https://orcid.org/0000-0003-3822-7588
Figures
Abstract
For routine measurement of Voriconazole (VZ) in a pure and gel formulation, a quick and accurate RP-HPLC technique with UV detection (254 nm) was developed. With a flow rate of 1.0 ml/min using a mobile phase that contained acetonitrile and water mixed 50:50, v/v. Internal standard approach was used for quantification. The method shows good linearity (correlation coefficient = 0.9999) with acceptable accuracy, precision and robustness. Three elements were taken into account to measure robustness. Flow rate, mobile phase composition, and pH all have an impact on the response, but only the flow rate which causes a reduction in the concentration of the drug—has a significant impact on the response. Analyst, equipment, and days were taken into consideration for a precision measurement. The analytical procedure had good precision, as seen by the %RSD which is found to be less than 2.0. The proposed method was straightforward, extremely sensitive, exact, and accurate, and it had a retention time of less than 4 minutes, indicating that it is appropriate for daily quality control.
Citation: Sheikh S, Beg AE, Baig MT, Ibrahim S, Huma A, Jabeen A, et al. (2024) High-performance liquid chromatographic method for determination of voriconazole in pure and gel formulation. PLoS ONE 19(12): e0315704. https://doi.org/10.1371/journal.pone.0315704
Editor: António Machado, Universidade dos Açores Departamento de Biologia: Universidade dos Acores Departamento de Biologia, PORTUGAL
Received: July 13, 2024; Accepted: December 1, 2024; Published: December 16, 2024
Copyright: © 2024 Sheikh et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the manuscript.
Funding: The author(s) received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Abbreviations: VZ, Voriconazole; HPLC, High Pressure Liquid Chromatography; LOD, Limit of detection; LOQ, limit of quantification; FDA, Food and Drug Administration; TEA, Tri-ethanol amine
Introduction
Voriconazole (VZ) (Fig 1), is an extensive-spectrum antifungal drug from the triazole class [1], against a variety of fungal infections, such as those caused by Aspergillus and Candida species [2]. VZ, which is structurally derived from fluconazole [3] (Fig 1), is used for a crucial treatment of invasive fungal infections, especially in individuals with impaired immune systems, due to its increased potency and wider range of action [4]. VZ is a white, crystalline powder that dissolves very well in organic solvents like acetone and methanol but weakly in water [5]. Its distinguishing chemical characteristic is a triazole ring that binds tightly to fungal cytochrome P450 enzymes and inhibits the synthesis of ergosterol, an essential component of fungal cell membranes [6].
Chemical structure of voriconazole (a) and fluconazole (b).
VZ has a strong therapeutic profile that works against a variety of fungal infections, therefore it can be used in various dose formulations [7]. It is currently offered in several forms, including suspensions, intravenous injections, and oral tablets [8]. The analytical evaluation of VZ is crucial for assuring its effectiveness and quality in pharmaceutical formulations. Various analytical techniques have been used to estimate VZ in its pure and in pharmaceutical formulations, these techniques include high-performance liquid chromatography (HPLC) [9–11], ultra-performance liquid chromatography (UPLC) [12–20], Liquid chromatography-tandem mass spectrometry(LC-MS/MS) [21–30], high-performance tin-layer chromatography (HPTLC) [10, 31–38], UV-visible spectroscopy [39–48] and capillary electrophoresis [9, 49–56]. HPLC is the most extensively employed because of its sensitivity, specificity, and reproducibility [57–63]. HPLC techniques commonly use reverse-phase columns, such as C18 with a UV detector to detect VZ [10]. It is essential to optimize variables including the composition of the mobile phase, flow rate, and detection wavelength to precisely quantify and separate VZ from any contaminants or degradation products [11].
Each technique has distinctive benefits and precise applications, depending on the desired level of sensitivity, sample complexity, and available instrumentation. Because it strikes an acceptable balance between accuracy and effectiveness, HPLC is still the industry standard, especially for routine quality control [64]. The details of the previously developed HPLC methods for the determination of VZ in pure and pharmaceutical formulations are given in Table 1. Previous HPLC methods developed for the determination of VZ are time-consuming, tedious, expensive and need pretreatment of the samples. So, therefore, the present study aims to develop and validate an easy, affordable, sensitive, reliable, precise and robust HPLC method for the determination of VZ in pure and gel formulations.
Materials and methods
Chemicals
VZ (>98.0%) was purchased from Sigma Aldrich (St. louis, MO, USA). All the solvents and reagents used in this study were of HPLC grade and used without any prior purification.
pH measurements
pH measurements of VZ were carried out by LCD pH meter, (Elmetron CP-500, sensitivity±0.01 pH units Poland). Calibration of pH meter was carried out by using commercially available buffer tablets of pH 4.0, 7.0, and 9.0.
