Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
Molecules ; 26(5)2021 Mar 06.
Article in English | MEDLINE | ID: mdl-33800848

ABSTRACT

Despite its proven efficacy in diverse metabolic disorders, quercetin (QU) for clinical use is still limited because of its low bioavailability. D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) is approved as a safe pharmaceutical adjuvant with marked antioxidant and anti-inflammatory activities. In the current study, several QU-loaded self-nanoemulsifying drug delivery systems (SNEDDS) were investigated to improve QU bioavailability. A reversed phase high performance liquid chromatography (RP-HPLC) method was developed, for the first time, as a simple and sensitive technique for pharmacokinetic studies of QU in the presence of TPGS SNEDDS formula in rat plasma. The analyses were performed on a Xterra C18 column (4.6 × 100 mm, 5 µm) and UV detection at 280 nm. The analytes were separated by a gradient system of methanol and phosphate buffer of pH 3. The developed RP-HPLC method showed low limit of detection (LODs) of 7.65 and 22.09 ng/mL and LOQs of 23.19 and 66.96 ng/mL for QU and TPGS, respectively, which allowed their determination in real rat plasma samples. The method was linear over a wide range, (30-10,000) and (100-10,000) ng/mL for QU and TPGS, respectively. The selected SNEDDS formula, containing 50% w/w TPGS, 30% polyethylene glycol 200 (PEG 200), and 20% w/w pumpkin seed oil (PSO), showed a globule size of 320 nm and -28.6 mV zeta potential. Results of the pharmacokinetic studies showed 149.8% improvement in bioavailability of QU in SNEDDS relative to its suspension. The developed HPLC method proved to be simple and sensitive for QU and TPGS simultaneous determination in rat plasma after oral administration of the new SNEDDS formula.


Subject(s)
Adjuvants, Pharmaceutic/chemistry , Drug Compounding , Nanoparticles/administration & dosage , Polyethylene Glycols/chemistry , Quercetin/blood , Succinates/chemistry , alpha-Tocopherol/chemistry , Animals , Antioxidants/administration & dosage , Antioxidants/chemistry , Antioxidants/pharmacokinetics , Chromatography, High Pressure Liquid , Drug Delivery Systems , Male , Nanoparticles/chemistry , Quercetin/administration & dosage , Quercetin/chemistry , Quercetin/pharmacokinetics , Rats , Rats, Wistar , Surface-Active Agents , Tissue Distribution
2.
Molecules ; 24(5)2019 Feb 27.
Article in English | MEDLINE | ID: mdl-30818845

ABSTRACT

A high-performance liquid chromatography-diode array-mass spectrometric (LC-DAD-MS) method was developed and validated to investigate the related substances of olaparib (OLA) in bulk form. OLA was exposed to acid⁻base hydrolysis, boiling, oxidation with hydrogen peroxide, and UV light followed by LC-DAD-MS analysis. OLA and OLA-related substances were simultaneously and quantitatively monitored by DAD at 278 nm and triple quadrupole mass spectrometry (QQQ-MS). The investigated compounds were auto-scanned by an ion trap MS which applied positive and negative modes separately. The fragmentation pathway was confirmed by applying multi-steps fragmentation to identify the resulted cleaved ions and their parent ion. OLA was found to be sensitive to the alkaline hydrolysis and less sensitive to UV light. Two major hydrolytic degradation products, including the protonated molar ions m/z 299 and m/z 367, were identified. Three potential impurities were also characterized. The LC-MS limit of detection (LOD) and limit of quantification (LOQ) were 0.01 and 0.05 ng/µL, respectively. The quantitative results obtained by LC-DAD was comparable with that of LC-QQQ-MS. The proposed method shows good intra-day and inter-day precision with relative standard deviation (RSD) <2%.


