Exciting Advances in Sustainable Spectrophotometric Micro-Quantitation of an Innovative Painkiller "Tramadol and Celecoxib" Mixture in the Presence of a Toxic Impurity, Promoting Greenness and Whiteness Studies.

BACKGROUND: Tramadol (TRM) and celecoxib (CLX) form a novel mixture that helps relieve acute pain when other painkillers have no action. It is also reported that these drugs, TRM and CLX, are used to control COVID-19 symptoms. OBJECTIVE: The current work highlights three important pillars of modern pharmaceutical analysis, which are as follows; impurity profiling, greenness/whiteness studies and simplicity accompanied by sensitivity. Since 4-methyl acetophenone inhibits the human carbonyl reductase enzyme (type I) and since this compound may pose a health risk, it is crucial to regulate its concentration in all dosage forms of CLX. METHODS: Two simple and green spectrophotometric methods were developed, namely third derivative (D3) and Fourier self- deconvulation (FSD), for resolving severely overlapped spectra of TRM and CLX in the presence of 4-methyl acetophenone (4-MAP) as a process-related impurity in their novel tablet combination. RESULTS: The two approaches showed acceptable linearity with an excellent correlation coefficient. In both methods, TRM was measured when CLX and 4-methyl acetophenone were zero-crossing. The same procedure was applied for measuring CLX and its process-related impurity 4-MAP. CONCLUSION: The methodologies developed were thoroughly validated in compliance with ICH (International Council on Harmonisation) guidelines. Student t- and F-tests revealed no statistically significant variation among the current methods and the reported method. HIGHLIGHTS: No spectrophotometric methods have been published previously for the simultaneous analysis of TRM and CLX along with 4-MAP. As a result, the newly developed spectrophotometric approaches have great relevance and originality in the field of pharmaceutical analysis.

HPLC-DAD technique for the quantification of a recently approved anti-diabetic triple combination along with two toxic official impurities: Toxicity confirmation aided by molecular docking application.

BACKGROUND: Gliflozins and gliptins are two distinct groups of pharmacological drugs that reduce blood glucose levels in individuals with type II diabetes in various ways that may perform their functions harmoniously. Trijardy® tablet, which contains empagliflozin, linagliptin, and metformin, was recently approved. The scientific database does not yet have a method that is sensitive enough to quantify the aforementioned medications in the presence of metformin official toxic impurities melamine and cyanoguanidine. Molecular docking modeling was utilized in this work to further prove the toxicity of melamine. METHODS: The five analytes listed before were quantified using RP-HPLC-diode array detector and a Zorbax® C8 column (4.6 × 250 mm, 5 µm) with isocratic mobile phase composed of acetonitrile and 0.05 M potassium dihydrogen phosphate buffer, which had been treated by ?-phosphoric acid to restore a pH of 4.0 (90:10, v/v) at a flow rate of 1.2 mL/min and the eluted peaks were scanned at 250 nm. CONCLUSION: The utilization of the simplest isocratic elution mode give the current technique a significant time-and cost-saving benefit. The current method can quantify the triple therapy agents in the presence of each other as well as with two official toxic impurities of metformin in one short analytical run.

Manipulation and Processing of Spectral Signals for the Assay of the Newly Authorized Mixture of Bupivacaine/Meloxicam Using Fully Green Solvents and a Comparative Green Evaluation Supporting the Greenness and Sustainability of the Developed Smart Spectrophotometric Methods.