Preparation of gel formulation
VZ dissolved in ethanol with the help of a magnetic stirrer for 30 minutes until a clear solution was formed. Different excipients were used to prepare the hydrogels at different concentrations that is given in Table 2. Every time a precisely measure quantity of carbomer was added in small amounts to a glass container filled with water, stirring continuously to prevent the formation of lumps using a glass rod and a mechanical mixer for 15 min at a speed of 500 rpm to completely dissolve the polymer this would result in the formation of a gel. A solubilizing and pH-adjusting triethanol amine (TEA) is added until the desired pH is obtained, and the remaining water and humectant are added and mixed thoroughly for a further 30 min. VZ solution was added at the end of the stirring for a further 10 min. The formulated gel is allowed to settle for 24 hours before subjecting them to analysis. For each formulation, the placebo gel was likewise made identically [80, 81].
Chromatographic condition
The HPLC apparatus was Shimadzu chromatographic system (20A autosampler) with a variable wavelength programmable UV-Vis detector, a reversed-phase column (L1, 5μ) 4.6× 150mm. Prepare a mixture of acetonitrile and water (1:1, v/v). Stirrer for 5 minutes and allow to equilibrate at room temperature. Filter this solution through a 0.22-micron membrane filter and use the filtrate as a mobile phase. Acetonitrile and water (50:50 v/v) served as the mobile phase, and the flow rate was 1 mL per minute. The temperature was set to 30±1°C, and the UV detector’s wavelength was 254 nm.
Preparation of reference standard solution
Weight accurately 0.05 mg (50 μg) of the reference standard of VZ into 100 mL of volumetric flask. Add 100 ml of mobile phase and dissolve it by stirring.
Preparation of test solutions
Weigh the gel about 2gm (equivalent to about 60mg of voriconazole) and transfer it accurately to a 200mL volumetric flask, adding 50mL of diluent dissolved by mechanical shaking. Make up the volume with diluent and mix. Filter a portion of this solution through a 0.22-micron membrane filter and use the filtrate as a test solution.
Method validation
The proposed HPLC method was validated according to the guidelines of the International Council of Harmonization [82]. The details of the method validation parameter are discussed below:
System suitability.
Inject 5 replicates of the reference solution (45 μg/100 mL) and check the system suitability criteria for tailing factor and relative standard deviation. Inject in triplicate the test solution and record the chromatograms.
Linearity and range.
The plot of peak Area (AU) versus the corresponding concentrations of the prepared solutions (3.5–45 μg/mL) has been prepared. The prepared calibration curve is used to calculate the slope, intercept, standard deviation, standard deviation, standard error and correlation coefficient. The linearity of the calibration curves was used to determine the range for the assay of VZ.
Accuracy.
The accuracy of the proposed method was assessed by making known concentrations of VZ from the standard solutions (15.0, 30.0, and 45.0 μg/100 mL) from the stock solution. The known concentrations were made in duplicate and put through an assay to see the accuracy of the method.
Precision.
Dilutions of VZ (30.0μg/100 mL) were prepared to check the repeatability (intra-day) and intermediate (inter-day) precision of the method. To assess the precision of the suggested method, relative standard deviation (%RSD) was computed.
Limit of detection (LOD) and limit of quantification (LOQ).
The standard deviation of the slope was used to calculate the LOD and LOQ of the procedure by using the formulas:
Where, σ = standard deviation of intercept and S = slope.
Result and discussion
Method validation
The developed and validated HPLC method improves on previously reported HPLC methods by addressing the demands of sensitivity, selectivity, accuracy, precision, robustness, and specificity for the quantification of VZ. Various parameters have been studied to optimize the analysis conditions, including solvent system composition (acetonitrile:water, 10:90, 15:85, 20:80, 25:75, 30:70, 40:60, and 50:50, v/v), pH of the mobile phase (2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, and 6.5), and flow rate of the mobile phase (0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1.0 mL/min). After multiple trials using the above-mentioned conditions, the proposed method has been validated using acetonitrile:water (50:50, v/v) with a flow rate of 1.0 mL/min at pH 5.0 to obtain accurate, precise, robust, reliable, and specific results for the estimation of VZ.
System suitability.
Before the method validation, the system suitability of the proposed method has been determined and the results obtained are reported in Table 3. The results obtained are found to be in the acceptable range with a tR of 3.782 min (Fig 2). The %RSD was found to be less than 2% and the theoretical plates were found to be 2196 with a tailing factor of less than 1.110 (Table 3).
