Journal of Pharmaceutical Analysis

Selection of appropriate analytical tools to determine the potency and bioactivity of antibiotics and antibiotic resistance$

Nishant A. Dafale n, Uttam P. Semwal, Rupak K. Rajput, G.N. Singh

2016, 6(4): 207-213.

Abstract(82) PDF(2)

Abstract:
Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms. Re-sistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics. In order to overcome the resistance problem and to safely use antibiotics, the correct measurement of potency and bioactivity of antibiotics is essential. Microbiological assay and high performance liquid chromatography (HPLC) method are used to quantify the potency of antibiotics. HPLC method is commonly used for the quantification of potency of antibiotics, but unable to determine the bioactivity; whereas microbiological assay estimates both potency and bioactivity of antibiotics. Additionally, bioassay is used to estimate the effective dose against antibiotic resistant microbes. Simultaneously, microbiological assay addresses the several parameters such as minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC), mutation prevention concentration (MPC) and critical concentration (Ccr) which are used to describe the potency in a more informative way. Microbiological assay is a simple, sensitive, precise and cost effective method which gives reproducible results similar to HPLC. However, the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results.

Determination of reactive oxygen generated from natural medicines and their antibacterial activity$

Noriko Tajima, Makiko Takasaki, Haruka Fukamachi, Takeshi Igarashi, Yoshijiro Nakajima, Hidetoshi Arakawa

2016, 6(4): 214-218.

Abstract(74) PDF(0)

Abstract:
Extracts of 16 natural medicine powders (Galla chinensis, Malloti cortex, Cassiae semen, Sophorae radix, Myricae cortex, Crataegi fructus, Gambir, Mume fructus, Geranii herba, Phellodendri cortex, Coptidis rhizoma, Swertiae herba, and Cinnamomi cortex) were assayed for reactive oxygen concentrations using the per-oxyoxalate chemiluminescent detection system. High luminescence intensity was observed in Galla chinensis, Geranii herba, Malloti cortex, Myricae cortex, and Cinnamomi cortex. Additional experiments identified the reactive oxygen species as hydrogen peroxide. Galla chinensis generated 2.4 ? 10 ? 4 mol/L hydrogen peroxide from a 1 mg/mL solution. In bacterial growth tests, Galla chinensis extract had antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacteroides thetaiotaomicron, Campylobacter sputorum biovar sputorum, Streptococcus salivarius thermophilus, Lactobacillus casei, and Bifidobacterium longum infantis. This antibacterial activity was de-creased by the addition of catalase. It revealed that hydrogen peroxide which Galla chinensis produced participated in antibacterial activity.

Determination of 6258-70, a new semi-synthetic taxane, in rat plasma and tissues:Application to the pharmacokinetics and tissue distribution study$

Simin Zhao, Yuanyuan Zhang, Ping Ju, Liqiang Gu, Rui Zhuang, Longshan Zhao, Xing Tang, Kaishun Bi, Xiaohui Chen n

2016, 6(4): 219-225.

Abstract(92) PDF(1)

Abstract:
Cancer is the leading cause of death all over the world. Among the chemotherapy drugs, taxanes play an important role in cancer treatment. 6258-70 is a new semi-synthetic taxane which has a broad spectrum of antitumor activity. A fast and reliable high performance liquid chromatography-tandem mass spec-trometry (HPLC–MS/MS) method was developed for quantification of 6258-70 in rat plasma and tissues in this paper. After extraction by liquid-liquid extraction method with methyl tert-butyl ether, the samples were separated on a Kinetex C18 column (50 mm ? 2.1 mm, 2.6 mm, Phenomenex, USA) within 3 min. The method was fully validated with the matrix effect between 87.7%and 99.5%and the recovery ranging from 80.3% to 90.1%. The intra- and inter-day precisions were less than 9.5% and the accuracy ranged from ? 3.8% to 6.5%. The reliable method was successfully applied to the pharmacokinetics and tissue distribution studies of 6258-70 after intravenous administration in rats. The pharmacokinetic results indicated that the pharmacokinetic behavior of 6258-70 in rats was in accordance with linear features within tested dosage of 1 to 4 mg/kg, and there was no significant difference between the two genders. The tissue distribution study showed that 6258-70 had an effective penetration, spread widely and rapidly and could cross blood-brain barrier. The results of pharmacokinetics and tissue distribution may provide a guide for future study.

Liquid chromatography-tandem mass spectrometry method for simultaneous determination of albendazole and albendazole sulfoxide in human plasma for bioequivalence studies$

Dhiraj M. Rathod, Keyur R. Patel, Hiren N. Mistri, Arvind G. Jangid, Pranav S. Shrivastav, Mallika Sanyal

2016, 6(4): 226-234.

