Journal of Pharmaceutical Analysis

Analytical methods for determination of terbinafine hydrochloride in pharmaceuticals and biological materials$

Basavaiah Kanakapura n, Vamsi Krishna Penmatsa

2016, 6(3): 137-149.

Abstract(111) PDF(0)

Abstract:
Terbinafine is a new powerful antifungal agent indicated for both oral and topical treatment of myco-sessince. It is highly effective in the treatment of determatomycoses. The chemical and pharmaceutical analysis of the drug requires effective analytical methods for quality control and pharmacodynamic and pharmacokinetic studies. Ever since it was introduced as an effective antifungal agent, many methods have been developed and validated for its assay in pharmaceuticals and biological materials. This article reviews the various methods reported during the last 25 years.

Ion-pairing HPLC methods to determine EDTA and DTPA in small molecule and biological pharmaceutical formulations$

George Wang, Frank P. Tomasella

2016, 6(3): 150-156.

Abstract(135) PDF(2)

Abstract:
Ion-pairing high-performance liquid chromatography–ultraviolet (HPLC–UV) methods were developed to determine two commonly used chelating agents, ethylenediaminetetraacetic acid (EDTA) in Abilifys (a small molecule drug with aripiprazole as the active pharmaceutical ingredient) oral solution and die-thylenetriaminepentaacetic acid (DTPA) in Yervoys (a monoclonal antibody drug with ipilimumab as the active pharmaceutical ingredient) intravenous formulation. Since the analytes, EDTA and DTPA, do not contain chromophores, transition metal ions (Cu2 t , Fe3 t ) which generate highly stable metallocom-plexes with the chelating agents were added into the sample preparation to enhance UV detection. The use of metallocomplexes with ion-pairing chromatography provides the ability to achieve the desired sensitivity and selectivity in the development of the method. Specifically, the sample preparation in-volving metallocomplex formation allowed sensitive UV detection. Copper was utilized for the de-termination of EDTA and iron was utilized for the determination of DTPA. In the case of EDTA, a gradient mobile phase separated the components of the formulation from the analyte. In the method for DTPA, the active drug substance, ipilimumab, was eluted in the void. In addition, the optimization of the concentration of the ion-pairing reagent was discussed as a means of enhancing the retention of the aminopolycarboxylic acids (APCAs) including EDTA and DTPA and the specificity of the method. The analytical method development was designed based on the chromatographic properties of the analytes, the nature of the sample matrix and the intended purpose of the method. Validation data were presented for the two methods. Finally, both methods were successfully utilized in determining the fate of the chelates.

A novel surface molecularly imprinted polymer as the solid-phase extraction adsorbent for the selective determination of ampicillin sodium in milk and blood samples$

Ningli Wu, Zhimin Luo, Yanhui Ge, Pengqi Guo, Kangli Du, Weili Tang, Wei Du, Aiguo Zeng, Chun Chang, Qiang Fu

2016, 6(3): 157-164.

Abstract(118) PDF(1)

Abstract:
Surface molecularly imprinted polymers (SMIPs) for selective adsorption of ampicillin sodium were synthesized using surface molecular imprinting technique with silica gel as a support. The physical and morphological characteristics of the polymers were investigated by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), elemental analysis and nitrogen adsorption–desorption test. The obtained results showed that the SMIPs displayed great adsorption capacity (13.5μg/mg), high recognition ability (the imprinted factor is 3.2) and good binding kinetics for ampicillin sodium. Finally, as solid phase extraction adsorbents, the SMIPs coupled with HPLC method were validated and applied for the enrichment, purification and determination of ampicillin sodium in real milk and blood samples. The averages of spiked accuracy ranged from 92.1%to 107.6%. The relative standard deviations of intra-and inter-day precisions were less than 4.6%. This study provides a new and promising method for enriching, extracting and determining ampicillin sodium in complex biological samples.

Molecular dynamics of amorphous pharmaceutical fenofibrate studied by broadband dielectric spectroscopy$

U. Sailaja, M. Shahin Thayyil, N.S. Krishna Kumar, G. Govindaraj

2016, 6(3): 165-170.

