| 1. |
- Prasanta, Paul, et al.
(författare)
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CE-C4D method development and validation for the assay of ciprofloxacin
- 2016
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Ingår i: Journal of Pharmaceutical and Biomedical Analysis. - : Elsevier BV. - 0731-7085 .- 1873-264X. ; 129, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- A capillary electrophoresis method with capacitively coupled contactless conductivity detection (CE-C(4)D) has been developed, optimized and validated for the determination of ciprofloxacin. Ciprofloxacin is a member of the fluoroquinolone antibiotics with a broad spectrum bactericidal activity and recommended for complicated respiratory infections, sexually transmitted diseases, tuberculosis, bacterial diarrhea etc. Method development was conducted with major focus on the quality by design (QbD) approach. During method development, multiple buffers were tried at different ionic strength. However, the optimized method finally involved a very simple background electrolyte, monosodium citrate at a concentration of 10mM without pH adjustment. The optimized CE-C(4)D method involved an uncoated fused silica capillary (59/39cm, 50μm i.d.) and hydrodynamic sample injection at a pressure of 0.5 p.s.i. for 5s. The actual separation was conducted for 10min at normal polarity with a voltage of 20kV corresponding to 5.9μA current. LiCl (1mg/mL) was used as an internal standard. The optimized method is robust and accurate (recovery >98%) which rendered the ciprofloxacin peak within five minutes with good linearity (R(2)>0.999) in the concentration range of 0.0126-0.8mg/mL. The repeatability is expressed by percentage relative standard deviation (%RSD) of the relative peak areas (RPA) and it showed good repeatability both intra-day (<3%) and inter-day (3.1%). This method, proven to be free of matrix interference, showed that the estimated percent content of ciprofloxacin (102%) was within the official requirements. Moreover, due to its ease of use and robustness, the method should also be applicable in less well controlled laboratory environments.
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| 2. |
- van Tricht, Ewoud, et al.
(författare)
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Fast, selective and quantitative protein profiling of adenovirus-vector based vaccines by ultra-performance liquid chromatography
- 2018
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Ingår i: Journal of Chromatography A. - : ELSEVIER SCIENCE BV. - 0021-9673 .- 1873-3778. ; 1581-1582, s. 25-32
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Tidskriftsartikel (refereegranskat)abstract
- A method for the quantitative determination of the protein composition of adenovirus-vector based vaccines was developed. The final method used RP-UPLC with UV absorbance detection, a C4 column (300 angstrom, 1.7 mu m, 2.1 x 150 mm), and a water- acetonitrile (ACN) gradient containing trifluoroacetic acid (TFA) as ion-pairing agent. The chromatographic resolution between the various adenovirus proteins was optimized by studying the effect of the TFA concentration and the column temperature, applying a full factorial design of experiments. A reproducible baseline separation of all relevant adenovirus proteins could be achieved within 17 min run time. Samples containing adenovirus particles could be directly injected into the UPLC system without sample pretreatment. The viruses reproducibly dissociate into proteins in the UPLC system upon contact with the mobile phase containing ACN. The new RP-UPLC method was successfully validated for protein profiling and relative quantification of proteins in vaccine products based on adenovirus vector types 26 and 35. The intermediate precision of the relative peak areas of all proteins was between 1% and 14% RSD, except for the peak assigned to protein V (26% RSD). The method proved to be stability indicating with respect to thermal and oxidation stress of the adenovirus-vector based vaccine and was successfully implemented for the characterization of adenovirus-based products.
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| 3. |
- Paul, Prasanta, et al.
(författare)
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A simple, low-cost and robust capillary zone electrophoresis method with capacitively coupled contactless conductivity detection for the routine determination of four selected penicillins in money-constrained laboratories.
- 2018
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Ingår i: Electrophoresis. - : Wiley. - 0173-0835 .- 1522-2683. ; 39:20, s. 2521-2529
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Tidskriftsartikel (refereegranskat)abstract
- A simple and robust capillary zone electrophoresis method was developed and validated for the determination of amoxicillin and clavulanate, ampicillin, phenoxymethyl penicillin (Pen V) as well as flucloxacillin. Capacitively coupled contactless conductivity detection was employed as detection mode that makes CE a simple and economic tool for money-constrained laboratories. The developed method is straightforward and user-friendly. It offers good sensitivity and sufficient selectivity for the routine assay of the selected penicillins. The repeatabilities were <1.9% RSD for relative peak areas and <1% RSD for migration times for all the analytes. The method showed good linearity (R2 > 0.995) within the 80-120% range of the target concentration (0.5 mg/mL) for each antibiotic. The accuracy of the method, evaluated by standard fortification at three levels, was good for all the analytes. An extended robustness study was performed by varying ±10% of the optimum value of TRIS concentration, l-histidine concentration and temperature in a full factorial design at two levels. This was to evaluate larger than usual variability of factors on the assay value, in order to better cover potential global variance in lab conditions and equipment. Finally, the method was applied for the determination of percent (%) content of all antibiotics in available formulations.
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| 4. |
- Paul, Prasanta, et al.
