Determination of mebudipine in human plasma by liquid chromatography�tandem mass spectrometry

In previous studies, mebudipine, a dihydropyridine calcium channel blocker, showed a considerable potential to be used in cardiovascular diseases. The aim of the current study was to develop a valid method using reversed-phase high performance liquid chromatography coupled with electrospray ionization mass spectrometry to assay mebudipine in the human plasma. Separation was achieved on a Zorbax Eclipse® C18 analytical column using a mobile phase consisted of methanol/water (90:10, v/v). The flow rate was 0.6 mL/min and carbamazepine was used as an internal standard (IS). This method involved the use of M +Na+ ions of mebudipine and IS at m/z 411 and 259, respectively with the selected ion monitoring (SIM) mode. There were no interfering peaks from endogenous components in blank plasma chromatograms. Standard curves were linear (r2>0.99) between 5 to 100 ng/mL. The mean extraction efficiency was about 84% and the limit of quantification for mebudipine was 5 ng/mL in plasma. The coefficient of variation and error at all of the intra-day and inter-day assessments were less than 11%. The results indicated that this method is a fast, accurate, sensitive, selective and reliable method for the determination of mebudipine in the human plasma. The assay method has been successfully used to estimate plasma concentration of mebudipine after the oral administration of 2.5 mg tablet in healthy adults. © 2015 by School of Pharmacy Shaheed Beheshti University of Medical Sciences and Health Services

Design and evaluation of oral nanoemulsion drug delivery system of mebudipine

A nanoemulsion drug delivery system was developed to increase the oral bioavailability of mebudipine as a calcium channel blocker with very low bioavailability profile. The impact of nano-formulation on the pharmacokinetic parameters of mebudipine in rats was investigated. Nanoemulsion formulations containing ethyl oleate, Tween 80, Span 80, polyethylene glycol 400, ethanol and deionized water were prepared using probe sonicator. The optimum formulation was evaluated for physicochemical properties, such as particle size, morphology and stability. The particle size of optimum formulation was 22.8 ± 4.0 nm. Based on the results of this study, the relative bioavailability of mebudipine nanoemulsion was enhanced by about 2.6-, 2.0- and 1.9-fold, respectively, compared with suspension, ethyl oleate solution and micellar solution. In conclusion, nanoemulsion is an interesting option for the delivery of poorly water soluble molecules, such as mebudipine. © 2015 Informa UK Limited, trading as Taylor & Francis Group

The role of Olea Europaea L. Fruit on A2780, A172 and HFFF2 proliferation

Olea europaea L. commonly known as olive has been traditionally used for the prevention and treatment of many diseases since ancient times. Olive has been reported to possess a broad spectrum of pharmacological properties. In the present study, we investigated the activity of aqueous extract of Olea europaea L. fruit at various concentrations on A2780, A172, and HFFF2 cell lines proliferation by MTT assay. Aqueous extract of olive significantly increased cell proliferation in a dose dependent manner in the cell lines. It has been previously reported that olive has chemoproventive and anti-tumor effects. These disagreements can be explained by differences in cell line properties, type of olive and different solvents in the extracts. However, further investigation is needed to clarify the exact role of olive in cell proliferation and cancer. In this study fruit extract of Olea europaea L. showed more activatory effects on A2780 cell line in comparison with A172 and HFFF2. These differences in the activatory effects may be related to the activation of different signaling pathways in different cell lines. © 2016, Iranian Association of Pharmaceutical Scientists. All rights reserved

Improved HPLC method for determination of four PPis, omeprazole, pantoprazole, lansoprazole and rabeprazole in human plasma

