. The apparatus proved to be suitable in product control of commercial batches but also a useful tool in the research and development of medicated gum formulations.

Ion mobility spectrometry and ion mobility spectrometry/mass spectrometric characterization of dimenhydrinate.

Positive and negative ion mobility spectra of dimenhydrinate are presented, and the calculated reduced mobility (K0) values for the most significant peaks are reported. Mass identification of the ionic species associated with the peaks in the ion mobility spectra was achieved by interfacing the ion mobility spectrometer to a mass spectrometer. The application of ion mobility spectrometry to the detection of dimenhydrinate and other drug residues on the hands of patients admitted to hospital with drug overdose is also discussed.

Spectrophotometric determination of dimenhydrinate with Reinecke salt.

A convenient spectrophotometric method was developed for the determination of dimenhydrinate in bulk drug and dosage forms and in 1:1 combinations with aspirin, acetaminophen, meprobamate, phenylephrine, and tolbutamide. The method consisted of reacting dimenhydrinate with reinecke salt in an acidic medium at 27 +/- 2 degrees. The purple precipitate was filtered and dissolved in acetone, and the maximum color absorption attained in 15 min was measured at 540 nm. Evidence is provided to establish the optimal experimental parameters. The stoichiometric balance of the precipitate was determined. Reasonably ideal adherence of the color absorption pattern to the Beer-Lambert law permitted microdetermination of dimenhydrinate in pure form, commercial formulations, laboratory-made combinations, and recovery experiments with good accuracy and repeatability. No interference was observed with any of the drugs or tablet adjuvants.