(författare)
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Capillary electrophoresis with capacitively coupled contactless conductivity detection method development and validation for the determination of azithromycin, clarithromycin, and clindamycin
- 2017
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Ingår i: Journal of Separation Science. - : Wiley-VCH Verlagsgesellschaft. - 1615-9306 .- 1615-9314. ; 40:17, s. 3535-3544
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Tidskriftsartikel (refereegranskat)abstract
- A capillary electrophoresis with capacitively coupled contactless conductivity detection based method for the assay of azithromycin, clarithromycin and clindamycin was optimized and validated in this study. A buffer solution of 20 mM 2-(N-morpholino) ethane sulfonic acid, 40 mM L-histidine and 0.6 mM cetyltrimethylammonium bromide (pH 6.39) was used for the electrophoresis. An uncoated, bare-fused silica capillary (total length 60 cm, effective length 32 cm, 75 mu m id) was used at 25 degrees C. The sample was injected hydrodynamically at 0.5 psi for 5 s. The electrophoresis was conducted at 30 kV in reverse polarity for 6 min with 3 and 2 min of in-between sodium hydroxide (0.1 M) and background electrolyte rinsing, respectively. Ammonium acetate was used as internal standard. This simple and robust method showed reasonable limit of detection and limit of quantitation for azithromycin (0.0125/0.03 mg/mL), clarithromycin (0.017/0.03 mg/mL), and clindamycin (0.038/0.06 mg/mL), with good selectivity, precision both intraday (relative standard deviation <= 1.0%) and interday (relative standard deviation < 3.7%), linearity (R-2 > 0.999) and recovery (99 - 101.7%). The method was successfully applied for the determination of azithromycin, clarithromycin and clindamycin in formulations.
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| 5. |
- Paul, Prasanta, et al.
(författare)
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Development and Validation of a CE Method for the Determination of Tetracyclines with Capacitively Coupled Contactless Conductivity Detection
- 2019
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Ingår i: Chromatographia. - : SPRINGER HEIDELBERG. - 0009-5893 .- 1612-1112. ; 82:9, s. 1395-1403
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a simple and robust capillary electrophoresis method with capacitively coupled contactless conductivity detection ((CD)-D-4) is developed for the determination of the tetracycline antibiotics (1) tetracycline, (2) chlortetracycline and (3) oxytetracycline. An uncoated, fused silica capillary (60.2 cm long, 75 mu m i.d.) and a solution of 50 mM tris(hydroxymethyl) aminomethane, 50 mM l-histidine and 5 mM methyl-beta-cyclodextrin, without pH adjustment (pH 8.76), was used as background electrolyte. Electrophoresis at + 25 kV showed a rapid analysis with sufficient resolution among the three antibiotics in the order of tetracycline, chlortetracycline and oxytetracycline. Successive inter-injection rinsing (20 psi) of the capillary ensured intra- and inter-day repeatability (0.9-2.2% RSD and 2.0-4.5% RSD, respectively, for relative peak areas). The method showed satisfactory performance in terms of selectivity, accuracy (99.3-101.4%) and linearity (R-2 = 0.999). Finally, the method was applied to commercial samples of tetracycline, oxytetracycline and chlortetracycline. This method can be applied for rapid quality control in developing countries in particular, and across the globe in general.
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| 6. |
- Paul, Prasanta, et al.
(författare)
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Recent advances in the capillary electrophoresis analysis of antibiotics with capacitively coupled contactless conductivity detection
- 2018
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Ingår i: Journal of Pharmaceutical and Biomedical Analysis. - : ELSEVIER SCIENCE BV. - 0731-7085 .- 1873-264X. ; 158, s. 405-415
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Forskningsöversikt (refereegranskat)abstract
- This review describes briefly the high rate of counterfeiting of antimicrobial drugs with focus upon its immediate health consequences. The major part of this review encompasses accounts of the improvements achieved in the domain of miniaturization of capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-(CD)-D-4). The application of this principle into the development of portable devices as well as its application to counter the health-system-crippling phenomenon of counterfeit antibiotic formulations, are discussed in the context of developing countries.
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| 7. |
- van Tricht, Ewoud, et al.
(författare)
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Implementation of at-line capillary zone electrophoresis for fast and reliable determination of adenovirus concentrations in vaccine manufacturing
- 2019
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Ingår i: Electrophoresis. - : Wiley. - 0173-0835 .- 1522-2683. ; 40:18-19, s. 2277-2284
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Tidskriftsartikel (refereegranskat)abstract
- A CZE method was validated and implemented for fast and accurate in-process determination of adenovirus concentrations of downstream process samples obtained during manufacturing of adenovirus vector-based vaccines. An analytical-quality-by-design approach was embraced for method development, method implementation, and method maintenance. CZE provided separation of adenovirus particles from sample matrix components, such as cell debris, residual DNA and proteins. The intermediate precision of the virus particle concentration was 6.9% RSD and the relative bias was 2.3%. In comparison, the CZE method is intended to replace a quantitative polymerase chain reaction method which requires three replicates in three analytical runs to achieve an intermediate precision of 8.1% RSD. Given that, in addition, the time from sampling till reporting results of the CZE method was less than 2 h, whereas quantitative polymerase chain reaction requires 3 days, it follows that the CZE method enables faster processing times in downstream processing.