Linearity and range.
The proposed method was found to be linear in the concentration range of 3.5–45.0 μg/100 mL. Table 4 presents the statistical analysis of these findings. With correlation coefficients (R2) of 0.9999, respectively, there is a negligible scatter in the calibration curves’ points (Fig 3). The purity of these compounds is shown by the fact that the y-intercepts for the measurement of VZ are near zero.
Accuracy.
The proposed method’s accuracy in determining VZ was 99.76±0.68, 100.0±0.37, and 100.1±0.18 respectively. The results show that the estimated concentrations and the applied concentrations agree, according to the results. In Table 5, findings from the method’s accuracy assessment are shown. The relative accuracy error (%), standard deviation, and percent RSDs were found to be minimal, demonstrating the method’s high degree of accuracy for identifying these compounds.
Precision.
It measures the dispersion between chemical results made after many samples were taken with identical concentrations and under the same circumstances. The results of the precision studies are shown in Table 6, and the fact that the %RSDs was less than 1% showed that this technique is suitable for determining VZ.
Limit of detection.
It is the minimum concentration of the analyte that could be identified but not quantified. The LODs for the assay of VZ were found to be 1.06 μg/100 mL, respectively (Table 4), this demonstrates that this approach is quite sensitive for identifying all of these compounds.
Limit of quantification.
It involves quantifying the analyte’s lowest concentration and drugs with good precision and accuracy. The values of LOQs for determining VZ were found to be 3.22μg/100 mL, respectively.
Robustness.
It demonstrates that the testing method is unaffected by any little intentional alterations and demonstrates the method’s compatibility and durability. The deliberate changes in temperature (±5°C), wavelength (±2 nm) and flow rate (± 0.2 mL/min), as well as the accuracy and precision data collected following those adjustments, are given in Table 7. The accuracy and precision (%RSDs) for the identification of VZ after deliberate changes are 99.86–100.01,98.99–100.1, 99.99–100.1 and 0.11–0.22, 0.32–0.88, 0.44–0.51, respectively. The statistical comparison between the proposed method conditions and after making the deliberate changes has been carried out (Table 7). It has been found that there is no significant difference between the proposed method conditions and the deliberate changes made. The calculated t values are less than that of tabulated t values indicating that there is no significant difference and confirming that the method is reliable, sensitive, accurate, and precise. These outcomes demonstrate that the modifications made to the measurement have no impact on the method’s accuracy and precision.
Specificity.
The ability of the analytical method to detect and quantify the analyte of choice in the presence of impurities and degradation products is how specific the developed method is. The forced degradation studies have been carried out to observe the specificity of the developed HPLC method for the determination of VZ. The solution of VZ has been prepared and exposed to the particular stress conditions for 2 hours and afterward subjected to the HPLC analysis. The results obtained are given in Table 8. It has been found that maximum degradation of VZ occurs via alkaline hydrolysis (82.33%), followed by UV light (10.64%) and heat (7.55%). The maximum degradation of VZ in alkaline hydrolysis is due to the higher susceptibility of its anionic form to alkaline conditions, as reported earlier [83]. However, minimum degradation has been found in the case of acid hydrolysis (3.71%) and oxidative stress (2.55%) [83]. This may be due to the lower sensitivity of VZ in its cationic form to acid hydrolysis. Acid, base hydrolysis, and oxidation degradation show no interfering peak at the analyte’s retention time and no degradation peak because of using a UV detector instead of a PDA detector, which is not available in our laboratory.
Application of proposed HPLC method
The developed and validated HPLC method is found to be accurate (Table 5), precise (Table 6), less time-consuming (tR = 3.782, Table 3), simple, sensitive (Table 4), and economic (less amount of organic solvent (acetonitrile) used) as compared to that of the previously reported HPLC methods. So, therefore, the reliability, sensitivity, and selectivity of the proposed HPLC method have been checked by applying it to the gel formulations. The proposed HPLC method was applied to determine the concentration of VZ in the gel formulation. The gel formulation was dissolved in ethanol and subjected to the HPLC analysis. The obtained chromatogram is given in Fig 4. It has been found that the excipients (i.e carbomer, PG, TEA) used for the preparation of the gel do not show interference. The results obtained were found to be in the range of 98.00–102.7% with a %RSD of 0.88–1.31 (Table 9), so, therefore the proposed method could be commercially used for the analysis of VZ in gel formulations.