PURPOSE: To develop a simple and rapid HPLC method for measuring of four proton-pump inhibitors (PPIs), omeprazole (OPZ), pantoprazole (PPZ), lansoprazole (LPZ) and rabeprazole (RPZ) concentrations in human plasma. METHODS: Following a single step liquid-liquid extraction analytes along with an internal standard (IS) were separated using an isocratic mobile phase of phosphate buffer (10 mM)/acetonitrile (53/47, v/v adjusted pH to 7.3 with triethylamine) at flow rate of 1 mL/min on reverse phase TRACER EXCEL 120 ODS-A column at room temperature. RESULTS: Total analytical run time for selected PPIs was 10 min. The assays exhibited good linearity (r2>0.99) over the studied range of 20 to 2500 ng/mL for OPZ, 20 to 4000 ng/mL for PPZ, 20 to 3000 ng/mL for LPZ and 20 to 1500 ng/mL for RPZ. The recovery of method was equal or greater than 80 and lower limit of quantification (LLOQ) was 20 ng/mL for four PPIs. Coefficient of variation and error at all of the intra-day and inter-day assessment were less than 9.2 for all compounds. CONCLUSIONS: The results indicated that this method is a simple, rapid, precise and accurate assay for determination of four PPIs concentrations in human plasma. This validated method is sensitive and reproducible enough to be used in pharmacokinetic studies and also is time- and cost-benefit when selected PPIs are desired to be analyzed

Design and evaluation of a novel nanodrug delivery system for reducing the side effects of clomiphene citrate on endometrium

Background: Stimulation of ovulation with clomiphene citrate can cause side effects on endometrial receptivity. Formulation with nano-size may be an alternative therapy for women with ovulatory disorders. In this study, we investigated sustained-release clomiphene citrate by using Phosal-based formulation (PBF) and evaluate its decreased side effect on the endometrial receptivity. Methods: In the in-vitro study, CC loaded PBF was analyzed using Zetasizer, Fourier-transform infrared spectroscopy (FTIR), and Transmission electron microscopy (TEM). In the in-vivo study, 24 female mice were randomly divided into three groups: CC (5 mg/kg), CC/PBF (5 mg/kg) and SS (1 ml) daily administered and injected with 5 IU HCG and mated after two days. At day 4.5, pregnant mice were euthanized and endometrial tissue was extracted for quantitative polymerase chain reaction (Q-PCR) analysis. Results: The optimized PBF contained Phosal 50PG/glycerol in a 2:8 ratios (w/w) and the particle size of optimum formulation was 67 ± 0.30551 nm and the release of CC from CC-containing PBF was slightly faster in the first 24 h; wherein, 29 of CC was released, and 76 of CC was released up to 120 h. The mRNA levels of leukemia inhibitory factor (LIF), leukemia inhibitory factor receptor alpha (LIFR), HOXA10, Heparin-binding epidermal growth factor (HB-EGF), and epidermal growth factor (EGF) were significantly upregulated and MUC1 and PGR mRNA levels were significantly downregulated in the CC-containing PBF-treated animals compared with only CC group (P < 0.05). Conclusion: Sustained release formulation of clomiphene citrate increased its targeting efficiency and improved the impact of the CC on implantation. Figure not available: see fulltext. © 2019, Springer Nature Switzerland AG

Assessment of the antinociceptive effects of pregabalin alone or in combination with morphine during acetic acid-induced writhing in mice

Visceral pain currently represents one of the most important pain treatment challenges in clinical practice, and investigators across the world are continuously designing and conducting numerous studies in search of new analgesics and new combination therapies. The current study assessed the analgesic effects of saline, pregabalin (2, 5, 17, 50, 100, and 200 mg/kg, i.p.) and morphine (0.25, 0.5, 1, 3 and 5 mg/kg) alone or in combination on acetic-acid induced abdominal contractions in mice. The number of writhes and the inhibitory effects (as percentages, E)were calculated as antinociception indexes. These indexes indicated that both pregabalin (Prg) and morphine (Mrp) produced dose-dependent antinociception. Pregabalin at 5 mg/kg (E = 32.5 ± 4.0) or 2 mg/kg (E = 20.8 ± 4.5) and morphine at 0.25 mg/kg (E = 20.2 ± 7.8) and 0.5 mg/kg (E = 43.6 ± 4.5) exhibited antinociceptive effects, and the combination of pregabalin and morphine produced significantly greater antinociceptive effects (E = 62.4 ± 5.8 for Prg5 + Mrp0.25; E = 71.7 ± 4.8 for Prg5 + Mrp0.5; and E = 54.1 ± 4.0 for Prg2 + Mrp0.25), although this enhancement was not observed when morphine was combined with 17 mg/kg pregabalin. Pre-treatment with 2 mg/kg (i.p.) naloxone did not affect increased analgesia when combined with these drugs. A dose-response curve was established for pregabalin at a fixed morphine dose and revealed that, at lowdoses, pregabalin dose-dependently enhanced the antinociceptive effects,while the opposite was true at high doses (17 and 25 mg/kg). In conclusion, pregabalin can produce levels of antinociception that are similar to those of morphine in acetic acid-induced viscero-somatic pain. The enhancement of antinociception produced by the co-administration of morphine and pregabalin is termed a supra-additive interaction and occurred at lowdoses but not at high doses. These findings militate for increased attention and caution in clinical settings. © 2013 Elsevier Inc. All rights reserved

