Different Eco-Friendly Spectrophotometric Approaches Including Direct and Manipulations of Zero and Ratio Spectra for Simultaneous Determination of Novel Nasal Spray Combination Used in Seasonal Allergic Rhinitis.

BACKGROUND: The presentation of rhinitis has drawn increasing attention in recent years due to the possibility of overlap or confusion between allergic rhinitis symptoms and those of COVID-19. Azelastine hydrochloride (AZH) and mometasone furoate (MOF) are two of the most efficient combinations for enhancing the symptoms of seasonal allergic rhinitis. OBJECTIVE: This work concerns applying and validating different accurate and simple spectrophotometric approaches for simultaneous quantification of the binary mixture of AZH and MOF in raw material, laboratory-prepared mixtures, and pharmaceutical preparation. Moreover, assessment of the environmental impact of the applied approaches on the environment was also a key goal of this study. METHODS: AZH was determined using the direct spectrophotometric (D0) method, while four reliable spectrophotometric approaches namely, induced dual wavelength (IDW), ratio subtraction (RS), ratio difference (RD), and ratio derivative (1DD) were used for MOF determination. RESULTS: The methods were validated in line with the International Conference of Harmonization standards. In the AZH range of (5-56 µg/mL) and MOF range of (2-20 µg/mL), the linearity of the proposed approaches was investigated with high accuracy findings. There were no significant differences between the obtained results and those of the reported method when compared statistically. Furthermore, the applied spectrophotometric methods were deemed to be eco-friendly according to Green Analytical Procedure Index (GAPI) and Analytical Greenness Calculator (AGREE) assessment metrics. CONCLUSIONS: The applied spectrophotometric methods are simpler, more eco-friendly, and take a shorter time to precisely estimate many measurements compared to the only reported chromatographic analysis. HIGHLIGHTS: Neither publications of novel spectrophotometric methods nor reported green ones have been available for simultaneous determination of the binary mixture of AZH and MOF, so this work has a great significance and novelty in the area of pharmaceutical analysis.

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.

Development of green micellar HPLC-DAD method for simultaneous determination of some sulbactam combinations used in COVID-19 regimen.

In a new attempt to separate some sulbactam combinations by green chemical method we came up with this research in which an ecofriendly, green, sustainable and selective method was established for separation of four antibiotics, namely, cefoperazone (CFP), cefixime (CFX), ampicillin (AMP) and sulbactam (SLB). No organic solvents were used in the composition of the mobile phase as it was replaced by mixing two surfactants together, sodium dodecyl sulfate (SDS) and polyoxyethylene-23-lauryl ether (Brij-35). Effect of varying the concentrations of the two surfactants on chromatographic separation was studied. Optimum separation was maintained using a mobile phase consisting of 0.01 mol/L SDS, 0.03 mol/L Brij-35, 0.4% Tri-ethylamine (TEA) and pH of 2.8 adjusted by using 1 M ortho-phosphoric acid on reversed phase Isère C18 BDS column with temperature of 40 °C at flow rate 1 mL/min, wavelength 215 nm, and the total run time was 6 min. Validation of the proposed method has been made according International Conference of Harmonization (ICH) guidelines at linearity range of 10-200 µg mL-1 for all drugs under study, high accuracy results (recovery range 98.39-100.35%). and the variation coefficient (RSD) of the points on the calibration curve was ranged from (0.1-1.7%) indicating precise method. The LOQ was (6.09 µg mL-1) for CFP, (6.07 µg mL-1) for CFX, (3.85 µg mL-1) for AMP and (7.20 µg mL-1) for SLB. Successful applications were made on marketed dosage forms with recovery range of (100.16-102.25%) and RSD of (0.03-1.88%). The method was verified on the Green Analytical Procedure Index (GAPI) and Analytical Greenness metric approach (AGREE) and it was found to be an excellent green alternative method.