BACKGROUND: The bupivacaine (BVC)/meloxicam (MLX) combination is the first extended-release dual-acting local anesthetic (DALA) that provides 72 h of postoperative pain relief. It reduces opioid use after surgery and manages pain better than BVC alone over 72 h, and overcomes surgical site inflammation with a new synergistic mode of action that combines BVC with a low dosage of MLX. OBJECTIVE: In today's pharmaceutical research, we take great care to only use non-toxic solvents that pose no threat to either humans or the environment. This work determines BVC and MLX simultaneously, utilizing water and 0.1 M HCl in water as solvents. Moreover, the eco-friendliness of the specified solvents and the whole method development steps was evaluated based on how user-friendly they were using four standard methodologies. METHODS: The developed spectrophotometric methods depended on either zero-order, derivative, or ratio spectra that only required simple mathematical handling. The current techniques include dual wavelength (DW), Fourier self-deconvolution (FSD), first derivative (D1), ratio difference (RD), and first ratio derivative (DD1). RESULTS: Linearity was confirmed over a concentration range of 50-700 µg/mL for BVC and 1-10 µg/mL for MLX. For BVC and MLX, the LOQs were 26.85-41.33 µg/mL and 0.21-0.95 µg/mL, while the LODs were 8.86-13.64 µg/mL and 0.06-0.31 µg/mL, respectively. For the full validation of the proposed methods, ICH (international conference on harmonization) criteria were followed. CONCLUSION: Current methods have the advantage of sticking to the basis of zero-order, derivative, or ratio spectra and needing just the barest minimum of data processing: no complex software, lengthy stages, or transformations are needed. HIGHLIGHTS: No spectrophotometric methods have been published for the simultaneous analysis of BVC and MLX. As a result, the newly developed spectrophotometric approaches have great relevance and originality in the field of pharmaceutical analysis.

Green micelle and complex inclusion enhance synchronous spectrofluorimetric quantification of a novel analgesic combination: Tramadol and celecoxib in tablet dosage form and spiked human plasma.

This work offers for the first time an optimized, highly sensitive, simple, and accurate synchronized spectrofluorimetric technique for the simultaneous measurement of tramadol and celecoxib in powder form, their combined multimodal tablet, and finally spiked human plasma samples. Tramadol and celecoxib were recently released as a new drug combination to alleviate intense, sudden pain when other pain medications had failed. The technique entailed taking measurements of the fluorescence amplitudes of the synchronized spectra at Δλ = 100 nm. Excitation was made at 220 nm and 264 nm, whereas the emission points were 282 nm and 368 nm for tramadol and celecoxib, respectively. This technique offers linearity of 40-400 ng/ml and 100-2000 ng/ml for tramadol and celecoxib, respectively. Complex formation between the cited medications with the surfactant sodium dodecyl sulphate enhanced the fluorescence intensity and other control parameters. Tramadol and celecoxib were both determined in spiked human plasma using the current technique with marked percentage recoveries of 98.63 ± 6.30% and 99.32 ± 6.67%, respectively. Last, the research was extended to check the greenness profile of the finally optimized method and the results revealed excellent eco-friendliness. Three greenness assessment tools were used including Eco-scale, the Green Analytical Procedure Index tool, and the AGREE calculator. Sustainable development, economic feasibility, and environmental soundness were all considered throughout the development of the present technique. The approach was validated in accordance with the requirements provided by the International Council for Harmonization.

Severe bilateral ankyloblepharon filiforme adnatum.

We present a case of bilateral ankyloblepharon filiforme adnatum in 1-day-old girl and describe our surgical approach. The bands connecting the upper and lower eyelids of both eyes were severed using blunt scissors. Point bleeding at the cut bands stopped in 1-2 minutes, without the need for cauterization or compression. The patient was able to open her eyes shortly after the procedure, as she woke up from anesthesia. Examination under general anesthesia showed normal eye examination appropriate for age. Postoperatively, the patient maintained open palpebral fissures. Visual development over 3 years' follow-up was normal.

Core-shell particles and monolithic columns; tools for simultaneous LC analysis of avanafil, sildenafil, apomorphine, trazodone, yohimbine, tramadol and dapoxetine in pharmaceutical dosage forms, counterfeit products and human plasma.

By 2025, it's estimated that 322 million males worldwide will suffer from sexual disorders. This can give an estimation for the size of the pharmaceutical and counterfeit products industry for the next few years. Meanwhile, green analytical chemistry forced itself to decrease the massive environmental pollution and hence new analytical methodologies are needed to replace the old ones that consume large amounts of hazardous solvents. In this research, two new methods were validated for determination of seven recognized drugs used in treatment of male impotence, premature ejaculation as well as enhancing sexual libido by HPLC on RP-C18 core-shell particulate and monolithic columns. The study was extended to compare the capabilities of those stationary phases to accommodate greener chromatography concepts without loss of efficiency. Both morphologies shortened the analysis time relative to the previously reported conventional HPLC methods by different approaches. Core-shell particles had higher efficiency in terms of theoretical plates' number and enhanced resolution power which enabled lower detection limits. However, the monolithic column had lower column backpressure which enabled the use of ethanol as a greener alternative solvent at even higher flow rates. The methods were finally applied successfully for the determination of drugs under study in pharmaceutical dosage forms, counterfeit products and in human plasma.