Abstract(114) PDF(0)

Abstract:
Fenofibrate is mainly used to reduce cholesterol level in patients at risk of cardiovascular disease. Thermal transition study with the help of differential scanning calorimetry (DSC) shows that the aforesaid active pharmaceutical ingredient (API) is a good glass former. Based on our DSC study, the molecular dynamics of this API has been carried out by broadband dielectric spectroscopy (BDS) covering wide temperature and frequency ranges. Dielectric measurements of amorphous fenofibrate were per-formed after its vitrification by fast cooling from a few degrees above the melting point (Tm ? 354.11 K) to deep glassy state. The sample does not show any crystallization tendency during cooling and reaches the glassy state. The temperature dependence of the structural relaxation has been fitted by single Vogel–Fulcher–Tamman (VFT) equation. From VFT fit, glass transition temperature (Tg) was estimated as 250.56 K and fragility (m) was determined as 94.02. This drug is classified as a fragile glass former. Deviations of experimental data from Kohlrausch–Williams–Watts (KWW) fits on high-frequency flank of α-peak indicate the presence of an excess wing in fenofibrate. Based on Ngai's coupling model, we identified the excess wing as true Johari–Goldstein (JG) process. Below the glass transition temperature one can clearly see a secondary relaxation (γ) with an activation energy of 32.67 kJ/mol.

On-line near-infrared spectroscopy optimizing and monitoring biotransformation process ofγ-aminobutyric acid$

Guoyu Ding, Yuanyuan Hou, Jiamin Peng, Yunbing Shen, Min Jiang, Gang Bai

2016, 6(3): 171-178.

Abstract(72) PDF(0)

Abstract:
Near-infrared spectroscopy (NIRS) with its fast and nondestructive advantages can be qualified for the real-time quantitative analysis. This paper demonstrates that NIRS combined with partial least squares (PLS) regression can be used as a rapid analytical method to simultaneously quantify L-glutamic acid (L-Glu) andγ-aminobutyric acid (GABA) in a biotransformation process and to guide the optimization of production conditions when the merits of NIRS are combined with response surface methodology. The high performance liquid chromatography (HPLC) reference analysis was performed by the o-phthaldialdehyde pre-column derivatization. NIRS measurements of two batches of 141 samples were firstly analyzed by PLS with several spectral pre-processing methods. Compared with those of the HPLC reference analysis, the resulting determination coefficients (R2), root mean square error of prediction (RMSEP) and residual predictive deviation (RPD) of the external validation for the L-Glu concentration were 99.5%, 1.62 g/L, and 11.3, respectively. For the GABA concentration, R2, RMSEP, and RPD were 99.8%, 4.00 g/L, and 16.4, re-spectively. This NIRS model was then used to optimize the biotransformation process through a Box-Behnken experimental design. Under the optimal conditions without pH adjustment, 200 g/L L-Glu could be catalyzed by 7148 U/L glutamate decarboxylase (GAD) to GABA, reaching 99%conversion at the fifth hour. NIRS analysis provided timely information on the conversion from L-Glu to GABA. The results suggest that the NIRS model can not only be used for the routine profiling of enzymatic conversion, providing a simple and effective method of monitoring the biotransformation process of GABA, but also be considered to be an optimal tool to guide the optimization of production conditions.

Monitoring real time polymorphic transformation of sulfanilamide by diffuse reflectance visible spectroscopy$

Tracy O. Ehiwe, Bruce D. Alexander, John C. Mitchell, Martin J. Snowden, Laura J. Waters

2016, 6(3): 179-183.

Abstract(76) PDF(0)

Abstract:
This study investigated the development of a novel approach to surface characterization of drug poly-morphism and the extension of the capabilities of this method to perform ‘real time’ in situ measure-ments. This was achieved using diffuse reflectance visible (DRV) spectroscopy and dye deposition, using the pH sensitive dye, thymol blue (TB). Two polymorphs, SFN-β and SFN-γ, of the drug substance sul-fanilamide (SFN) were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model (R2 ? 0.992), giving a rate constant of 2.43 ? 10 ? 2 s ? 1.

Development of an LC-MS/MS method for the quantitation of deoxyglycychloxazol in rat plasma and its application in pharmacokinetic study$

Rongshan Li, Ruixue Ran, Quansheng Li, Yurong Huang, Yuan Gu, Duanyun Si

2016, 6(3): 184-189.

Abstract(143) PDF(0)

Abstract:
Deoxyglycychloxazol (TY501) is a glycyrrhetinic acid derivative which exhibits high anti-inflammatory activity and reduced pseudoaldosteronism compared to glycyrrhetinic acid. In this study, a sensitive and rapid liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was established for the quantitation of TY501 in rat plasma. Plasma samples were treated by precipitating protein with methanol and supernatants were separated by a Symmetry C8 column with the mobile phase consisting of me-thanol and 10 mM ammonium formate (containing 0.1%of formic acid) (90:10, v/v). The selected reaction monitoring (SRM) transitions were performed at m/z 647.4-191.2 for TY501 and m/z 473.3-143.3 for astragaloside aglycone (IS) in the positive ion mode with atmospheric pressure chemical ionization (APCI) source. Calibration curve was linear over the concentration range of 5–5000 ng/mL. The lower limit of quantification was 5 ng/mL. The mean recovery was over 88%. The intra-and inter-day precisions were lower than 6.0% and 12.8%, respectively, and the accuracy was within 71.3%. TY501 was stable under usual storage conditions and handling procedure. The validated method has been successfully applied to a pharmacokinetic study after oral administration of TY501 to rats at a dosage of 10 mg/kg.