Evaluating the impact of COVID-19 on traffic congestion and safety skills using structural equation modeling (SEM) and Auto-Regressive Integrated Moving Average (ARIMA).

The current work presented a comparative analysis of traffic demand and safety skills before and after control measures during the COVID-19 epidemic, acquired time-series change data curves, and constructed a prediction model after determining the trend of traffic demand over time. From a data analysis perspective, the paper draws some interesting conclusions about long span, coarse sampling studies. In terms of the study population, the paper did focus on the specificity of the global epidemic. Kuwait was selected as a case study. Traffic demand analysis was conducted using a Structural Equation Model (SEM), Auto-Regressive Integrated Moving Average (ARIMA), and safety skills questionnaire along with flow charts and demographic variables. These methods were utilized to study the impact of COVID-19 on traffic congestion and safety skills as well as to forecast the future traffic volumes. Results showed that traffic congestion had a significant reduction during COVID-19 as a result of the preventive safety measures taken to control the spread of the virus. Such reduced traffic volume was associated with a decrease in traffic violations and an increase in the safety skills and PM skills of drivers.

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.

Green Spectrophotometric Determination of Two Cephalosporin Drugs Used in COVID-19 Regimen Through Silver Nanoparticle Synthesis.

BACKGROUND: Cefixime trihydrate (CFX) and cefuroxime axetil (CFU) are antibacterial drugs. They are widely used in the treatment of bacterial infection and recently in COVID-19 treatment. OBJECTIVE: In this article, the two antibacterial drugs, CFX and CFU, were determined by a new simple, sensitive, effective, and green spectrophotometric method via reaction with silver nitrate (AgNO3). METHODS: The reaction was based on reduction of AgNO3 by the cited drugs to silver nanoparticles (Ag-NPs) in the presence of polyvinylpyrrolidine (PVP) as stabilizing agent. Very intense surface plasmon resonance peaks were obtained at 435 nm for CFX and CFU that allow quantitative determination of the drugs. RESULTS: The calibration curves were linear with concentration ranges of 0.2-1.4 µg/mL and 0.3-2.1 µg/mL for CFX and CFU, respectively. Validation of the proposed method has been done according to ICH (International Conference of Harmonization) guidelines; the method was verified on the Green Analytical Procedure Index and Analytical Greenness metric approach (AGREE) in regard to its greenness and was found to be an excellent green alternative method. CONCLUSION: A very sensitive and green spectrophotometric method was developed for determination of CFX and CFU in pure and dosage form. HIGHLIGHT: The developed method not previously reported for simultaneous determination of CFX and CFU.

A green spectrophotometric method for the simultaneous determination of nasal binary mixture used in respiratory diseases: Applying isosbestic point and chemometric approaches as a resolving tool, greenness evaluation.

Nasal drug combination is a very useful therapy for elevating the symptoms of various respiratory diseases as seasonal allergic rhinitis and infectious respiratory illness as pandemic COVID-19. One of best combination is Fluticasone propionate (FLU) and Azelastine (AZE). In this study, different UV spectrophotometric and chemometric methods have been applied for quantitative analysis of FLU and AZE without previous separation in their pure form, laboratory prepared mixture and pharmaceutical dosage form. Absorbance subtraction (AS) and Amplitude modulation (AM) spectrophotometric methods have been applied for the simultaneous determination of the cited drugs. Besides, three well-known chemometric techniques; namely, classical least squares (CLS), partial least square (PLS), and principal component regression (PCR) have been applied for the simultaneous analysis of both drugs by using spectrophotometric data. To be friendly to the environment, the greenness of the proposed methods was taken into consideration and evaluation of the analytical methods' greenness was done using two green analytical chemistry metrics known as, Analytical Greenness Calculator and an eco-scale scoring method. They indicated that the methods were environmentally friendly in relation to numerous approaches like instrument, reagents, and safety of waste. Analyzing laboratory prepared mixtures including different quantities of FLU and AZE, as well as their marketed dose form, was used to assess the selectivity of the applied methods. The validity of the developed methods was investigated by applying the standard addition technique. The resulting data were statistically compared to those obtained by the official or reported HPLC methods for FLU and AZE, which revealed no significant difference in accuracy and precision at p = 0.05.