Abstract(141) PDF(2)

Abstract:
An improved high performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) method has been developed for sensitive and rapid determination of albendazole (ABZ) and its active metabolite, albendazole sulfoxide (ABZSO), in the positive ionization mode. The method utilized solid phase ex-traction (SPE) for sample preparation of the analytes and their deuterated internal standards (ISs) from 100 mL human plasma. The chromatography was carried out on Hypurity C18 column using acetonitrile-2.0 mM ammonium acetate, pH 5.0 (80:20, v/v) as the mobile phase. The assay exhibited a linear re-sponse over the concentration range of 0.200–50.0 ng/mL for ABZ and 3.00–600 ng/mL for ABZSO. The recoveries of the analytes and ISs ranged from 86.03%–89.66% and 89.85%–98.94%, respectively. Matrix effect, expressed as IS-normalized matrix factors, ranged from 0.985 to 1.042 for the both analytes. The method was successfully applied for two separate studies in healthy subjects using single dose of 400 mg conventional tablets and 400 mg chewable ABZ tablets, respectively.

Graphene quantum dot modified glassy carbon electrode for the determination of doxorubicin hydrochloride in human plasma$

Nastaran Hashemzadeh, Mohammad Hasanzadeh, Nasrin Shadjou, Jamal Eivazi-Ziaei, Maryam Khoubnasabjafari, Abolghasem Jouyban

2016, 6(4): 235-241.

Abstract(102) PDF(0)

Abstract:
Low toxic graphene quantum dot (GQD) was synthesized by pyrolyzing citric acid in alkaline solution and characterized by ultraviolet–visible (UV–vis) spectroscopy, X-ray diffraction (XRD), atomic force micro-scopy (AFM), spectrofluorimetery and dynamic light scattering (DLS) techniques. GQD was used for electrode modification and electro-oxidation of doxorubicin (DOX) at low potential. A substantial de-crease in the overvoltage ( ? 0.56 V) of the DOX oxidation reaction (compared to ordinary electrodes) was observed using GQD as coating of glassy carbon electrode (GCE). Differential pulse voltammetry was used to evaluate the analytical performance of DOX in the presence of phosphate buffer solution (pH 4.0) and good limit of detection was obtained by the proposed sensor. Such ability of GQD to promote the DOX electron-transfer reaction suggests great promise for its application as an electrochemical sensor.

The thermal and storage stability of bovine haemoglobin by ultraviolet-visible and circular dichroism spectroscopies$

Ruchir Bhomia, Vivek Trivedi n, Nichola J. Coleman, John C. Mitchell

2016, 6(4): 242-248.

Abstract(93) PDF(0)

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The effects of temperature, pH and long-term storage on the secondary structure and conformation changes of bovine haemoglobin (bHb) were studied using circular dichroism (CD) and ultraviolet–visible (UV–vis) spectroscopies. Neural network software was used to deconvolute the CD data to obtain the fractional content of the five secondary structures. The storage stability of bHb solutions in pH 6, 7 and 8 buffers was significantly higher at 4 °C than at 23 °C for the first 3 days. A complete denaturation of bHb was observed after 40 days irrespective of storage temperature or pH. The bHb solutions were also ex-posed to heating and cooling cycles between 25 and 65 °C and structural changes were followed by UV–vis and CD spectroscopies. These experiments demonstrated that α-helix content of bHb decreased steadily with the increasing temperature above 35 °C at all pH values. The loss inα-helicity and gain in random coil conformations was pH-dependent and the greatest under alkaline conditions. Furthermore, there was minimal recovery of the secondary structure content upon cooling to 25 °C. The use of bHb as a model drug is very common and this study elucidates the significance of storage and processing con-ditions on its stability.

Quality evaluation of Huaijiao pill by chromatographic fingerprint and simultaneous determination of its major bioactive components$

Shuangqin Wang, Jingjing Zhang, Juan Liu, Guangsheng Qian, Chunmei Fu n

2016, 6(4): 249-255.

Abstract(122) PDF(0)

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For quality control purpose, an approach of combining chromatographic fingerprint of Huaijiao pill (HP) and simultaneous determination of its major bioactive components was developed using high performance liquid chromatography coupled with diode array detector (HPLC–DAD). For fingerprint analysis, 16 peaks were selected as the characteristic peaks to evaluate the similarities of different samples collected from different batches of three manufacturers. The similarities of 17 Huaijiao pill samples were beyond 0.966, indicating that samples from different batches and manufacturers were, to some extent, consistent. Ad-ditionally, simultaneous quantification of seven bioactive markers, namely sophoricoside, baicalin, nar-ingin, genistein, rutin, quercetin and 5-O-methylvisammioside, in HP was performed to interpret the quality consistency. The validation of the proposed approach was acceptable, with the accuracy of 90.2%–106.9%in recovery test. The intra-day and inter-day precisions of the method were evaluated and the RSD values were less than 2.81%. The results from the quantitative data showed that the contents of six marker compounds (except for 5-O-methylvisammioside) were quite consistent between batches produced by one manufacturer and significantly distinctive among different manufacturers. The proposed approach was expected to be developed as a powerful tool for the quality control of HP.

