Derivative UV Spectrophotometry Research Articles

Determination of levofloxacin, norfloxacin, and moxifloxacin in pharmaceutical dosage form or individually using derivative UV spectrophotometry

PurposeIn this study, first, second, third, and fourth-order derivative spectrophotometric methods utilizing the peak—zero (P—O) and peak-peak (P—P) techniques of measurement were developed for the determination of levofloxacin, norfloxacin, and moxifloxacin. These methods were applied to their combined pharmaceutical dosage form or individually for levofloxacin, norfloxacin, and moxifloxacin.MethodsLinearity was established in the concentration range of 2–20 µg/mL. The procedures are simple, quick, and precise. The developed methods are sensitive, accurate, and cost-effective, demonstrating excellent correlation coefficients (R2 = 0.9998) and mean recovery values ranging from 99.20% to 100.08%, indicating a high level of precision.ResultsThe developed approach was effectively employed to determine the levofloxacin, norfloxacin, and moxifloxacin content in commercially available pharmaceutical dosages.ConclusionsStatistical analysis and recovery tests confirmed the method's linearity and accuracy. The results suggest that this method can be utilized for routine analysis in both bulk and commercial formulations. The simplicity, accuracy, and cost-effectiveness of the developed methods make them valuable for pharmaceutical analysis.

What to consider for successful administration of oral liquids via enteral feeding tubes? a case study with paediatric ibuprofen suspensions

Administration of medications via enteral feeding tubes (EFTs) is a common practice for children who cannot swallow properly. Although liquid formulations are the preferred dosage forms for this route of administration, little attention has been paid to the amount of drug that reaches the site of absorption after administration via an EFT. This systematic in vitro study aimed to identify formulation parameters and administration approaches that are critical for successful dose delivery via EFTs. For this purpose, drug recovery after administration of three different paediatric ibuprofen suspensions via different types of EFTs was studied using derivative UV spectrophotometry for quantification. Study results indicate that in addition to formulation parameters, feeding tube characteristics and the administration process can have a significant impact on the administered dose. The ratio between the total administered fluid volume (TAV), represented by the sum of dose- and flushing volume, and the feeding tube volume (FTV) proved to be a valuable indicator for assessing successful administration. Incorrect dosing and complications could be avoided if the TAV/FTV ratio was greater than 4. This and other knowledge gained in the study will help to make the administration of liquid paediatric medicines via EFTs both more effective and safer.

On Particular Regimens of Derivative UV-spectrophotometry for Comparative Analysis of Proteins

Bovine serum albumin and two oxygen transport proteins, hemocyanin from the snail Achatina fulica and bovine hemoglobin, were used to define what regimens of derivative UV-spectrophotometry are most appropriate for using it as an express technique for nondestructive comparative analysis of native proteins preparations. It was found that the fourth derivatives of proteins absorption spectra make it possible to detect the individual bands of aromatic amino acids in a way optimal for solving certain practical problems. An algorithm for calculating the fourth derivatives was selected experimentally. To verify the approach, the fourth derivatives of the native proteins spectra were reconstructed by combining those of individual aromatic amino acids spectra in the range of 240–300 nm. To demonstrate the individual differences between proteins, it is proposed to use the correlation coefficients of the fourth derivatives of spectra in the range of 240–300 nm or in the wavelength range of tyrosine and tryptophan. Although this approach does not provide for estimating the exact contents of individual aromatic amino acids in proteins, it allows comparing different proteins between each other. The proposed approach makes it possible to obtain an individual spectral “portrait” of a protein, which distinguishes it from other proteins and is useful as a reference for further experimental work with it.