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.

Voltammetric Determination of Sulfaclozine Sodium at Sephadex-modified Carbon Paste Electrode.

The electrochemical behavior of Sulfaclozine Sodium (SLC) was studied at a bare and sephadex-modified carbon paste electrodes by cyclic voltammetry and square wave voltammetry. The cyclic voltammetry (CV) showed a well-defined irreversible oxidation peak at 0.94 V in Britton- Robinson buffer pH 7.0. The strong affinity of SLC to sephadex allowed accumulation of SLC at the surface of electrode and thus higher electrochemical sensitivity to SLC. The influence of sephadex loading, the pH of the solution and the scan rate on the peak current was studied. A linear calibration curve covering the concentration range from 0.005 to 1 mM was obtained using SWV. The method was successfully applied for the determination of SLC in the veterinary pharmaceutical formulations with satisfactory accuracy and precision.

Silver Nanoparticles Synthesis for Sensitive Spectrophotometric Determination of Sofosbuvir, Lamivudine, and Ritonavir in Pure Forms and Pharmaceutical Dosage Forms.

BACKGROUND: Silver nanoparticles synthesis is now widely applicable as a method for sensitive spectrophotometric determination of many pharmaceuticals. OBJECTIVE: A highly sensitive, cheap, green, nonextractive, and accurate spectrophotometric method was developed for the determination of three important antiviral drugs. METHODS: The method depends on the formation of silver nanoparticles as a result of the redox reaction between antiviral drugs as a reducing agent and AgNO3 as an oxidizing agent in presence of polyvinyl pyrrolidone as a stabilizing agent. The UV absorbance of the resulted golden yellow silver nanoparticles can be easily measured at 421 nm for Sofosbuvir (SFS) and Ritonavir (RIT) and at 425 nm for Lamivudine (LAM). RESULTS: The LODs were 23.5, 30, and 21.5 nm/mL for SFS, LAM, and RIT, respectively. The LOQs were 70.5, 90, and 64.6 nm/mL for SFS, LAM, and RIT, respectively. The method was validated according to International Conference on Harmonization guidelines, and it was successively applied for the determination of the studied drugs in their different pharmaceutical dosage forms and gave excellent percent of recovery. The results showed excellent agreement with the reported method with respect to precision and accuracy. CONCLUSIONS: Being simple, fast, robust, and economic, this method is eligible for use in the routine work in pharmaceutical quality control laboratories. HIGHLIGHTS: A sensitive and economic spectrophotometric method was developed and validated for quantitative determination of SFS, LAM, and RIT. The method was validated and applied for determination of the studied drugs in their different formulations. The method used water as the main solvent, so our proposed method is considered environmentally friendly.

Development and validation of eco-friendly micellar-HPLC and HPTLC-densitometry methods for the simultaneous determination of paritaprevir, ritonavir and ombitasvir in pharmaceutical dosage forms.

Ombitasvir, ritonavir and paritaprevir are three recently discovered directly acting antiviral drugs (DAADs) used in combined single dose tablet dosage form for treatment of hepatitis-C viral infections (HCV). The methods of analysis followed by quality control and research laboratories are required to be economic and fast; however, these methods can also produce huge amounts of chemical waste. In this study two fast, economic and green HPLC and HPTLC methods were validated for the simultaneous determination of the three drugs. For HPLC, isocratic elution used a mixture of micellar aqueous mobile phase consisting of (0.15 M sodium lauryl sulfate and 0.01 M sodium dihydrogen phosphate, pH 6.2) and ethanol (56:44). Elution was done on RP-C18 Kinetix® column (5 µm, 150 mm × 4.6 mm ID) at flow 1 mL min-1 and 254 nm UV-detector. HPTLC separations were performed on Merck® (20 cm × 10 cm) aluminum HPTLC plates coated with silica gel 60F254 using a mobile phase, Methylene chloride: methanol: ethyl acetate: ammonia (25%), (5:1:3:1, v/v/v/v) respectively. The calibration curves were linear across ranges of 3-100 µg mL-1 and 0.1-2 µg/spot for both HPLC and HPTLC methods, respectively. The two methods were applied successfully for the determination of the three drugs under study in their combined tablets dosage forms.