Performance Comparison Between Monolithic, Core-Shell, and Totally Porous Particulate Columns for Application in Greener and Faster Chromatography.

Background: The introduction of monolithic rods and core-shell particles as new morphologies of packing materials different from the conventional totally porous particles resulted in a leap forward for performance in LC. Meanwhile, environmental safety has become increasingly important in many areas, especially in industry and research laboratories. Objective: This study compared the efficiencies of commercially available columns of different lengths and diameters when greener chromatographic conditions were utilized. The main purpose of this study is to help practitioners select the most appropriate stationary phase for faster and greener analysis. Methods: The three types of stationary phases were compared in terms of separation efficiency, number of theoretical plates, peak shape, selectivity, resolution, analysis time, mobile phase consideration, and permeability using six drug molecules. Results: Results indicated that core-shell and monolithic stationary phases had superiority over the conventional totally porous particles in terms of efficiency and speed of analysis. Monolithic rods had lower column backpressure and higher permeability, so they are more suitable for higher mobile phase flow rates and viscosities. However, core-shell particles provided enhanced peak shapes and number of theoretical plates. Conclusions: The choice will depend on the main purpose of analysis and the composition of the mobile phase. Compromise must be made to obtain the best trade-off between separation efficiency and analysis speed. Highlights: This study is the first to consider green chromatography concepts for the selection of the best stationary phase of new morphologies.

Comparison between core-shell and totally porous particle stationary phases for fast and green LC determination of five hepatitis-C antiviral drugs.

The performances of core-shell 2.7 µm and fully porous sub-2 µm particles packed in narrow diameter columns were compared under the same chromatographic conditions. The stationary phases were compared for fast separation and determination of five new antiviral drugs; daclatasvir, sofosbuvir, velpatasvir, simeprevir, and ledipasvir. The gradient elution was done using ethanol as green organic modifier, which is more environmentally friendly. Although both columns provided very good resolution of the five drugs, core-shell particles had proven to be of better efficiency. Under gradient elution conditions, core-shell particles exhibited faster elution, better peak shape, and enhanced resolution adding to lower system backpressure. The column backpressure on sub-2 µm particles was more than twice that on core-shell particles. This gives a chance to use conventional high-performance liquid chromatography conditions without needing special instrumentation as that required for ultra-high performance liquid chromatography. The method was validated for determination of the five drugs by gradient elution using mobile phase composed of organic modifier ethanol and aqueous part containing 0.75 g sodium octane sufonate and 3.0 g sodium dihydrogen phosphate per liter at pH of 6.15. Detection was done using UV-detector set at 210 nm. The linearity, accuracy, and precision were found very good within the concentration range of 2-200 µg/mL.

High performance liquid chromatography for simultaneous determination of xipamide, triamterene and hydrochlorothiazide in bulk drug samples and dosage forms.

A novel, simple and robust high-performance liquid chromatography (HPLC) method was developed and validated for simultaneous determination of xipamide (XIP), triamterene (TRI) and hydrochlorothiazide (HCT) in their bulk powders and dosage forms. Chromatographic separation was carried out in less than two minutes. The separation was performed on a RP C-18 stationary phase with an isocratic elution system consisting of 0.03 mol L(-1) orthophosphoric acid (pH 2.3) and acetonitrile (ACN) as the mobile phase in the ratio of 50:50, at 2.0 mL min(-1) flow rate at room temperature. Detection was performed at 220 nm. Validation was performed concerning system suitability, limits of detection and quantitation, accuracy, precision, linearity and robustness. Calibration curves were rectilinear over the range of 0.195-100 µg mL(-1) for all the drugs studied. Recovery values were 99.9, 99.6 and 99.0 % for XIP, TRI and HCT, respectively. The method was applied to simultaneous determination of the studied analytes in their pharmaceutical dosage forms.

Chromatographic analysis of some drugs employed in erectile dysfunction therapy: qualitative and quantitative studies using calixarene stationary phase.

