Validation of an ultra-fast UPLC-UV method for the separation of antituberculosis tablets

UPLC Technique in Pharmacy—An Important Tool of the Modern Analyst

In recent years, ultra-efficient liquid chromatography (UPLC) has gained particular popularity due to the possibility of faster separation of small molecules. This technique, used to separate the ingredients present in multi-component mixtures, has found application in many fields, such as chemistry, pharmacy, food, and biochemistry. It is an important tool in both research and production. UPLC created new possibilities for analytical separation without reducing the quality of the obtained results. This technique is therefore a milestone in liquid chromatography. Thanks to the increased resolution, new analytical procedures, in many cases, based on existing methods, are being developed, eliminating the need for re-analysis. Researchers are trying to modify and transfer the analytical conditions from the commonly used HPLC method to UPLC. This topic may be of strategic importance in the analysis of medicinal substances. The information contained in this manuscript indicates the importance of the UPLC technique in drug analysis. The information gathered highlights the importance of selecting the appropriate drug control tools. We focused on drugs commonly used in medicine that belong to various pharmacological groups. Rational prescribing based on clinical pharmacology is essential if the right drug is to be administered to the right patient at the right time. The presented data is to assist the analyst in the field of broadly understood quality control, which is very important, especially for human health and treatment. This manuscript shows that the UPLC technique is now an increasingly used tool for assessing the quality of drugs and determining the identity and content of active substances. It also allows the monitoring of active substances and finished products during their processing and storage.

Quantification of pyrazinamide, isoniazid, acetyl-isoniazid, and rifampicin by a high-performance liquid chromatography method in human plasma from patients with tuberculosis

The aim of this study was to establish and validate an alternative high-performance liquid chromatography method for simultaneous quantification of pyrazinamide, isoniazid, acetyl-isoniazid and rifampicin in plasma of patients under treatment for tuberculosis. The performed method was lineal (r²  > 0.99) in the range of 2.00-50.00 μg/mL for pyrazinamide, 0.50-20.00 μg/mL for both acetyl-isoniazid and isoniazid, and 1.20-25.00 μg/mL for rifampicin. Precision and trueness were demonstrated with coefficient of variation < 15% and deviations < 15%, respectively, for quality controls samples. The lower limits of quantification were 2.00, 0.50, 0.50, and 1.20 μg/mL for pyrazinamide, isoniazid, acetyl-isoniazid and rifampicin, respectively. The method was applied for the analysis of plasma from patients with tuberculosis. This method allowed ensuring reliable quantification of the target compounds and their pharmacokinetics parameters. In general, the mean values of maximum concentration of each antituberculosis drug were located within their respective reference therapeutic ranges. However, patients with sub-therapeutic plasma concentrations of isoniazid and rifampicin were detected. This is the first analytical technique that simultaneously quantifies isoniazid, acetyl-isoniazid, rifampicin, and pyrazinamide concentrations from plasma samples by high-performance liquid chromatography with ultraviolet/visible. The proposed method could be applied for therapeutic drug monitoring and pharmacokinetics studies of the four compounds throughout the treatment of tuberculosis patients.

Strategies in developing high-throughput liquid chromatography protocols for method qualification of pharmacopeial monographs

Method qualification is a key step in the development of routine analytical monitoring of pharmaceutical products. However, when relying on published monographs that describe longer method times based on older high-performance liquid chromatography column and instrument technology, this can delay the overall analysis process for generated drug products. In this study, high-throughput ultrahigh pressure liquid chromatography techniques were implemented to decrease the amount of time needed to complete a 24-run sequence to identify linearity, recovery, and repeatability for both drug assay and impurity analysis in 16 min. Multiple experimental parameters were tested to identify a range of experimental settings that could be used for the sequence while still maintaining this fast analysis time. The full sequence was replicated on a different system and with different columns, further demonstrating its robustness.

Stability Study of Isoniazid and Rifampicin Oral Solutions Using Hydroxypropyl-Β-Cyclodextrin to Treat Tuberculosis in Paediatrics

(1) Background: First-line antituberculosis treatment in paediatrics entails the administration of Isoniazid, Pyrazinamide, and Rifampicin. This study examines the possibility of developing a combined dose liquid formulation for oral use that would facilitate dose adjustment and adherence to treatment for younger children. (2) Methods: The active pharmaceutical ingredients stability under in vitro paediatric digestive pH conditions have been checked. The samples were studied as individual or fixed combined paediatric dosages to determine the pH of maximum stability. The use of hydroxypropyl-β-cyclodextrin to improve Rifampicin solubility and the use of ascorbic acid to increase the stability of the formulation have been studied. (3) Results: Maximum stability of combined doses was determined at pH 7.4, and maximum complexation at pH 8.0. Taking this into account, formulations presented the minimum dose of two active pharmaceutical ingredients dissolved. The addition of ascorbic acid at 0.1% w/v enables the detection of a higher remaining quantity of both drugs after three days of storage at 5 °C. (4) Conclusions: a formulation which combines the minimum paediatric dosages dissolved recommended by WHO for Isoniazid and Rifampicin has been developed. Future assays are needed to prolong the stability of the formulation with the aim of incorporating Pyrazinamide to the solution.