Development and validation of a high throughput UPLC-MS/MS method for simultaneous quantification of esomeprazole, rabeprazole and levosulpiride in human plasma$

Raja Haranadha Babu Chunduri a, n, Gowri Sankar Dannana b

2016, 6(3): 190-198.

Abstract(125) PDF(16)

Abstract:
A high throughput ultra pressure liquid chromatography–mass spectrometry (UPLC–MS/MS) method with good sensitivity and selectivity has been developed and validated for simultaneous quantification of esomeprazole, rabeprazole and levosulpiride in human plasma using lansoprazole as internal standard (IS). The extraction method based on liquid–liquid extraction technique was used to extract the analytes and IS from of 50 mL of human plasma using methyl tert-butyl ether:ethyl acetate (80:20, v/v), which offers a high recovery. Chromatographic separation of analytes and IS was achieved on a Hypersil gold C18 column using gradient mobile phase consisting of 2 mM ammonium formate/acetonitrile. The flow rate was set at 0.5 mL/min to elute all the analytes and IS within 1.00 min runtime. Detection of target compounds was performed on a triple quadruple mass spectrometer by multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI). Method validation results demonstrated that the developed method has good precision and accuracy over the concentration ranges of 0.1–2000 ng/mL for each analyte. Stability of compounds was established in a battery of stability studies, i.e., bench top, autosampler, dry extract and long-term storage stability as well as freeze-thaw cycles. The validated method has been successfully applied to analyze human plasma samples for application in pharmaco-kinetic studies.

Simultaneous determination of doxorubicin and its dipeptide prodrug in mice plasma by HPLC with fluorescence detection$

Jing Han, Jue Zhang, Haiyan Zhao, Yan Li, Zilin Chen

2016, 6(3): 199-202.

Abstract(93) PDF(0)

Abstract:
A simple and sensitive high performance liquid chromatography with fluorescence detection (HPLC–FD) has been developed for simultaneous quantification of doxorubicin (DOX) and its dipeptide conjugate prodrug (PDOX) in mice plasma. The chromatographic separation was carried out on an Amethyst C18–H column with gradient mobile phase of 0.1%formic acid and 0.1%formic acid in acetonitrile at a flow rate of 1.0 mL/min. The excitation and emission wavelengths were set at 490 and 550 nm, respectively. The method was comprehensively validated. The limits of detection were low up to 5.0 ng/mL for DOX and 25.0 ng/mL for PDOX. And the limits of quantification were low up to 12.5 ng/mL for DOX and 50 ng/mL for PDOX, which were lower than those for most of the current methods. The calibration curves showed good linearity (R2 4 0.999) over the concentration ranges. The extraction recoveries ranged from 84.0%to 88.2% for DOX and from 85.4% to 89.2% for PDOX. Satisfactory intra-day and inter-day precisions were achieved with RSDs less than 9.1%. The results show that the developed HPLC–FD method is accurate, reliable and will be helpful for preclinical pharmacokinetic study of DOX and PDOX.

Preliminary assessment of two non-destructive instrumental techniques for quality evaluation of Lobelia chinensis Lour.$

Hong-Peng Chen, Wen-Jia Pan, Nan Tang, Yuan Zhang, Mei-Ling Yu, Xing-Da Wu

2016, 6(3): 203-206.

Abstract(63) PDF(0)

Abstract:
Two non-destructive instrumental methods, infrared spectroscopy (IR) and X-ray diffraction (XRD), were studied for quality evaluation of Lobelia chinensis Lour. (L. chinensis). We obtained the IR spectra and XRD patterns of L. chinensis collected from different sources. The similarity of samples was analyzed by cal-culating the cosine coefficient. The cosine values were in the range of 0.83–0.90, indicating that the main components of L. chinensis samples are similar. Sample L1 and L6 showed a slightly lower similarity than that of L2, L3, L4, L5 detected by the two methods, which revealed that IR and XRD methods exhibited analogous detection ability for quality evaluation of L. chinensis. The two methods could be highly re-commended as simple and rapid detection means for quality evaluation of L. chinensis.

2016 Vol. 6, No. 3