Conclusion
The HPLC method has been developed and validated for the assay of voriconazole (VZ) in pure form and its gel formulation. The proposed method is rapid, simple, sensitive, accurate, precise, robust, and specific for the estimation of VZ. This HPLC method is stability-indicating because of its specificity in determining VZ in the presence of degradation products. Also, this method is less time-consuming as the VZ peak appears at 3.8 min and is economical due to the simple mobile phase system with lesser quantity. The developed HPLC method is also successfully applied to the gel formulations for the estimation of VZ.
References
- 1.
Rauseo AM, Coler-Reilly A, Larson L, Spec A. Hope on the horizon: Novel fungal treatments in development. In open forum infectious diseases 2020; 7: ofaa016. US: Oxford University Press.
- 2.
Malani AN, Kerr LE, Kauffman CA. Voriconazole: How to use this antifungal agent and what to expect. In seminars in respiratory and critical care medicine 2015; 36: 786–795. Thieme Medical Publishers.
- 3. Teixeira MM, Carvalho DT, Sousa E, Pinto E. New antifungal agents with azole moieties. Pharmaceuticals. 2022; 15:1427. pmid:36422557
- 4. Job KM, Olson J, Stockmann C, Constance JE, Enioutina EY, Rower JE, et al. Pharmacodynamic studies of voriconazole: informing the clinical management of invasive fungal infections. Expert review of anti-infective therapy. 2016;14:731–746. pmid:27355512
- 5. Shafie MAA, Mohamed MA-AH, Mohamed AA-EZS. Topical Delivery of Voriconazole Loaded on Lyotropic Liquid Crystal Gel for Management of Fungal Infections. Journal of Pharmaceutical Research. 2024; 23: 90.
- 6. Warrilow AG, Parker JE, Price CL, Rolley NJ, Nes WD, Kelly DE, et al. Isavuconazole and voriconazole inhibition of sterol 14α-demethylases (CYP51) from Aspergillus fumigatus and Homo sapiens. International Journal of Antimicrobial Agents. 2019; 54: 449–455.
- 7. Mikulska M, Novelli A, Aversa F, Cesaro S, de Rosa FG, Girmenia C, et al. Voriconazole in clinical practice. Journal of Chemotherapy. 2012; 24: 311–327. pmid:23174096
- 8.
Nivoix Y, Ledoux MP, Herbrecht R. Antifungal therapy: New and evolving therapies. In Seminars in respiratory and critical care medicine 2020; 41: 158–174. Thieme Medical Publishers.
- 9. Hussain A, A lAjmi MF, Hussain I, Ali I. Future of ionic liquids for chiral separations in High-Performance Liquid Chromatography and Capillary Electrophoresis. Critical Reviews in Analytical Chemistry. 2019; 49: 289–305. pmid:30582712
- 10. Musirike MR, Reddy KH, Mallu UR. Stability indicating Reverse Phase Chromatographic method for estimation of related substances in Voriconazole drug substance by Ultra Performance Liquid Chromatography. Pharm Analytica Acta. 2016; 7: 460.
- 11. Nanda BP, Chopra A, Kumari Y, Narang RK, Bhatia R. A comprehensive exploration of diverse green analytical techniques and their influence in different analytical fields. Separation Science Plus. 2024; 7: 2400004.
- 12. Blanco-Dorado S, Medall MD, Pascual-Marmaneu O, Campos-Toimil M, Otero-Espinar FJ, Rodríguez-Riego R, et al. Therapeutic drug monitoring of voriconazole: validation of a High Performance Liquid Chromatography method and comparison with an ARK immunoassay. European Journal of Hospital Pharmacy. 2021; 28:154–159.
- 13. Boeira P, Antunes MV, Andreolla HF, Pasqualotto AC, Linden R. Ultra-Performance Liquid Chromatographic method for measurement of voriconazole in human plasma and oral fluid. Journal of the Brazilian Chemical Society. 2012; 23: 148–155.
- 14. Cattoir L, Fauvarque G, Degandt S, Ghys T, Verstraete AG, Stove V. Therapeutic drug monitoring of voriconazole: validation of a novel ARK™ immunoassay and comparison with Ultra-High Performance Liquid Chromatography. Clinical Chemistry and Laboratory Medicine. 2015; 53: 135–139.
- 15. Decosterd LA, Rochat B, Pesse B, Mercier T, Tissot F, Widmer N, et al. Multiplex Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry method for simultaneous quantification in human plasma of fluconazole, itraconazole, hydroxyitraconazole, posaconazole, voriconazole, voriconazole-N-oxide, anidulafungin, and caspofungin. Antimicrobial Agents and Chemotherapy. 2010; 54: 5303–5315. pmid:20855739
- 16. Li J, Ma J, Wagar EA, Liang D, Meng QH. A rapid Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry assay for determination of serum unbound fraction of voriconazole in cancer patients. Clinica Chimica Acta. 2018; 486: 36–41.