Subject(s)
Antineoplastic Agents/analysis , Chromatography, Liquid/instrumentation , Chromatography, Liquid/methods , Phthalazines/analysis , Piperazines/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Gas Chromatography-Mass Spectrometry/methods
3.
J Pharm Biomed Anal ; 134: 195-202, 2017 Feb 05.
Article in English | MEDLINE | ID: mdl-27915197

ABSTRACT

A sensitive, selective and precise liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of propofol (PRO) in rat serum and hair has been developed. 3-Bromomethyl-propyphenazone was used as derivatization reagent forming propofol-methyl-propyphenazone compound. The derivatization reaction was optimized and validated for maximum MS sensitivity. The MS instrumental sensitivity reached to 10 attogram. The serum samples were extracted by using Chromabond C8 columns, while hair samples extracted with methanol. The tendency of volatility of PRO was minimized by adding triethylamine to the extract before the use of nitrogen gas for evaporation of solvent. The limit of quantitation (LLOQ) was 0.01pg/mL and the assay was linear to 10000pg/mL. The intra-and inter-day precision (RSD%) ranged from 0.33 to 3.44% while the accuracy (Er%, relative error) were -6.4 to 1.1%. The ionization suppression, due to reagent, was minimized by reacting the excess reagent with methanol, and eluting to waste before MS ionization source (2-4.5min). The method was successfully applied for detection and determination of PRO in rat serum and hair after 7-28days from administration of only one dose of propofol (10mg/kg).


Subject(s)
Antipyrine/analogs & derivatives , Hair/chemistry , Propofol/blood , Propofol/chemistry , Tandem Mass Spectrometry/methods , Animals , Antipyrine/chemistry , Chromatography, Liquid/methods , Hypnotics and Sedatives/blood , Hypnotics and Sedatives/chemistry , Male , Rats , Rats, Wistar
4.
J Fluoresc ; 22(1): 247-52, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21853256

ABSTRACT

A simple, selective and sensitive luminescence method has been developed for the assay of etodolac (I), moxepril HCl (II) and fexofenadine HCl (III) in bulk drug and pharmaceutical formulations. The method is based on the luminescence sensitization of europium (Eu(3+)) by complexation with the studied drugs. The fluorescence intensities of the products were measured at 667 nm for (I) and at 615 for (II) and (III) while exciting at 276 for all the studied drugs. The fluorescence intensity was directly proportional to the concentration over the range (20-280), (40-240) and (30-80) ng/ml with limits of detection (LOD) = 0.93, 0.92 and 0.95 µg/ml for drugs I, II and III respectively. Optimum conditions for the formation of the complex in methanol were carefully studied. The proposed method was successfully applied for the assay of the studied drugs in pharmaceutical formulations with excellent recovery.


Subject(s)
Etodolac/analysis , Europium/chemistry , Spectrometry, Fluorescence/methods , Terfenadine/analogs & derivatives , Tetrahydroisoquinolines/analysis , Buffers , Chemistry, Pharmaceutical , Etodolac/chemistry , Hydrogen-Ion Concentration , Reproducibility of Results , Terfenadine/analysis , Terfenadine/chemistry , Tetrahydroisoquinolines/chemistry , Tromethamine/chemistry
5.
Article in English | MEDLINE | ID: mdl-17223379

ABSTRACT

A simple, accurate, precise and sensitive colorimetric method for the determination of some skeletal muscle relaxant drugs, namely orphenadrine citrate (I), baclofen (II), antihistaminic drugs as acrivastine (III) and fexofenadine hydrochloride (IV) is described. This method is based on the formation of charge transfer complex with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) in non-aqueous medium. The orange color products were measured at 472, 465, 475 and 469 nm for drugs I, II, III and IV, respectively. The optimization of various experimental conditions was described. Beer's Law was obeyed in the range (2.5-17.5), (5-70), (2.5-25) and (10-50)microg/ml for drugs I, II, III and IV, respectively. The molar absorptivity (epsilon), sandell sensitivity, detection((LOD)) and quantitation limits((LOQ)) are calculated. The procedure was favorably applied for determination of certain pharmaceutical dosage forms containing the studied drugs. The obtained results were compared with the official and reported methods. There were no significant differences between proposed, reported and the official methods.


Subject(s)
4-Chloro-7-nitrobenzofurazan/chemistry , Histamine Antagonists/analysis , Neuromuscular Agents/analysis , Reproducibility of Results , Solvents , Spectrophotometry , Temperature , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...