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| 8. |
- van Tricht, Ewoud, et al.
(författare)
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One single, fast and robust capillary electrophoresis method for the direct quantification of intact adenovirus particles in upstream and downstream processing samples
- 2017
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Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 166, s. 8-14
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Tidskriftsartikel (refereegranskat)abstract
- During development of adenovirus-based vaccines, samples have to be analyzed in order to either monitor the production process or control the quality and safety of the product. An important quality attribute is the total concentration of intact adenoviruses, which currently is determined by quantitative polymerase chain reaction (qPCR) or anion exchange-HPLC. Capillary Electrophoresis (CE) was evaluated as alternative to the current methods with the aim to have one single method that allows reliable and fast quantification of adenovirus particles throughout the full process. Intact adenoviruses samples from downstream processing and upstream processing were analyzed directly by CE with UV-detection at 214 nm. Only the samples with high amounts of DNA required a simple sample pretreatment by benzonase. Adenovirus particles were separated from matrix components such as cell debris, residual cell DNA, and/or proteins on a PVA-coated capillary using a BGE consisting of 125 mM Tris, 338 mM tricine and 0.2% v/v polysorbate-20 at pH 7.7. Full factorial design of experiments was used for method optimization as part of the analytical quality by design (AQbD) method development approach. The method was validated for the quantification of adenoviruses on five representative samples from the manufacturing process in the range of 0.5 x10(11)-1.5 x10(11) adenovirus particles per ml (similar to 80 to 250 pmo1/1). The CE method showed intermediate precision of 7.8% RSD on concentration and an accuracy (spiked recovery) of 95-110%. CE proved highly useful for process development support and is being implemented for in-process control testing for adenovirus vaccine manufacturing.
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| 9. |
- Wiesner, Rebecca, et al.
(författare)
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An interlaboratory capillary zone electrophoresis-UV study of various monoclonal antibodies, instruments, and ε-aminocaproic acid lots
- 2023
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Ingår i: Electrophoresis. - : Wiley. - 0173-0835 .- 1522-2683. ; 44:15-16, s. 1247-1257
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Tidskriftsartikel (refereegranskat)abstract
- Capillary zone electrophoresis ultraviolet (CZE-UV) has become increasingly popular for the charge heterogeneity determination of mAbs and vaccines. The ε-aminocaproic acid (eACA) CZE-UV method has been used as a rapid platform method. However, in the last years, several issues have been observed, for example, loss in electrophoretic resolution or baseline drifts. Evaluating the role of eACA on the reported issues, various laboratories were requested to provide their routinely used eACA CZE-UV methods, and background electrolyte compositions. Although every laboratory claimed to use the He et al. eACA CZE-UV method, most methods actually deviate from He's. Subsequently, a detailed interlaboratory study was designed wherein two commercially available mAbs (Waters’ Mass Check Standard mAb [pI 7] and NISTmAb [pI 9]) were provided to each laboratory, along with two detailed eACA CZE-UV protocols for a short-end, high-speed, and a long-end, high-resolution method. Ten laboratories participated each using their own instruments, and commodities, showing excellence method performance (relative standard deviations [RSDs] of percent time-corrected main peak areas from 0.2% to 1.9%, and RSDs of migration times from 0.7% to 1.8% [n = 50 per laboratory], analysis times in some cases as short as 2.5 min). This study clarified that eACA is not the main reason for the abovementioned variations.
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| 10. |
- Yao, Han, et al.
(författare)
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Development of a capillary zone electrophoresis method to quantify E. coli L-asparaginase and its acidic variants
- 2018
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Ingår i: Talanta. - : ELSEVIER SCIENCE BV. - 0039-9140 .- 1873-3573. ; 182, s. 83-91
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Tidskriftsartikel (refereegranskat)abstract
- A capillary zone electrophoresis (CZE) method with UV detection was developed for the quantification of the E.coli L-asparaginase (L-ASNase) and its acidic variants. During the initial method development, a variety of experimental conditions were screened. Subsequently, a Design of Experiments (DoE) was used to optimize the pH and concentration of the selected background electrolyte (BGE) containing both TRIS and boric acid. Optimization was performed taking into account both the separation efficiency of L-ASNase and its acidic variants as well as overall method robustness. A repeatable separation between E.coli L-ASNase and its acidic variants was achieved on a bare fused silica capillary in combination with a BGE consisting of both 400 mM TRIS and boric acid. The method was validated for linearity, accuracy, precision, LOD, LOQ and robustness. The recovery for L-ASNase was 97.9-104.4% with a precision RSD of 1.5-3.2%, while the recovery of impurities was 92.1-109.8% with a RSD of 1.7-4.6%. The quantification limit was 1.9% (m/m). Moreover, the CZE-UV method was applied to determine the degradation rate in the presence of ammonium bicarbonate, confirming the suitability of the method. The degraded, partially charged L-ASNase was evaluated for its in-vitro enzymatic activity showing an insignificant different enzyme activity compared to the unmodified sample.
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