In this study, the effect of change in chromatographic process variables on the retention behavior of four drugs employed in erectile dysfunction therapy on a calixarene stationary phase is described. Three of these drugs are known to treat erectile dysfunction, namely, sildenafil citrate, tadalafil, and apomorphine hydrochloride, and one drug that is used as opioid analgesic, tramadol hydrochloride, which is quiet widely misused to treat premature ejaculation. The results indicate the importance of considering the structure and pKa values of drugs to be separated along with mobile phase composition. A new optimized, rapid, and accurate liquid chromatography method is also established for simultaneous determination of sildenafil citrate, tadalafil, and apomorphine hydrochloride in pharmaceutical preparations and bulk powders. The chromatographic separation of the three pharmaceuticals was achieved on a calixarene column in less than 10 min using a binary mobile phase of 35% acetonitrile and 65% 50 mM sodium perchlorate pH2.5 at 1 mL/min flow rate. The method was validated for system efficiency, linearity, accuracy, precision, limits of detection and quantitation, specificity, stability, and robustness. Statistical analysis proved that the method enabled reproducible and selective quantification of all three analytes in bulk drugs and in pharmaceutical preparations.

Development and validation of a rapid stability indicating HPLC-method using monolithic stationary phase and two spectrophotometric methods for determination of antihistaminic acrivastine in capsules.

Simple, rapid and accurate high performance liquid chromatographic (HPLC) and spectrophotometric methods are described for determination of antihistaminic acrivastine in capsules. The first method (method A) is based on accurate, sensitive and stability indicating chromatographic separation method. Chromolith® Performance RP-18e column, a relatively new packing material consisting of monolithic rods of highly porous silica, was used as stationary phase applying isocratic binary mobile phase of ACN and 25 mM NaH2PO4 pH 4.0 in the ratio of 22.5:77.5 at flow rate of 5.0 mL/min and 40°C. A diode array detector was used at 254 nm for detection. The elution time of acrivastine was found to be 2.080±0.032. The second and third methods (methods B and C) are based on the oxidation of acrivastine with excess N-bromosuccinimide (NBS) and determination of the unconsumed NBS with, metol-sulphanilic acid (λmax: 520 nm) or amaranth dye (λmax: 530 nm). The reacted oxidant corresponds to the drug content. Beer's law is obeyed over the concentration range 1.563-50, 2.0-20 and 1.0-10 µg mL(-1) for methods A, B and C, respectively. The limits of detection and quantitation were 0.40, 0.292 and 0.113 µg mL(-1) and 0.782, 0.973 and 0.376 µg mL(-1) for methods A, B and C, respectively. The HPLC method was validated for system suitability, linearity, precision, limits of detection and quantitation, specificity, stability and robustness. Stability tests were done through exposure of the analyte solution for four different stress conditions and the results indicate no interference of degradants with HPLC-method. The proposed methods was favorably applied for determination of acrivastine in capsules formulation. Statistical comparison of the obtained results from the analysis of the studied drug to those of the reported method using t- and F-tests showed no significant difference between them.

Spectrophotometric and stability-indicating high-performance liquid chromatographic determinations of terbutaline sulfate.

Spectrophotometric and stability-indicating HPLC procedures are described for determination of terbutaline sulfate in bulk powder and dosage form. The first procedure is based on diazo coupling of the phenolic groups of terbutaline sulfate with fast red B salt in the presence of sodium hydroxide. The colored compound developed in alkaline medium was measured at 475 nm. Different variables affecting the reaction were studied. Beer's Law is obeyed in the concentration range of 1-6 microg/mL. In the HPLC procedure, the separation was carried out on a Caltrex AIII column, a relatively new packing material consisting of silica-bonded calix[8]arene, using an isocratic binary mobile phase, acetonitrile-ammonium acetate (50 + 50, v/v), at pH 6.2. A diode array detector was used at 280 nm. The method was validated for system suitability, linearity, precision, LOD, LOQ, specificity, stability, and robustness. The LOD and LOQ were 0.196 and 0.781 microg/mL, respectively. The recovery values of this method were between 98 and 102%, and the reproducibility was within 0.92%. Statistical comparison of the results obtained from the analysis of the studied drug to those of the official British Pharmacopoeia (2007) method using t- and F-tests showed no significant difference between them.

Spectophotometric methods for determination of cefdinir in pharmaceutical formulations via derivatization with 1,2-naphthoquinone-4-sulfonate and 4-chloro-7-nitrobenzo-2-oxa-1, 3-diazole.