Development and Validation of Analytical Methods for Simultaneous Estimation of Lercanidipine Hydrochloride and Enalapril Maleate

The fixed dose of lercanidipine hydrochloride(LH) and enalapril maleate (EM) is used to provide more effective control of hypertension. The research work was aimed at the development and validation of simple and sensitive analytical methods for their quantification from tablets. The simultaneous equation, first-order derivative, and multivariate spectrophotometric methods were developed for the simultaneous estimation of LH and EM in tablets. The simultaneous equation method involves a determination of LH and EM at 236 nm and 207 nm, respectively. First order derivative UV spectrophotometry method involves using a zero crossing point of LH at 330 nm and EM at 219 nm. Both methods were validated as per ICH Q2 (R2) guidelines and found to be accurate and precise as they exhibited <2% relative standard deviation. The limit of detection (LOD) and limit of quantitation (LOQ) for LH were found to be 0.26 μg/ml and 0.78 μg/ml respectively whereas LOD and LOQ for EM were found to be 0.41 μg/ml and 1.24 μg/ml respectively for simultaneous equation method. The LOD and LOQ for LH were found to be 0.39 μg/ml and 1.19 μg/ml respectively whereas LOD and LOQ for EM were found to be 0.31 μg/ml and 0.97μg/ml respectively for the first-order derivative method. Three Chemometric methods namely classical least square (CLS), principal component regression (PCR), and partial least square (PLS) were studied for the simultaneous determination of LH and EM in tablets using spectrophotometry. A set of 25 standard mixtures containing both drugs were prepared in the range of 5–25 μg/ml for both drugs. The analytical figure of merit (FOM) was determined for all three chemometric methods. The LOD values for LH were found to be 0.97, 0.93, and 0.94 μg/ml and 0.90,0.88, and 0.89 μg/ml for EM using CLS, PCR, and PLS modeling techniques. The proposed methods were user-friendly, rapid, and sensitive enough for the determination of LH and EM.

On particular Regimens of Derivative UV Spectrophotometry for Comparative Analysis of Proteins

On particular Regimens of Derivative UV Spectrophotometry for Comparative Analysis of Proteins

Method development and validation of solifenacin succinate in pharmaceutical dosage form using first order derivative UV spectrophotometry

Method development and validation of solifenacin succinate in pharmaceutical dosage form using first order derivative UV spectrophotometry

A poly(neutral red)/porous graphene modified electrode for a voltammetric hydroquinone sensor

In this work, a glassy carbon electrode was modified with poly(neutral red)/porous graphene (PNR/P-Gr/GCE). The electrode was developed for use in an electrochemical sensor to determine hydroquinone (HQ) in skin whitening creams. The electrode was prepared by drop casting P-Gr on the GCE surface, followed by electro-polymerization of neutral red in deep eutectic solvent (DES) without an acid dopant. The fabrication of the electrode was optimized and then characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The electrochemical properties of the electrode were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The PNR/P-Gr/GCE was used to determine HQ by adsorptive stripping differential pulse voltammetry (AdSDPV). Under optimal detection conditions, the electrode was 2 and 5 times more sensitive toward HQ than a P-Gr/GCE and an unmodified electrode, respectively. The developed electrode determined HQ concentrations from 0.005 to 70 µg mL−1 and exhibited a detection limit of 1.7 ng mL−1. The preparation of the electrode showed good repeatability (RSDs between 2.19 and 3.83%, n = 15), reproducibility (RSD < 1.87%, n = 6), and anti-interference properties. The proposed method successfully quantified HQ in skin whitening creams with recoveries between 89 ± 2 and 105.1 ± 0.2%. There was no significant difference at a 95% confidence level between the results obtained using the proposed method and those from UV-derivative spectrophotometry. This electrode presents a promising approach to HQ determination in skin whitening creams.

Simultaneous determination of dorzolamide and timolol by first-order derivative UV spectroscopy in simulated biological fluid for in vitro drug release testing