Development of a highly sensitive high-performance thin-layer chromatography method for the screening and simultaneous determination of sofosbuvir, daclatasvir, and ledipasvir in their pure forms and their different pharmaceutical formulations.

The combination of sofosbuvir and daclatasvir or sofosbuvir and ledipasvir is now widely used as an ideal treatment for hepatitis C virus infection. For this purpose, a simple, sensitive, accurate, economic, and precise high-performance thin-layer chromatography was developed and validated for the determination of sofosbuvir, daclatasvir, and ledipasvir in their pure form as well as their different pharmaceutical products. The method used Merck high-performance thin-layer chromatography aluminum plates precoated with silica gel 60 F254 as a stationary phase and mobile phase consisting of methylene chloride/methanol/ethyl acetate/ammonia (25%) (6:1:4:1, v/v/v/v). This system was found to give compact symmetric peaks of sofosbuvir, daclatasvir, and ledipasvir with retardation factors of 0.27 ± 0.01, 0.50 ± 0.007, and 0.68 ± 0.008, respectively. The densitometric scanner was set at 275 nm using a deuterium lamp. The calibration curves were linear over the range of 100-3000 ng/spot for sofosbuvir, and daclatasvir, and range of 50-3000 ng/spot for ledipasvir. The detection limits were 22.5, 31.90, and 15.80 for sofosbuvir, daclatasvir, and ledipasvir. The quantitation limits were 67.50, 95.60, and 47.50 for sofosbuvir, daclatasvir, and ledipasvir. The proposed method was validated according to International Conference on Harmonization (ICH) guidelines and the results were acceptable.

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.

Quantitative HPLC analysis of mebeverine, mesalazine, sulphasalazine and dispersible aspirin stored in a Venalink monitored dosage system with co-prescribed medicines.

An HPLC method for the quantitative analysis of mebeverine HCl, 5-aminosalicylic acid (5-ASA), sulphasalazine and dispersible aspirin has been developed and then applied to these specific medicines when stored, with other medications, in Venalink blister packs (monitored dosage system) for periods of up to 35 days. Chromatographic separation was achieved on a reversed-phase C(12) column with an isocratic mixture of methanol, water and acetic acid as the mobile phase. The method was validated regarding: accuracy, precision, detection limits, quantification limits, specificity and robustness.

Utility of NBD-Cl for the spectrophotometric determination of some skeletal muscle relaxant and antihistaminic drugs.

A simple, accurate, precise and sensitive colorimetric method for the determination of some skeletal muscle relaxant drugs, namely orphenadrine citrate (I), baclofen (II), antihistaminic drugs as acrivastine (III) and fexofenadine hydrochloride (IV) is described. This method is based on the formation of charge transfer complex with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) in non-aqueous medium. The orange color products were measured at 472, 465, 475 and 469 nm for drugs I, II, III and IV, respectively. The optimization of various experimental conditions was described. Beer's Law was obeyed in the range (2.5-17.5), (5-70), (2.5-25) and (10-50)microg/ml for drugs I, II, III and IV, respectively. The molar absorptivity (epsilon), sandell sensitivity, detection((LOD)) and quantitation limits((LOQ)) are calculated. The procedure was favorably applied for determination of certain pharmaceutical dosage forms containing the studied drugs. The obtained results were compared with the official and reported methods. There were no significant differences between proposed, reported and the official methods.