- 17. Peña-Lorenzo D, Rebollo N, Sánchez-Hernández JG, Zarzuelo-Castañeda A. Comparison of ultra-performance liquid chromatography and ARK immunoassay for therapeutic drug monitoring of voriconazole. Annals of Clinical Biochemistry. 2021; 58: 657–660. pmid:34482744
- 18. Pieters S, Dejaegher B, Vander Heyden Y. Emerging analytical separation techniques with high throughput potential for pharmaceutical analysis, part I: Stationary phase and instrumental developments in Liquid Chromatography. Combinatorial Chemistry & High Throughput Screening. 2010;13: 510–529.
- 19. Verweij-van Wissen CP, Burger DM, Verweij PE, Aarnoutse RE, Brüggemann RJ. Simultaneous determination of the azoles voriconazole, posaconazole, isavuconazole, itraconazole and its metabolite hydroxy-itraconazole in human plasma by Reversed Phase Ultra-Performance Liquid Chromatography with ultraviolet detection. Journal of Chromatography B. 2012; 887: 79–84.
- 20. Yu M, Yang J, Xiong L, Zhan S, Cheng L, Chen Y, et al. Comparison of Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry and Enzyme-Multiplied Immunoassay Technique for quantification of voriconazole plasma concentration from Chinese patients. Heliyon. 2023; 9: 2405–8440.
- 21. Araujo B, Conrado D, Palma E, Dalla Costa T. Validation of rapid and simple Liquid Chromatography with Tandem Mass Spectrometry method for determination of voriconazole in rat plasma. Journal of Pharmaceutical Biomedical Analysis. 2007; 44: 985–990.
- 22. Dong L, Bai N, Wang T, Cai Y. Development and validation of a Liquid Chromatography-Tandem Mass Spectrometry method for the quantification of voriconazole in human cerebrospinal fluid. Analytical Methods. 2021; 13:4585–4593.
- 23. Jenkins N, Black M, Schneider HG. Simultaneous determination of voriconazole, posaconazole, itraconazole and hydroxy-itraconazole in human plasma using Liquid Chromatography with Tandem Mass Spectrometry. Clinical Biochemistry. 2018; 53: 110–115.
- 24. Mak J, Sujishi KK, French D. Development and validation of a Liquid Chromatography-Tandem Mass Spectrometry assay to quantify serum voriconazole. Journal of Chromatography B. 2015; 986: 94–99.
- 25. Mei H, Hu X, Wang J, Wang R, Cai Y. Determination of voriconazole in human plasma by Liquid Chromatography-Tandem Mass Spectrometry and its application in therapeutic drug monitoring in Chinese patients. Journal of International Medical Research. 2020; 48.
- 26. Pauwels S, Vermeersch P, Van Eldere J, Desmet K. Fast and simple Liquid Chromatography-Tandem Mass Spectrometry method for quantifying plasma voriconazole. Clinica Chimica Acta. 2012; 413: 740–743.
- 27. Prommas S, Puangpetch A, Jenjirattithigarn N, Chuwongwattana S, Jantararoungtong T, Koomdee N, et al. Development and validation of voriconazole concentration by LC‐MS‐MS: applied in clinical implementation. Journal of Clinical Laboratory Analysis. 2017; 31: e22011. pmid:27337994
- 28. Wadsworth JM, Milan AM, Anson J, Davison AS. Development of a Liquid Chromatography Tandem Mass Spectrometry method for the simultaneous measurement of voriconazole, posaconazole and itraconazole. Annals of Clinical Biochemistry. 2017; 54: 686–695. pmid:27941128
- 29. Xiao Y, Xu YK, Pattengale P, O’Gorman MR, Fu X. A rapid High-Performance Liquid Chromatography Tandem Mass Spectrometry method for therapeutic drug monitoring of voriconazole, posaconazole, fluconazole, and itraconazole in human serum. The Journal of Applied Laboratory Medicine. 2017; 1: 626–636.
- 30. Xiong X, Zhai S, Duan J. Validation of a fast and reliable Liquid Chromatography-Tandem Mass Spectrometry with atmospheric pressure chemical ionization method for simultaneous quantitation of voriconazole, itraconazole and its active metabolite hydroxyitraconazole in human plasma. Clinical Chemistry Laboratory Medicine. 2013; 51: 339–346.
- 31. Chanduluru HK, Sugumaran A. Assessment of greenness for the determination of voriconazole in reported analytical methods. RSC Advances. 2022; 12: 6683–703. pmid:35424637
- 32. Dewani MG, Borole TC, Gandhi SP, Madgulkar A, Damle MC. Development and validation of High-Performance Thin-Layer Chromatography method for determination of voriconazole in human plasma. Der Pharma Chemica. 2011; 201–209.