Design and optimization of a child-friendly dispersible tablet containing isoniazid, pyrazinamide, and rifampicin for treating tuberculosis in pediatrics

Objective: Develop a child-friendly Fixed Dose Combination (FDC) water-dispersible tablet for Tuberculosis (TB) treatment, with 50, 150, and 75 mg of isoniazid, pyrazinamide and rifampicin respectively. This new formulation must contain the lowest number of excipients accepted for pediatrics and fulfill all the pharmacopeia requirements.Significance: At present, there is no adequate market dosage form available for children. There is, however, one in a prequalification phase by the World Health Organization but its composition contains excipients which may not be suitable for pediatrics. Therefore, this new formulation would cover this therapeutic gap.Methods: A factorial design, based on three quantitative factors (compression force and concentration of AcDiSol^® and Explosol^®) at three levels each, was performed to elucidate their influence over disintegration time and friability. In addition, the influence of the press speed on disintegration time, friability, tensile strength, fineness of dispersion and content uniformity over the target tablet was tested. A stability test was done following ICH guideline for accelerated conditions.Results: Tablets developed with 9% w/w of Explosol^® and a compression force of 16 kN disintegrated in less than 3 min and showed a friability below 1% when 15-mm punches were used. The tableting process could be done up to 25 and 50 cycles/minute ensuring good quality attributes when 15 and 12-mm punches were used, respectively. All APIs remained inside the limit of ± 5% of drug content till 6 months of storage.Conclusion: A high-quality child-friendly FDC water-dispersible tablet was developed improving the treatment of TB in pediatric.

Ultrafast Gradient Separation with Narrow Open Tubular Liquid Chromatography

Separation speed and resolution are two important figures of merit in chromatography. Often, one gains the speed at the cost of the resolution, and vice versa. Scientists have employed short-packed columns for ultrafast separations but encountered challenges such as limited mobile phase velocity, extra-column effect caused band broadening, and column packing difficulty. We have recently demonstrated ultrahigh resolutions of narrow open tubular liquid chromatography (NOTLC); this allows us to trade some of the resolution for speed. In this work, we explored NOTLC for ultrafast LC separations. We used a 2.7 cm (effective length) narrow open tubular (NOT) column and showed a baseline separation of 6 amino acids in less than 700 ms. Ways to further increase the speed were discussed. Using short narrow open tubular (NOT) columns to perform ultrafast separation we overcame the challenges from using short packed columns. To demonstrate the feasibility of using this ultrafast separation technique for practical applications, we separated complex protein digests; peptides were nicely resolved in ∼1 min.

Simultaneous Determination of Moxifloxacin and Flavoxate by RP-HPLC and Ecofriendly Derivative Spectrophotometry Methods in Formulations

Simple, fast, and precise reversed-phase (RP)-high-performance liquid chromatography (HPLC) and two ecofriendly spectrophotometric methods were established and validated for the simultaneous determination of moxifloxacin HCl (MOX) and flavoxate HCl (FLX) in formulations. Chromatographic methods involve the separation of two analytes using an Agilent Zorbax SB C18 HPLC column (150 mm × 4.6 mm; 5 µm) and a mobile phase consisting of phosphate buffer (50 mM; pH 5): methanol: acetonitrile in a proportion of 50:20:30 v/v, respectively. Valsartan was used as an internal standard. Analytes were monitored by measuring the absorbance of elute at 299 nm for MOX and 250 nm for FLX and valsartan. Two environmentally friendly spectrophotometric (first derivative and ratio first derivative) methods were also developed using water as a solvent. For the derivative spectrophotometric determination of MOX and FLX, a zero-crossing technique was adopted. The wavelengths selected for MOX and FLX were −304.0 nm and −331.8 nm for the first derivative spectrophotometric method and 358.4 nm and −334.1 nm for the ratio first-derivative spectrophotometric method, respectively. All methods were successfully validated, as per the International Conference on Harmonization(ICH) guidelines, and all parameters were well within acceptable ranges. The proposed analytical methods were successfully utilized for the simultaneous estimation of MOX and FLX in formulations.

Design of photoinitiator-functionalized hydrophilic nanogels with uniform size and excellent biocompatibility

Three well-controlled biocompatible hydrophilic nanogels were synthesized, and they can effectively initiate photopolymerization and improve the mechanical properties of polymers.