Dorzolamide hydrochloride and timolol maleate is a well-established fixed-dose combination for the treatment of glaucoma worldwide. The utilization of simulated biological fluids can give a superior understanding of the release mechanisms and practicable in vivo nature of a dosage form that can improve the predictive potential of in vitro drug release testing. No method has been reported so far for the simultaneous estimation of dorzolamide and timolol in simulated tear fluid. In the present study, a simple, precise, and accurate first-order derivative ultraviolet spectrophotometric method for the routine analysis of dorzolamide and timolol in simulated tear fluid is proposed for in vitro drug release testing. The developed method was validated as per International Conference on Harmonization guidelines Q2 (R1). First-order derivative UV spectrophotometry was successfully applied to separate the overlapping peaks of dorzolamide and timolol by measuring peak amplitude at 251.80 nm and absorbance at 295.00 nm, respectively. The method was found to be accurate and precise, with a recovery range of 98.0 –101.0% and low relative standard deviations (<2.0%). The developed method was successfully applied for in vitro drug release testing of in-house in situ gel and marketed eye drops containing dorzolamide and timolol. Various mathematical models were adopted to fit the in vitro drug release profile. It was observed that the drug release of both drugs from the in situ gel and the marketed solution were best fitted by the Higuchi and first-order kinetic models, respectively. Moreover, the analysis of variance (ANOVA) provision was used for the validation of results. Overall, with the advantages of simple and fast operations, as well as reliability, the proposed method offers an ideal platform for routine analysis as compared to other high-cost and time-consuming chromatographic techniques. Having access to such a robust method will encourage the use of simulated tear fluid for in vitro drug release testing of ocular products and help to predict the in vivo performances of ophthalmic preparations.

Poly(phenol red) hierarchical micro-structure interface enhanced electrode kinetics for adsorption and determination of hydroquinone

A simple, new strategy for enhancing the electrochemical adsorption and determination of hydroquinone was proposed that involved modifying a glassy carbon electrode with a hierarchical structure of poly(phenol red) microparticles (P(PhR)MPs electrode). The electrochemical oxidation of hydroquinone at the P(PhR)MPs electrode displayed quasi-reversible behavior. The electrocatalysis and adsorption kinetics of the P(PhR)MPs toward hydroquinone were proved using chronoamperometry and EIS. Hydroquinone was determined by the P(PhR)MPs electrode at concentrations from 10 ng mL−1 to 100 μg mL−1 (91 nmol L−1 to 908 μmol L−1) using adsorptive anodic stripping voltammetry (AdASV) with an accumulation time of 30 s. Electrode sensitivity was 3.54 μA μg−1 mL cm−2, and limits of detection (LOD) and quantitation (LOQ) were 2.7 ng mL−1 (25 nmol L−1) and 10 ng mL−1 (91 nmol L−1), respectively. The P(PhR)MPs electrode preparation exhibited good repeatability (RSDs between 1.66 and 3.87% (n = 15)), good reproducibility (RSD < 3.2% n = 6) and excellent anti-interference properties. The proposed method successfully quantified hydroquinone in skin whitening products with recoveries between 93 ± 2 and 102 ± 1% and there was no significant difference at a 95% confidence level between the results from the proposed sensor and those from UV-derivative spectrophotometry. The developed poly(phenol red) hierarchical micro-structure showed that it could be used as an interface for application in electrochemical sensors or biosensors.

Feasible oxidative degradates separation with instant quantification of two non-classical β-lactams by derivative UV spectrophotometry and TLC densitometry

The present paper focuses on the study of stability of two non-classical β-lactam drugs, namely meropenem (MP) and ertapenem (EP) that are highly susceptible to degradation. We proposed two facile and accurate derivative UV spectrophotometric and TLC densitometric methods for fast separation of MP and EP from their oxidative degradates. Firstly, first derivative (D1) and derivative ratio (DR1) techniques were successfully implemented at 325, 324 nm and 322, 320 nm, respectively. Secondly, TLC densitometry was apparently applied at 254 nm, utilizing 2-propanol–methanol–water as a developing system. Oxidative degradation is elucidated by infrared and mass spectrometry. Both developed methodologies aided to determine MP and EP in pure forms, prepared mixtures with oxidative degradates and pharmaceutical vials. Validation was performed in accordance with USP guidelines. Despite both derivative techniques attained the same sensitivity, DR1 method advantageously improved the selectivity by tenfold than D1. All methods considered stability, indicating to oxidative degradation. Statistical comparison and single-way ANOVA emphasized insignificant differences among suggested methods with other referenced ones. Multiple privileges were encountered in UV spectrophotometric and TLC densitometric methods because no sophisticated handling, minimal solvent consumption, no prior separation stages, easiness and wide implementation in QC laboratories of limited budget levels.