- 33. Jain MW, Shirkhedkar AA, Surana SJ. Reverse Phase-High-Performance Thin-Layer Chromatography method for determination of Voriconazole in bulk and in cream formulation. Arabian Journal of Chemistry. 2017; 10: S355–S360.
- 34. Khalil HA, El-Yazbi AF, Hamdy DA, Belal TS. Application of High-Performance Thin-Layer Chromatography, spectrofluorimetry and differential pulse voltammetry for determination of the antifungal drug posaconazole in suspension dosage form. In Annales Pharmaceutiques Francaises 2019; 77: 382–393).
- 35. Khetre AB, Darekar RS, Sinha PK, Jeswani RM, Damle MC. Validated High-Performance Thin-Layer Chromatography method for determination of voriconazole in bulk and pharmaceutical dosage form. Rasayan Journal of Chemistry. 2008; 1: 542–7.
- 36. Narayana PS, Reddy AS, Ramesh B, Devi PS. Simultaneous determination and method validation of Fluconazole and its impurities by High Performance Thin Layer Chromatography using Reflectance Scanning Densitometry. Eurasian Journal of Analytical Chemistry. 2013; 8: 39–49.
- 37. Parikh SK, Dave JB, Patel CN, Ramalingan B. Stability-indicating High-Performance Thin-Layer Chromatographic method for analysis of Itraconazole in bulk drug and in pharmaceutical dosage form. Pharmaceutical Methods. 2011; 2: 88–94. pmid:23781436
- 38. Raghubabu K, Jagannadharao V, Ramu BK. Extractive Visible Spectrophotometric determination of Voriconazole in tablet dosage form using Ion-association methods. Asian Journal of Research In Chemistry. 2012; 5: 595–599.
- 39. Adams AI, Steppe M, Frehlich PE, Bergold AM. Comparison of Microbiological and UV-spectrophotometric assays for determination of Voriconazole in tablets. Journal of AOAC International 2006; 89: 960–965. pmid:16915830
- 40.
Agbaba D, Čarapić M. Applications of thin-layer chromatography in the pharmaceutical industry. Instrumental Thin-Layer Chromatography: Elsevier; 2023: 519–573.
- 41. Bhaduka G, Rajawat JS. Formulation development and solubility enhancement of voriconazole by solid dispersion technique. Research Journal of Pharmacy Technology. 2020; 13: 4557–4564.
- 42. Bhosale R, Bhandwalkar O, Duduskar A, Jadhav R, Pawar P. Water soluble chitosan mediated voriconazole microemulsion as sustained carrier for ophthalmic application: in vitro/ex vivo/in vivo evaluations. Open Pharmaceutical Sciences Journal. 2016; 3: 215–234.
- 43. El-Emam GA, Girgis GN, El-Sokkary MMA, El-Azeem Soliman OA, Abd El Gawad AEGH. Ocular inserts of Voriconazole-loaded proniosomal gels: formulation, evaluation and microbiological studies. International Journal of Nanomedicine. 2020; 15: 7825–7840. pmid:33116503
- 44. Kumar R, Sinha VJC, Biointerfaces SB. Preparation and optimization of Voriconazole microemulsion for ocular delivery. Colloids and Surfaces B: Biointerfaces. 2014; 117: 82–88. pmid:24632034
- 45. Ladetto MF, Lázaro-Martínez JM, Devoto TB, Briceño VJ, Castro GR, Cuestas ML. Quantitative determination of Voriconazole by thionine reduction and its potential application in a pharmaceutical and clinical setting. Analytical Methods. 2023; 15: 1230–1240. pmid:36807654
- 46. Mushtaq M, Shah Y, Samiullah , Nasir F, Khan H, Faheem M, et al. Determination of voriconazole in human plasma using Reverse Phase-High Performance Liquid Chromatography/UV-visible detection: Method development and validation; subsequently evaluation of voriconazole pharmacokinetic profile in Pakistani healthy male volunteers. Journal of Chromatographic Science. 2022; 60: 633–641.
- 47. Shah MKA, Azad AK, Nawaz A, Ullah S, Latif MS, Rahman H, et al. Formulation development, characterization and antifungal evaluation of chitosan NPs for topical delivery of Voriconazole in vitro and ex vivo. Polymers. 2021; 14: 135. pmid:35012154
- 48. Tamilselvi N, Hassan B, Fadul FB, Kondapalli D, Anusha K, Kurian DS. UV Spectrophotometric estimation of Voriconazole in tablet dosage form. Research Journal of Pharmacy Technology. 2011; 4: 1791–1793.
