Highly sensitive and selective determination of methylergometrine maleate using carbon nanofibers/silver nanoparticles composite modified carbon paste electrode.

A highly sensitive and selective voltammetric method for determination of Methylergometrine maleate (MM) in pharmaceutical formulations, urine and blood serum samples has been developed based on enhanced electrochemical response of MM at carbon nanofibers and silver nanoparticles modified carbon paste electrode (CNF-AgNP-CPE). The electrode material was characterized by various techniques viz., X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The electrocatalytic response of MM at CNF-AgNP-CPE was studied by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Under optimized conditions, the proposed sensor exhibits excellent electrochemical response towards MM. The DPV study shows greatly enhanced electrochemical signal for MM at CNF-AgNP-CPE lending high sensitivity to the proposed sensor for MM detection. The peak (Ip) current for MM is found to be rectilinear in the range 4.0×10(-8)-2.0×10(-5)M with a detection limit of 7.1×10(-9)M using DPV. The feasibility of the proposed sensor in analytical applications was investigated by conducting experiments on commercial pharmaceutical formulations, human urine and blood serum samples, which yielded satisfactory recoveries of MM. The proposed electrochemical sensor offers high sensitivity, selectivity, reproducibility and practical utility. We recommend it as an authentic and productive electrochemical sensor for successful determination of MM.

Impact of temperature exposure on stability of drugs in a real-world out-of-hospital setting.

STUDY OBJECTIVE: The aim of this study is to determine the content of 5 important emergency medical services (EMS) drugs after being stored at the recommended refrigerated temperature, room temperature, or in an emergency physician transport vehicle operating under real-world working conditions. METHODS: Adrenaline hydrochloride, cisatracurium besylate, lorazepam, methylergonovine maleate, and succinylcholine chloride were stored for 1 year under the 3 conditions. For each storage condition, samples of the drugs were taken after 1, 2, 3, and 4 weeks and after 2, 4, 6, 8, 10, and 12 months. For adrenaline hydrochloride, however, the samples were taken after 1, 2, 4, 6, 8, 10, and 12 months. The samples were analyzed with a validated high-performance liquid chromatography assay. A drug was considered stable if its content was above 90%. RESULTS: Adrenaline hydrochloride and methylergonovine maleate remained stable for 1 year at room temperature and in the emergency physician transport vehicle. At room temperature and in the emergency physician transport vehicle, lorazepam became unstable within 4 weeks. Succinylcholine chloride was stable for 2 months at room temperature and for 1 month in the emergency physician transport vehicle. Cisatracurium besylate became unstable within 4 months at room temperature. However, it remained stable for 4 months in the emergency physician transport vehicle. CONCLUSION: When stored at room temperature or in the emergency physician transport vehicle, lorazepam became unstable within weeks, whereas succinylcholine chloride and cisatracurium besylate became unstable within months. Adrenaline hydrochloride and methylergonovine maleate remained stable for several months, even under room temperature and emergency physician transport vehicle conditions. Thus, real-world EMS working conditions pose challenges for maintaining optimal efficacy of these important EMS drugs.

Monitoring of methylergometrine in human breast milk by solid-phase extraction and high-performance liquid chromatography with fluorimetric detection.

A high-performance liquid chromatographic assay has been developed for the detection and quantification of the conventional postnatal uterotonic drug, methylergometrine, in human breast milk using a C-18 reversed-phase column by isocratic elution. The analytical method consisted of sample clean-up by solid-phase extraction, and the fluorescence detection required only 8.5 min per sample for separation and quantitation. This assay gave intra- and inter-assay coefficients of variation of less than 7.9% and 7.7%, respectively, and the detection limit was approximately 50 pg/ml. This method was applied for drug level monitoring in the breast milk of patients given methylergometrine.

Determination of methylergometrine and dihydroergotoxine in biological fluids.

New hapten-carrier conjugates were prepared from 9,10-dihydro-N-[1-(hydroxymethyl)propyl]-6-methylergoline-8-carboxamide 1-hemisuccinate (dihydromethylergometrine hemisuccinate) by coupling with bovine serum albumin employing the mixed anhydride technique. The specificity of anti-dihydromethylergometrine antiserum elicited in the rabbits by immunization with this antigen was tested by cross-reaction studies with methylergometrine, dihydroergotoxine, dihydroergocristine and dihydroergotamine employing [9,10-3H]-dihydromethylergometrine and [9,10-3H]-dihydroergocryptine in the radioimmunoassay procedure. These cross reactivities were observed 100% for methylergometrine, 48.3% for dihydroergotamine, 16.6% for dihydroergotoxine and 6.6% for dihydroergocristine using labeled dihydromethylergometrine. When labeled dihydroergocriptine was the results were 18.3%, 112.1%, 100% and 63.8%, respectively. Methylergometrine concentrations in the postpartal plasma and milk at 2 hr after oral administration of methylergometrine maleate (0.75 mg) to woman were 5.1 ng/ml and 1.3 ng/ml, respectively. Dihydroergotoxine concentrations in the rabbit sera after oral administration of dihydroergotoxine methanesulfonate (4 mg) were studied. The assay was satisfactory to permit the measurement of ergot alkaloid levels in the biological fluids.