Comparison of UV-spectrophotometry and high- performance liquid chromatography for determination of chlorpheniramine maleate in tablet in the presence of tartrazine

The presence of tartrazine, yellow coloring agent, suspected to interfere with the CPM determination in CPM tablets using direct spectrophotometry or high performance liquid chromatography. Overlap spectra of tartrazine and CPM at an analytical wavelength and peak tailing were the main problem occurs in CPM tablets analysis. The aim of this study was to develop a derivative UV spectrophotometry and a modified HPLC to overcome the problem in CPM tablet analysis. Both validated methods were applied for the determination of CPM content in three registered CPM tablets. As a result, the first derivative spectrophotometry method obtained the δA/δλ of tartrazine in matrix tablet was nearly zero at the wavelength of 232 nm and did not interfere with the δA/δλ of CPM. The selective mobile phase for separation of CPM from tartrazine using HPLC method was a mixture of phosphate buffer pH 4 and methanol (60:40 v/v) with a flow rate of 1 ml/min. The CPM separated from tartrazine and other peaks in sample(s) with Rs of >1.5 The linearity, accuracy, and precision of these two methods fulfilled the reference requirement. No significant difference observed between the CPM content in artificial tablets when analyzed using first-derivative spectrophotometry and HPLC method. The concentration of CPM in one registered tablet that had been assayed using spectrophotometry, HPLC and the standard method was not significantly different. As a conclusion first-derivative spectrophotometry and HPLC method were valid for the determination of CPM in a tablet containing tartrazine. However, the first-derivative spectrophotometry method was more efficient than HPLC.

Development of a First-Order Derivative UV Spectrophotometric Method for the Assay and Solubility Evaluation of Lamotrigine and Nicotinamide Cocrystals

Pharmaceutical cocrystals are composed of a drug and a coformer and are currently gaining attention due to their possibility of improving drug solubility. Quantitative determination of cocrystals is usually carried out by liquid chromatography method, but an alternative for the same is derivative UV spectrophotometry. Cocrystals of lamotrigine (LAM) were formed with nicotinamide (NIC) in order to improve the solubility of LAM. The aim of this study was to develop and validate a simple, low-cost, environment friendly, first-order derivative spectrophotometric method for simultaneous determination of LAM and NIC in cocrystals. Determination of LAM and NIC was performed at 244.4 and 271.6 nm, respectively. The method was accurate with recovery values of 98.21-101.52%, and precise (relative standard deviation (RSD) < 1.88%). Robustness evaluated by Plackett-Burman design showed no significant influence of the factors (pH, scanning speed, and sonication time) on LAM and NIC assays. The developed method was compared with a high performance liquid chromatography (HPLC) method and applied to study the cocrystal stoichiometry and solubility. The results indicated a molar ratio of 1:1 and that the cocrystal is more soluble than the drug. This study demonstrated that the first-order derivative method is feasible for drug and coformer determination in cocrystals and is a suitable alternative to chromatographic methods.

Derivative UV Spectrophotometric Detection of Some Common Pesticides in Simulated Samples of Beverages

Pesticides are widely used in India because of their applications in agriculture and household purposes. Due to their high toxicity, over use and easy availability they are encountered in suicidal, accidental and homicidal cases. Poisoning with pesticides are common in developing countries as compared to western countries. Because of large number of cases of deaths due to pesticide poisoning it is imperative to develop sensitive, reliable and accurate methods for their detection from the viscera samples, biological materials and common substrates such as beverages etc. recovered from the crime scene. Derivative UV-Vis spectrophotometry is one of the most widely used techniques for detection of pesticides in viscera and other matrices such as beverages etc. In the present study, pesticides were spiked in beverages like Coffee, Tea, Fruity, Mountain dew and Alcohol and then analysed using derivative UV spectrophotometry. Further, the effect of matrices was studied on the UV spectra of pesticides.