Effects of urea, metal ions and surfactants on the binding of baicalein with bovine serum albumin$

Atanu Singha Roy n, Amit Kumar Dinda, Nitin Kumar Pandey, Swagata Dasgupta

2016, 6(4): 256-267.

Abstract(100) PDF(1)

Abstract:
The interaction of baicalein with bovine serum albumin (BSA) was investigated with the help of spec-troscopic and molecular docking studies. The binding affinity of baicalein towards BSA was estimated to be in order of 105 M?1 from fluorescence quenching studies. NegativeΔH° (?5.6670.14 kJ/mol) and positive (ΔS°) ( t 79.96 7 0.65 J/mol K) indicate the presence of electrostatic interactions along with the hydrophobic forces that result in a positiveΔS°. The hydrophobic association of baicalein with BSA di-minishes in the presence of sodium dodecyl sulfate (SDS) due to probable hydrophobic association of baicalein with SDS, resulting in a negativeΔS° ( ? 40.65 7 0.87 J/mol K). Matrix-assisted laser desorption ionization/time of flight (MALDI–TOF) experiments indicate a 1:1 complexation between baicalein and BSA. The unfolding and refolding phenomena of BSA were investigated in the absence and presence of baicalein using steady-state and fluorescence lifetime measurements. It was observed that the presence of urea ruptured the non-covalent interaction between baicalein and BSA. The presence of metal ions (Ag t , Mg2 t , Ni2 t , Mn2 t , Co2 t and Zn2 t ) increased the binding affinity of ligand towards BSA. The changes in conformational aspects of BSA after ligand binding were also investigated using circular di-chroism (CD) and Fourier transform infrared (FT-IR) spectroscopic techniques. Site selectivity studies following molecular docking analyses indicated the binding of baicalein to site 1 (subdomain IIA) of BSA.&2016 Xi'an Jiaotong University. Production and hosting by Elsevier B.V. This is an open access article.

Validation of a liquid chromatographic method for the pharmaceutical quality control of products containing elacridar$

Emilia Sawicki, Michel J. Hillebrand, Hilde Rosing, Jan H.M. Schellens, Bastiaan Nuijen, Jos H. Beijnen

2016, 6(4): 268-275.

Abstract(126) PDF(1)

Abstract:
Many anticancer drugs have an impaired bioavailability and poor brain penetration because they are sub-strates to drug efflux pumps such as P-glycoprotein and Breast Cancer Resistance Protein. Elacridar is a strong inhibitor of these two drug efflux pumps and therefore has great potential to improve oral absorption and brain penetration of many anticancer drugs. Currently, a clinical formulation of elacridar is unavailable and therefore the pharmaceutical development of a drug product is highly warranted. This also necessitates the availability of an analytical method for its quality control. A reverse-phase high-performance liquid chro-matographic method with ultraviolet detection was developed for the pharmaceutical quality control of products containing elacridar as the active pharmaceutical ingredient. The analytical method was validated for linearity, accuracy, precision, selectivity, carry-over, stability of stock and reference solutions, stability of the final extract, stability-indicating capability and impurity testing. We found that elacridar is unstable in aqueous solutions that are exposed to light because a hydroxylation product of elacridar is formed. Therefore, sample solutions with elacridar must be protected from light.

SPE-UPLC-MS/MS assay for determination of letrozole in human plasma and its application to bioequivalence study in healthy postmenopausal Indian women$

Pravin G. Vanol, Puran Singhal, Priyanka A. Shah, Jaivik V. Shah, Pranav S. Shrivastav, Mallika Sanyal

2016, 6(4): 276-281.

Abstract(54) PDF(0)

Abstract:
A rapid and sensitive ultra performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method is described for determination of letrozole in human plasma. Following solid phase ex-traction (SPE) of letrozole and letrozole-d4 on Orochem DVB-LP cartridges, chromatography was per-formed on Acquity UPLC BEH C18 (50 mm ? 2.1 mm, 1.7 mm) column using methanol-0.1%formic acid in water (85:15, v/v) as the mobile phase. Detection was carried out on a triple quadrupole mass spec-trometer with an electrospray source, operated under positive ionization mode. Quantitation of letrozole and letrozole-d4 was done using multiple reaction monitoring (MRM) following the transitions at m/z 286.2-217.0 and m/z 290.2-221.0, respectively. The calibration plots were linear through the con-centration range of 0.10–100 ng/mL (r2Z0.9990) using 100 mL human plasma. The extraction recovery of letrozole ranged from 94.3% to 96.2% and the intra-batch and inter-batch precision was r 5.2%. The method was successfully applied to a bioequivalence study of letrozole after oral administration of 2.5 mg tablet formulation to 16 healthy postmenopausal Indian women. The assay reproducibility was also established through incurred sample reanalysis (ISR) of 74 subject samples.

Journal of Pharmaceutical Analysis

2016, 6(4): 282-283.

Abstract(96) PDF(1)

Abstract:

2016 Vol. 6, No. 4