- 49. Azhari NRB, Hui BY, Zain NNM, Suah FBM, Mohamad S, Yahaya N, et al. Enantiomeric separation of azole antifungal compounds using Chromatographic and Electrophoretic techniques: a mini-review. Sains Malaysiana. 2020; 49: 2699–2714.
- 50. Codevilla CF, Rosa P, Steppe M, Bergold AM, Rolim CMB, Adams AIH. Development and validation of a stability-indicating Micellar Electrokinetic Chromatography method to assay voriconazole tablets. Analytical Methods. 2013; 5: 5051–5057.
- 51. Crego AL, Marina ML, Lavandera J. Optimization of the separation of a group of antifungals by Capillary Zone Electrophoresis. Journal of Chromatography A. 2001; 917: 337–345. pmid:11403486
- 52. Ekiert R, Krzek J, Talik P. Chromatographic and Electrophoretic techniques used in the analysis of triazole antifungal agents-a review. Talanta. 2010; 82: 1090–1100. pmid:20801303
- 53. Liang H-H, Lin Y-C, Hung C-C, Hou Y-C, Lin Y-H. A novel cation-selective exhaustive injection and sweeping Micellar Electrokinetic Chromatography method for the simultaneous determination of second-generation triazoles in human plasma. Microchemical Journal. 2024; 196: 109703.
- 54. Lin S-C, Lin S-W, Chen J-M, Kuo C-H. Using Sweeping Micellar Electrokinetic Chromatography to determine Voriconazole in patient plasma. Talanta. 2010; 82: 653–659. pmid:20602950
- 55. Owens P, Fell A, Coleman M, Berridge J. Separation of the Voriconazole stereoisomers by Capillary Electrophoresis and Liquid Chromatography. Enantiomer. 1999; 4: 79–90. pmid:10483712
- 56. Theurillat R, Zimmerli S, Thormann W. Determination of Voriconazole in human serum and plasma by Micellar Electrokinetic Chromatography. Journal of Pharmaceutical Biomedical Analysis. 2010; 53: 1313–1318. pmid:20541340
- 57. Khetre A, Sinha P, Damle MC, Mehendre R. Development and validation of stability indicating Reverse Phase-High Performance Liquid Chromatography method for Voriconazole. Indian Journal Of Pharmaceutical Sciences. 2009; 71: 509.
- 58. Weshahy SA-E-F, Yehia AM, Helmy AH, Youssef NF, Hassan SAE-M. Comparative kinetic studies and pH-rate profiling of aniracetam degradation using validated stability-indicating Reverse Phase-High Performance Liquid Chromatography method. Microchemical Journal. 2020; 157: 105047.
- 59. Yehia AM, Arafa RM, Abbas SS, Amer SM. Chromatographic separation of synthetic estrogen and progesterone in presence of natural congeners: Application to saliva and pharmaceutical samples. Chromatographia. 2021; 84: 1–11.
- 60. Yehia AM, El‐ghobashy MR, Helmy AH, Youssef NF. Chromatographic separation of vildagliptin and l‐proline as in‐process impurity with the application of Youden’s test and statistical analysis to test the robustness of the High Performance Liquid Chromatography method. Separation Science Plus. 2018; 1: 395–403.
- 61. Yehia AM, Essam HM. Development and validation of a generic High‐Performance Liquid Chromatography for the simultaneous separation and determination of six cough ingredients: Robustness study on core-shell particles. Journal of Separation Science. 2016; 39: 3357–3367. pmid:27404374
- 62. Yehia AM, Mohamed HM. Green approach using monolithic column for simultaneous determination of coformulated drugs. Journal of Separation Science. 2016; 39: 2114–2122. pmid:27062581
- 63. Yehia AM, Sami I, Riad SaM, El-Saharty YS. Comparison of two stability-indicating Chromatographic methods for the determination of mirabegron in presence of its degradation product. Chromatographia. 2017; 80: 99–107.
- 64. Kaur R, Saini S, Sharma T, Katare O, Kaushik A, Singh B. Implementation of analytical quality-by-design for developing a robust High-Performance Liquid Chromatogrphic method for quantitative estimation of Voriconazole: application in drug formulations. Analytical Chemistry Letters. 2021; 11: 168–186.
- 65. Okur NÜ, ÇaĞlar EŞ, YOzgatlı V. Development and validation of an High Performance Liquid Chromatogrphic method for Voriconazole active substance in bulk and its pharmaceutical formulation. Marmara Pharmaceutical Journal. 2016; 20: 79–85.