Comparison of high-performance thin layer chromatography/UV-densitometry and UV-derivative spectrophotometry for the determination of trimetazidine in pharmaceutical formulations.

New methods for assaying trimetazidine dihydrochloride on the basis of thin layer chromatography and spectrophotometry are proposed and compared in the paper. In HPTLC/UV-densitometry, separation is achieved by using a mobile phase composed of ammonia-methanol (30:70, V/V) on silica gel HPTLC plates F254. Quantification using a non-linear calibration curve is accomplished by densito-metric detection at 230 nm. Derivative spectrophotometric determination of trimetazidine dihydrochloride is carried out from the fourth derivative of the absorbance at 233 nm in peak-zero mode. Statistical comparison led to the conclusion that there is no significant difference between the two studied methods and, moreover, that they demonstrate satisfactory accuracy and precision for routine applications.

Quantitative Analysis of Ciprofloxacin in an Ophthalmic Solution Using UV Absorption Spectrophotometry and Derivative Spectrophotometry

The quantitative analysis of ciprofloxacin in an ophthalmic solution was performed by UV absorption spectrophotometry and first derivative spectrophotometry. The UV absorption spectra of standard series and samples containing ciprofloxacin were recorded. Then, the derivative of UV absorption spectra was obtained for the derivative spectrophotometric analysis of the related drug. Linear regression equations in the linear concentration range of 3.0-28.0 µg/mL for analysis of ciprofloxacin were obtained by using direct absorbance measurement at 278.9 nm and using the dA/dλ values at 283.2 nm. The recovery assay results were found between 97.8 to 102.0 %. It was observed that the limits of detection and quantification were 0.74 and 2.74 μg/mL for UV absorption spectrophotometry and 0.60 and 2.00 μg/mL for first derivative spectrophotometry, respectively. Analysis results indicated that the proposed methods were precise, accurate and reliable for the determination of ciprofloxacin in commercial samples.

Microplate assay for lipophilicity determination using intrinsic fluorescence of drugs: Application to a promising anticancer lead, pyridoclax

Lipophilicity must be necessarily determined in drug discovery since this physicochemical property will directly influence the pharmacokinetics of a drug as its pharmacodynamics profile. Pyridoclax is an original lead, recently identified as very promising in treatment of chemoresistant cancers. The partition coefficient (Kp) of this anticancer drug was determined by microplate assays, well adapted in drug discovery, since being rapid, and requiring only poor drug amounts. The analytical approach was performed either by UV derivative spectrophotometry after validation thanks to a set of basic, neutral and acid reference substances, or originally, by raw fluorescence spectrophotometry by taking advantage of the pyridoclax intrinsic fluorescence. Large unilamellar vesicles (LUVs) were formulated from soybean-, egg-, or dipalmitoyl-phosphatidylcholine, characterized in terms of granulometric properties, ζ potential (determined by DLS), and of phospholipid content (quantified by 1H NMR, also in presence of cholesterol). Whatever the detection method used, log Kp of pyridoclax were in the same magnitude order, and pyridoclax appeared as a lipophilic compound. It was also established that interactions between this lead and biomimetic membranes were influenced by the relative fluidity of the membranes, as confirmed by results of a liposome leakage assay.

Development, validation and application of first derivative spectroscopy ratio method for estimation of Bradford assay

Several, novel and different spectrophotometric methods based on UV and first-order derivative spectrophotometry, were developed to increase accuracy and improve sensitivity of the Bradford assay for protein quantification in hair samples. The linear calibration function was established in concentration range 2–90 μg/mL at pH 0.6.Significant improvement over the classical method was observed using three different methods based on first-order derivative spectra: signals at 550 nm (1D550), numerically integrated area under curve from 545 to 565 nm (AUC1D545-565) and the ratio of peaks at 550 and 420 nm (1D550/1D420). The correlation coefficients were 0.9924, 0.9932 and 0.9991, respectively. Accordingly, the best correlation was observed by the 1D550/1D420 ratio method. The LOD of 15.67 μg/mL (1D550), 14.80 μg/mL (AUC1D545-565), 5.45 μg/mL (1D550/1D420) and LOQ of 47.48 μg/mL (1D550), 44.85 μg/mL (AUC1D545-565), 16.51 μg/mL (1D550/1D420), were calculated.The sample recoveries for 1D550/1D420 ratio method have proven that its accuracy (95.05%) is within the acceptable interval of recoveries. The obtained 1.55% RSD for precision fell well within the criteria accepted in bioanalytical method validation. This method was applied for determination of total proteins in hair samples. Also, the influence of different chemical treatments on total protein amount in hair sample was investigated.

