Continuous wavelet transform and integration of discrete wavelet transform with principal component analysis and fuzzy inference system for the simultaneous determination of ethinyl estradiol and drospirenone in combined oral contraceptives

In this study, the spectrophotometric method integrated with continuous wavelet transform (CWT) and coupled discrete wavelet transform (DWT) with fuzzy inference system (FIS) was developed for the simultaneous determination of ethinyl estradiol (EE) and drospirenone (DP) in combined oral contraceptives (COCs). The CWT approach was performed in the linearity range of 0.6-6 µg/mL for EE and 0.9 to 18 µg/mL for DP. Biorthogonal with an order of 1.3 (bior1.3) at a wavelength of 216 nm and Daubechies with an order of 2 (db2) at a wavelength of 278 nm were selected as the best wavelet families for obtaining the best zero crossing point for EE and DP, respectively. The limit of detection (LOD) of 0.7677 and 0.3222 µg/mL and the limit of quantification (LOQ) of 2.326 and 0.9765 µg/mL were obtained for EE and DP, respectively. The mean recovery of 103.24% and 99.77%, as well as root mean square error (RMSE) of 0.1896 and 0.1969, were found for EE and DP, respectively. In the DWT, the absorption of the mixtures was decomposed using different wavelets named db4, db2, Symlet2 (sym2), and bior1.3. Each of the wavelet outputs was dimension reduced by the principal component analysis (PCA) method and considered as FIS input. The wavelet of db4 with the coefficient of determination (R2) of 0.9979, RMSE of 0.0968, and mean recovery of 100.63% was chosen as the best one for the EE, while bior1.3 with R2 of 0.9955, RMSE of 0.4055, and mean recovery of 101.93% was selected for DP. These methods were successfully used to analyze the EE and DP simultaneously in tablet pharmaceutical formulation without any separation step. The suggested methods were compared with a reference method (HPLC) using analysis of variance (ANOVA) at a 95% confidence level, and no significant difference was observed in terms of accuracy. The suggested chemometric methods are reliable, rapid, and inexpensive, and can be used as an environmentally friendly alternative to HPLC for the simultaneous estimation of the mentioned drugs in commercial pharmaceutical products.

Simultaneous Determination of Estradiol Cypionate and Medroxyprogesterone Acetate Hormones in Injectable Suspension by UV Spectrophotometry Based on Least-Squares Support Vector Machine and Fuzzy Inference System: Comparison with HPLC

BACKGROUND

The combination of estradiol cypionate (ECA) and medroxyprogesterone acetate (MPA) is used to prevent pregnancy in women. The analysis of the ECA and MPA combination reveals a challenge due to the strong overlap of the spectra of these compounds.

OBJECTIVE

Spectrophotometry techniques along with chemometrics methods are simple, fast, precise, and low-cost for the simultaneous determination of ECA and MPA in a combined pharmaceutical dosage form.

METHODS

Two developed approaches, the least-squares support vector machine (LSSVM) and fuzzy inference system (FIS), along with a spectrophotometric method were proposed to solve such a challenging overlap.

RESULTS

Based on the cross-validation method, the regularization parameter (γ) and width of the function (σ) in the LSSVM model were optimized and the root mean square error (RMSE) values were found to be 0.3957 and 0.2839 for ECA and MDA, respectively. The mean recovery values were 99.87 and 99.63% for ECA and MDA, respectively. The FIS coupled with principal component analysis (PCA) showed mean recovery percentages equal to 99.05 and 99.50% for ECA and MDA, respectively. Also, the RMSE of both components was lower than 0.3.

CONCLUSION

The analysis results of a real sample (injection suspension) using the proposed methods were compared with HPLC by a one-way analysis of variance (ANOVA) test, and no significant differences were found in the results.

HIGHLIGHTS

Intelligent methods were proposed for the simultaneous determination of ECA and MPA. The least-squares support vector machine and fuzzy inference system along with spectrophotometry were used. HPLC as a reference method was performed and compared with chemometrics methods. The benefits of the proposed approaches are that they are rapid, simple, low-cost, and accurate.