Use of artificial neural networks for analysis of the factors affecting particle size in mebudipine nanoemulsion

In this study, a nanoemulsion containing mebudipine composed of ethyl oleate (oil phase), Tween 80 (T80), Span 80 (S80) (surfactants), polyethylene glycol 400, ethanol (cosurfactants), and deionized water was prepared with the aim of improving its bioavailability for an effective antihypertensive therapy. Particle size of the formulation was measured by dynamic light scattering. Then, artificial neural networks were used in identifying factors that influence the particle size of the nanoemulsion. Three variables, namely, amount of surfactant system (T80 + S80), amount of polyethylene glycol, and amount of ethanol as cosurfactants, were considered as input values and the particle size was used as output. The developed model showed that all the three inputs had some degrees of effect on particles size: increasing the value of each input decreased the size. Furthermore, amount of surfactant was found to be the dominant factor in controlling the final particle size of nanoemulsion. Communicated by Ramaswamy H. Sarma. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group

Extraction of crocin from saffron (Crocus sativus) using molecularly imprinted polymer solid-phase extraction

A new molecularly imprinted polymer for extraction of crocin from saffron stigmas was prepared using gentiobiose (a glycoside moiety in crocin structure) as a template. Crocin binding to gentiobiose imprinted polymer (Gent-MIP) was studied in comparison with a blank nonimprinted polymer in aqueous media. Affinity of the Gent-MIP for the crocin was more than the nonimprinted polymer at all concentrations. In Scatchard analysis, the number of binding sites in each gram of polymer (maximum binding sites) and dissociation constant of crocin to binding sites were 18.4 μmol/g polymer and 11.2 μM, respectively. The Gent-MIP was then used as the sorbent in an SPE method for isolation and purification of crocin from methanolic extract of saffron stigmas. The recovery of crocin, safranal and picrocrocin was determined in washing and elution steps. The Gent-MIP had significantly higher affinity for crocin than other compounds and enabled selective extraction of crocin with a high recovery (84) from a complex mixture. The results demonstrated the possibility of using a part of a big molecule in preparing a molecularly imprinted polymer with a good selectivity for the main structure. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA

The Role of NMDARs Ligands on Antinociceptive Effects of Pregabalin in the Tail Flick Test

BACKGROUND: Pregabalin as a new anticonvulsant has been used in different pain treatments. OBJECTIVES: The aim of this study was to investigate the role of N-methyl-D-aspartate (NMDA) ligands in antinociceptive effect of pregabalin in mice using tail flick. MATERIALS AND METHODS: NMDA (15 and 30 mg/kg) as an agonist or MK801 (0.02 and 0.05 mg/kg) as an antagonist were injected intraperitoneally either alone or 15 minutes before antinociceptive dose of pregabalin (100 mg/kg). Then the latency times and %MPE were measured in the tail flick assay during 75 minutes. RESULTS: NMDA and MK801 had no effects alone. NMDA pretreatment significantly decreased the latency times of pregabalin till 75th minutes. In NMDA pretreated groups, %MPE30 unlike %MPE75 decreased significantly compared to those of pregabalin. MK801 delayed the latency times in pretreated groups, but %MPE30 and %MPE75 did not change significantly compared to pregabalin alone. CONCLUSIONS: Our findings support the role of NMDARs in pregabalin antinociception, because the NMDAR agonist, unlike the antagonist, decreased the antinociceptive effect of pregabalin, even if tail flick is not an adequate pain assessment method in this regard