Two new simple, sensitive, accurate, and precise spectrophotometric methods have been developed and validated for the determination of cefdinir (CFD) in bulk drug and in its pharmaceutical formulations. The first method was based on the reaction of CFD with 1, 2- napthaquinone-4- sulfonic acid sodium (NQS) in an alkaline medium (pH 11) to form an orange-coloured product that was measured at 490 nm. The second method depends on hydrolysis of CFD using 0.5 M NaOH at 100 °C and subsequent reaction of the formed sulfide ions with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) to form a yellow-coloured chromogen measured at 390 nm. Different variables affecting the reactions of CFD with both NQS and NBD-Cl (e.g. NaOH concentration, hydrolysis time, NQS or NBD-Cl concentration and diluting solvent) were studied and optimized. Under optimum conditions, good linear relationships with good correlation coefficients (0.9990-0.9999) were found in the range of 10-80 and 5.0-30 µg ml(-1) for NQS and NBD-Cl, respectively. The limits of assay detection and quantitation ranged from 1.097 and 0.280 and 3.656 and 0.934 µg ml(-1) for NQS and NBD-Cl, respectively. The accuracy and precision of the proposed methods were satisfactory. The proposed method is simple, rapid, precise and convenient and was successfully applied for analysis of CFD in its pharmaceutical formulations and the recovery percentages ranged from 99.25 to 100.20%.

Effect of chromatographic conditions on liquid chromatographic chiral separation of terbutaline and salbutamol on Chirobiotic V column.

In this study, a method for enantioseparation of terbutaline and salbutamol was established using Chirobiotic V column as a stationary phase. Polar ionic mode applying mobile phase containing ammonium nitrate in 100% ethanol, pH 5.1 was found to give the best separation. The salt concentration in the mobile phase and pH value were found to be the most important chromatographic factors affecting separation. Separation of enantiomers of these two basic analytes was complete in less than 10 min without applying ammonium trifluoroacetate (ATFA) or triethylamine (TEA) salts.

Comparison of the chromatographic behavior of tricyclic neuroleptics on calixarene-bonded, monolithic and conventional RP-HPLC columns.

The effect of different chromatographic conditions, such as buffer concentration and type of organic modifier, on the retention behavior of nine tricyclic neuroleptics on three different RP-HPLC columns was investigated. Two recently developed columns, calixarene-bonded (CALTREX) AIII) and monolithic (Chromolith) Performance RP-18e) columns, were compared with a conventional RP-C18 HPLC column (LiChrospher). The results showed how the mobile phase conditions had different effects on the analyte retention on these three columns. For example, the elution order of some analytes and the initiation of separation of the geometric isomers of the three analytes--which have E/Z-isomers (cis/trans-isomers)--could be altered by changing the conditions and the column type. Under identical conditions, a calixarene-bonded phase was the best for this separation, a monolithic phase gave comparable results and the conventional RP-column was the least effective. Concerning the geometric isomers separation, the Chromolith Performance RP-18e was superior.

Effect of chaotropic mobile phase additives on retention behaviour of beta-blockers on various reversed-phase high-performance liquid chromatography columns.

In this study the effect of type and concentration of chaotropic counter anion in buffered mobile phase on retention behaviour of some beta-blockers was studied. Two types of anions (perchlorate, dihydrogen phosphate) were examined under different concentrations. Further different pH-values for each anion were used to investigate the effect of pH changes on chaotropic behaviour of these anions. The role of organic modifier (methanol, acetonitrile) type was also considered. All these parameters were studied for three different RP-columns (calixarene modified silica gel, monolithic RP-column and a conventional RP-column). The results indicate that all studied factors affected the chaotropic behaviour of the tested anions. Also the type of the used stationary phase has found to play an important role in retention behaviour of beta-blockers.

Retention behaviour of beta-blockers in HPLC using a monolithic column.

The chromatographic behaviour of a new HPLC-stationary phase (Chromolith RP-18e) is described for separation of beta-blockers. The effects of the different chromatographic conditions (buffer system, pH value, content of organic modifier, injection volume and flow rate) on the separation behaviour were studied. At higher flow rates the peaks seemed to be more symmetrical than at lower flow rates. The use of buffer or salt in the mobile phase for this separation is found to be very essential and the counter-anion type of this buffer or salt significantly affected the retention behaviour of beta-blockers while the cation type did not play the same important role.