A REVIEW ON DERIVATIVE UV-SPECTROPHOTOMETRY ANALYSIS OF DRUGS IN PHARMACEUTICAL FORMULATIONS AND BIOLOGICAL SAMPLES REVIEW

The review article deals with theoretical aspects of Derivative UV-Spectrophotometry. The method gains significance using the first and second derivative of the transmission spectra with respect to wavelength. Generated optical derivatives are compared to the known numerical derivatives. The derivative spectra from 1st to 4th are consequently discussed. This provides valuable insight into the uses and limitations of this technique for chemical analysis. Measurement techniques and methods of obtaining derivative spectra are discussed. The degree of polynomial fit on the smoothness of derivative spectra and signal-to-noise ratio is described. Application of UV derivative spectrometry for determination of single and multicomponent analysis is shown. Derivative spectrophotometry possibly improves the selectivity and sensitivity of determination which has been illustrated.

Direct DOC and nitrate determination in water using dual pathlength and second derivative UV spectrophotometry

UV spectrophotometry is largely used for water and wastewater quality monitoring. The measurement/estimation of specific and aggregate parameters such as nitrate and dissolved organic carbon (DOC) is possible with UV spectra exploitation, from 2 to multi wavelengths calibration. However, if nitrate determination from UV absorbance is known, major optical interferences linked to the presence of suspended solids, colloids or dissolved organic matter limit the relevance of UV measurement for DOC assessment. A new method based on UV spectrophotometric measurement of raw samples (without filtration) coupling a dual pathlength for spectra acquisition and the second derivative exploitation of the signal is proposed in this work. The determination of nitrate concentration is carried out from the second derivative of the absorbance at 226 nm corresponding at the inflexion point of nitrate signal decrease. A short optical pathlength can be used considering the strong absorption of nitrate ion around 210 nm. For DOC concentration determination the second derivative absorbance at 295 nm is proposed after nitrate correction. Organic matter absorbing slightly in the 270–330 nm window, a long optical pathlength must be selected in order to increase the sensitivity. The method was tested on several hundred of samples from small rivers of two agricultural watersheds located in Brittany, France, taken during dry and wet periods. The comparison between the proposed method and the standardised procedures for nitrate and DOC measurement gave a good adjustment for both parameters for ranges of 2–100 mg/L NO3 and 1–30 mg/L DOC.

Estimation of Delafloxacin Using Derivative Spectrophotometry and Area Under Curve in Bulk Material and in Laboratory Mixture

Simple, specific, rapid and accurate UV-spectrophotometric methods have been developed using a solvent acetonitrile (50 %) to determine delafloxacin in bulk material and in laboratory mixture. “Method A” is zero order derivative UV- spectrophotometry using absorbance, “Method B” is zero order derivative UV-spectrophotometry using Area Under Curve (AUC) technique, “Method C” is first order derivative UV-spectrophotometry using amplitude, “Method D” is First Order Derivative UV-spectrophotometry- AUC,“Method E” is Second Order Derivative UV-spectrophotometry using amplitude and “Method F” is second order derivative UV- spectrophotometry using (AUC) technique. The developed methods have shown excellent results in terms of linearity and range, accuracy, precision and Limit of Detection (LOD) and Limit of Quantification (LOQ). In all Methods, delafloxacin obeyed linearity in the concentration range of 2 – 12 μg/mL with (r2 &gt; 0.999). All these methods were applied for estimation of delafloxacin in laboratory mixture. All the above mentioned methods were validated considering linearity and range, accuracy, precision, ruggedness and sensitivity.