Comparative Study of Continuous Wavelet Transform and Multivariate Calibration for the Simultaneous Spectrophotometric Determination of Tamsulosin and Solifenacin in Pharmaceutical Formulation and Biological Sample

BACKGROUND

Spectrophotometry alone is not applicable for the simultaneous determination of drugs in a multicomponent pharmaceutical formulation owing to their overlap.

OBJECTIVE

In this study, the combination of UV-Vis spectrophotometry and chemometric methods, including continuous wavelet transform (CWT) and partial least-squares (PLS) was presented for the simultaneous estimation of tamsulosin (TAM) and solifenacin (SOL) in synthetic mixtures, commercial formulations, and a biological sample.

METHODS

The simultaneous spectrophotometric determination of TAM and SOL in binary mixtures, a real sample, and a biological sample was performed by applying CWT and PLS approaches.

RESULTS

In the CWT method, two various wavelet families named Daubechies (db2) at wavelength 223 nm and Biorthogonal (bior1.3) at wavelength 227 nm based on the appropriate zero-crossing point were selected for TAM and SOL, respectively. The linear ranges of TAM and SOL were 0.25-4 μg/mL and 10-30 μg/mL, respectively. The LODs were 0.0459 μg/mL and 0.2085 μg/mL, while the LOQs were 0.3208 μg/mL and 0.6495 μg/mL for TAM and SOL, respectively. The average recovery values of 18 mixtures were 98.28% and 97.79% for TAM and SOL, respectively. Also, the root mean square error (RMSE) of both components was lower than 2.3. Based on the k-fold cross-validation in the PLS approach, the optimum number of components related to TAM and SOL were 9 and 5 with a mean square error prediction (MSEP) of 0.0153 and 0.0370, respectively. The mean recovery values of the test set were found to be 100.09% for TAM and 99.95% for SOL where RMSE values were 0.0064 and 0.0169 for TAM and SOL, respectively.

CONCLUSION

Analysis of variance (ANOVA) was applied to the results of the real sample and there was no significant difference between the proposed methods and HPLC as a reference technique. The result obtained revealed that the proposed methods were found to be fast, facile, economical, and precise, and provide a suitable alternative to the HPLC technique for the concurrent determination of TAM and SOL in QC laboratories.

HIGHLIGHTS

UV-Vis spectrophotometry combined with CWT and PLS was developed. Simultaneous analysis of TAM and SOL was performed using the proposed approaches. These methods were implemented on synthetic mixtures, commercial formulations, and a biological sample. ANOVA test was used to compare the suggested methods and the HPLC technique.

Benzodiazepines in complex biological matrices: Recent updates on pretreatment and detection methods

Benzodiazepines (BDZs) are used in clinics for anxiolysis, anticonvulsants, sedative hypnosis, and muscle relaxation. They have high consumptions worldwide because of their easy availability and potential addiction. They are often used for suicide or criminal practices such as abduction and drug-facilitated sexual assault. The pharmacological effects of using small doses of BDZs and their detections from complex biological matrices are challenging. Efficient pretreatment methods followed by accurate and sensitive detections are necessary. Herein, pretreatment methods for the extraction, enrichment, and preconcentration of BDZs as well as the strategies for their screening, identification, and quantitation developed in the past five years have been reviewed. Moreover, recent advances in various methods are summarized. Characteristics and advantages of each method are encompassed. Future directions of the pretreatment and detection methods for BDZs are also reviewed.

Application of net analyte signal and principal component regression for rapid simultaneous determination of Levodopa and carbidopa in commercial pharmaceutical formulation and breast (human) milk sample using spectrophotometric method

In this study, a UV-vis spectrophotometric method coupled with net analyte signal (NAS) and principal component regression (PCR) as multivariate calibration methods were used for the simultaneous determination of levodopa (LEV) and carbidopa (CBD) in prepared mixtures, pharmaceutical formulation, and breast milk sample. The mean recovery of the NAS model was 98.10% and 99.60% for LEV and CBD, respectively. Also, the relative standard deviation (RSD%) values were found to be lower than 5.5% and 4% for LEV and CBD, respectively. On the other hand, the mean recovery of LEV and CBD related to the PCR method was obtained at 96.86% and 92.43%, respectively. K-Fold cross-validation was used to estimate the number of components, which was 7 and 3 with a mean square error prediction (MSEP) of 1.50 and 7.14 for LEV and CBD, respectively. The results revealed that the NAS model was better than the PCR model. Additionally, the proposed NAS-based calibration method was successfully developed for the simultaneous analyses of LEV and CBD in a commercial tablet and breast milk.