- 66. Singh S, Goyal G, Malik IA. Development and validation of Reverse Phase High-Performance Liquid Chromatographic method for estimation of voriconazole”. International Journal Of All Research Writings 2019; 1: 40–50.
- 67. Pyla S, Srinivas K, Yvv J, Panda J, Rose PS. Development and Validation of Reverse Phase High-Performance Liquid Chromatographic method for the estimation of Voriconazole in bulk and pharmaceutical dosage form. Chemical Science. 2014; 3: 1576–1582.
- 68. Blanco-Dorado S, Medall MDB, Pascual-Marmaneu O, Campos-Toimil M, Otero-Espinar FJ, Rodríguez-Riego R, et al. Therapeutic drug monitoring of Voriconazole: validation of a High-Performance Liquid Chromatography method and comparison with an ARK immunoassay. European Journal of Hospital Pharmacy 2021; 28: 154–159.
- 69. Eldin AIB, Shalaby A. Determination of Voriconazole and its degradation products in pharmaceutical formulations using High-Performance Liquid Chromatography with ultra-violet detection. Eurasian Journal of Analytical Chemistry. 2010; 5: 254–64.
- 70. Srinubabu G, Raju CA, Sarath N, Kumar PK, Rao JS. Development and validation of a High-Performance Liquid Chromatography method for t2e determination of Voriconazole in pharmaceutical formulation using an experimental design. Talanta. 2007;71(3):1424–9.
- 71. Gu P, Li Y. Development and validation of a stability-indicating High-Performance Liquid Chromatography method for determination of Voriconazole and its related substances. Journal Of Chromatographic Science 2009; 47: 594–598.
- 72. Perea S, Pennick GJ Modak A, Fothergill AW, Sutton DA, Sheehan DJ, et al. Comparison of High-Performance Liquid Chromatographic and Microbiological methods for determination of Voriconazole levels in plasma. Antimicrobial Agents Chemotherapy 2000; 44: 1209–1213. pmid:10770753
- 73. Cheng S, Qiu F, Huang J, He J. Development and validation of a simple and rapid High-Performance Liquid Chromatographic method for the quantitative determination of Voriconazole in rat and beagle dog plasma. Journal of Chromatographic Science 2007; 45: 409–414.
- 74. Chawla PK, Dherai AJ, Ashavaid TF. Plasma Voriconazole estimation by High-Performance Liquid Chromatographic method. Indian Journal of Clinical Biochemistry. 2016; 31: 209–214.
- 75. Adams A, Bergold A. Development and validation of a High-Performance Liquid Chromatographic method for the determination of Voriconazole content in tablets. Chromatographia. 2005; 62: 429–434.
- 76. Simmel F, Soukup J, Zoerner A, Radke J, Kloft C. Development and validation of an efficient High-Performance Liquid Chromatographic method for quantification of Voriconazole in plasma and microdialysate reflecting an important target site. Analytical Bioanalytical Chemistry. 2008; 392: 479–488.
- 77. Tang PH. Quantification of antifungal drug Voriconazole in serum and plasma by High-Performance Liquid Chromatographic-Ultra-Violet method. Journal of Drug Metabolism and Toxicology. 2013; 4: 2.
- 78. Epuru MR, Allaka TR, Venna RR, Narsimhula S, Kishore Pilli VVN. A new process related impurity identification, characterization, development of analytical method by High-Performance Liquid Chromatographic and method validation for Voriconazole active pharmaceutical ingredient. Acta Chromatographica. 2024.
- 79. Khetre AB, Sinha PK, Damle MC, Mehendre R. Development and validation of stability indicating RP-HPLC method for voriconazole. Indian journal of pharmaceutical sciences. 2009; 71: 509. pmid:20502568
- 80. Sahoo S, Pani NR, Sahoo SK. Microemulsion based topical hydrogel of Sertaconazole: Formulation, characterization and evaluation. Colloids and Surfaces B: Biointerfaces. 2014; 120: 193–199. pmid:24953450
- 81. Helal DA, El-Rhman DA, Abdel-Halim SA, El-Nabarawi MA. Formulation and evaluation of Fluconazole topical gel. International Journal of Pharmacy and Pharmaceutical Sciences. 2012; 4: 176–183.
- 82.
ICH Harmonized Tripartite Guideline. Validation of analytical procedures: text and methodology Q2 (R1), Paper presented at: International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use; 2005; Geneva, Switzerland.
- 83. Kasar PM, Kale KS, Phadtare DG. Formulation and evaluation of topical antifungal gel containing Itraconazole. Research Journal of Topical and Cosmetic Sciences. 2018; 9: 49–52.