Simultaneous HPLC assay for pretomanid (PA-824), moxifloxacin and pyrazinamide in an inhaler formulation for drug-resistant tuberculosis

A simple and sensitive reversed phase HPLC method has been developed for the simultaneous quantitation of pretomanid (PA-824), moxifloxacin and pyrazinamide in a combination spray-dried powder formulation for inhalation, without any use of an internal standard. Good resolution of the analytes was achieved on a Luna C18 (2), 150×4.6mm, 5μm, 100Å column using gradient elution with a mobile phase containing methanol and triethylamine phosphate buffer (pH 2.5) at a flow rate of 1.0mL/min in a total run time of 25min. Pyrazinamide, moxifloxacin and pretomanid (PA-824) were detected at wavelengths (retention times) of 269nm (3.80min), 296nm (7.94min) and 330nm (17.46min), respectively. The assay was linear for all analytes in the concentration range 2.5-100μg/mL (correlation coefficients >0.999) with LODs and LLOQs (μg/mL) of pretomanid (PA-824) 0.51 and 1.56, moxifloxacin 0.06 and 0.19 and pyrazinamide 0.35 and 1.06, respectively. Recoveries of the three drugs were 99.6-106.8% with intra- and inter-day precisions (as relative standard deviation) of <7%. The method was successfully applied to an evaluation of content uniformity and freedom from interference by l-leucine of a spray-dried combination powder for inhalation.

Quality evaluation of Panax ginseng roots using a rapid resolution LC-QTOF/MS-based metabolomics approach

Korean ginseng (Panax ginseng C.A. Meyer) contains several types of ginsenosides, which are considered the major active medicinal components of ginseng. The types and quantities of ginsenosides found in ginseng may differ, depending on the location of cultivation, making it necessary to establish a reliable method for distinguishing cultivation locations of ginseng roots. P. ginseng roots produced in different regions of Korea, China, and Japan have been unintentionally confused in herbal markets owing to their complicated plant sources. PCA and PLS-DA using RRLC-QTOF/MS data was able to differentiate between ginsengs cultivated in Korea, China, and Japan. The chemical markers accountable for such variations were identified through a PCA loadings plot, tentatively identified by RRLC-QTOF/MS and partially verified by available reference standards. The classification result can be used to identify P. ginseng origin.

Radiosynthesis and bioimaging of the tuberculosis chemotherapeutics isoniazid, rifampicin and pyrazinamide in baboons

The front-line tuberculosis (TB) chemotherapeutics isoniazid (INH), rifampicin (RIF), and pyrazinamide (PZA) have been labeled with carbon-11 and the biodistribution of each labeled drug has been determined in baboons using positron emission tomography (PET). Each radiosynthesis and formulation has been accomplished in 1 h, using [(11)C]CH(3)I to label RIF and [(11)C]HCN to label INH and PZA. Following iv administration, INH, PZA, RIF, and/or their radiolabeled metabolites clear rapidly from many tissues; however, INH, PZA, and/or their radiolabeled metabolites accumulate in the bladder while RIF and/or its radiolabeled metabolites accumulates in the liver and gall bladder, consistent with the known routes of excretion of the drugs. In addition, the biodistribution data demonstrate that the ability of the three drugs and their radiolabeled metabolites to cross the blood-brain barrier decreases in the order PZA > INH > RIF, although in all cases the estimated drug concentrations are greater than the minimum inhibitory concentration (MIC) values for inhibiting bacterial growth of Mycobacterium tuberculosis (MTB). The pharmacokinetic (PK) and drug distribution data have important implications for treatment of disseminated TB in the brain and pave the way for imaging the distribution of the pathogen in vivo.

Development and validation of UPLC method for quality control of Curcuma longa Linn.: Fast simultaneous quantitation of three curcuminoids

A new reversed phase ultra performance liquid chromatography (UPLC) method was developed for the rapid quantification of three curcuminoids (curcumin (C), desmethoxycurcumin (DMC) and bisdesmethoxycurcumin (BDMC)) in Curcuma longa Linn. (C. longa) using a Waters BEH Shield RP C(18), 2.1 mm x 100 mm, 1.7 microm column. The runtime was 2 min. The influence of column temperature and mobile phase on resolution was investigated. The method was validated according to the ICH guideline for validation of analytical procedures with respect to precision, accuracy, and linearity. The limits of detection were 40.66, 49.38 and 29.28 pg for C, DMC and BDMC, respectively. Limits of quantitation for C, DMC and BDMC, were 134.18, 164.44 and 97.50 pg, respectively. Linear range was from 3.28 to 46.08 microg/ml. The mean+/-SD percent recoveries of curcuminoids were 99.47+/-1.66, 99.50+/-1.99 and 97.77+/-2.37 of C, DMC and BDMC, respectively. Comparison of system performance with conventional HPLC was made with respect to analysis time, efficiency and sensitivity. The proposed method was found to be reproducible and convenient for quantitative analysis of three curcuminoids in C. longa. This work provided some references for quality control of C. longa.