A Simple and Reliable Liquid Chromatographic Method for Simultaneous Determination of Five Benzodiazepine Drugs in Human Plasma

Benzodiazepines (BZDs) are one of the most important drugs that have been used in the treatment of neuropsychological disorders. Indeed, BZDs are abused by drug addicts regardless of their therapeutic uses. Therefore, it was important in forensic and clinical toxicology to reach an easy and reliable method for the screening and quantification of BZDs in the human plasma matrix. In the current work, five BZDs, namely bromazepam, clonazepam, lorazepam, nordiazepam and diazepam were simultaneously separated and detected by a simple and reliable RPLC method in a human plasma matrix. Isocratic mobile elution consisting of 20 mmol L−1 phosphate buffer (pH 7.0) and methanol (50:50, v/v) on a Symmetry C18 column was employed. The flow rate, wavelength and column temperature were fixed at 1.0 mL min−1, 214 nm and 40 °C, respectively. The proposed method was validated, giving a linearity within the concentration ranges 5–500 ng mL−1 for bromazepam and diazepam, 3–500 ng mL−1 for clonazepam and lorazepam and 1–500 ng mL−1 for nordiazepam with a determination coefficient (R2) more than 0.9992. The LOD values for the selected BZDs ranged from 0.54 to 2.32 and from 1.78 to 7.65 ng mL−1 for standard methanolic and plasma matrices, respectively. Precision, accuracy, selectivity, stability, and robustness were some of the terms considered in validating the current RPLC method. Based on these results, a simple and reliable RPLC method was successfully applied to quantify BZDs in human plasma matrix appearing with recoveries ranging from 96.5 to 107.5% and interday RSD less than 4%. The current developed method was useful for rapidly screening the most commonly used BZDs in the market within their therapeutic concentration ranges.

Application of Tandem Dispersive Liquid-Liquid Microextraction as an Efficient Method for Preconcentration of Two Antidepressant Drugs in Real Samples Combined with High Performance Liquid Chromatography

In the present work, tandem dispersive liquid-liquid microextraction (TDLLME) coupled with liquid chromatography was used for the determination of the two antidepressant drugs citalopram (CIT) and sertraline (SER) in complicated matrices. Indeed, the present approach was used to improve the suitability and appropriateness of the dispersive liquid-liquid microextraction (DLLME) method in complicated matrices. Firstly, 10 mL of the sample solution containing the two understudied drugs was extracted into an organic solvent (200 μL of 1,2-dichloromethane) using the DLLME method. Then the extracted analytes were back-extracted into 100 μL of an aqueous acceptor phase. The total extraction time of this method is about 6 min. To achieve the best efficiency for this method, efficient parameters like the kind and volume of the organic solvent and the effect of the ionic strength on the effectiveness of extraction were reviewed and improved. Under the optimized experimental conditions, TDLLME showed good linearity in the range of 100.0-7000.0 ng mL-1. The limits of detection were found to be 10.0 ng mL-1 for CIT and 2.0 ng mL-1 for SER. The relative standard deviation (RSD) is obtained in the range of 0.7-4.1%.

Interest of flow injection spectrophotometry as an orthogonal method for analyzing biomolecule aggregates: Application to stressed monoclonal antibody study

This study aimed to explore the suitability of flow injection spectrophotometry (FIS) to analyze three degraded therapeutic monoclonal antibodies (bevacizumab, nivolumab, and rituximab). For this purpose, aggregates were generated with stirring, freeze-thaw, and heat stresses. The intact and stressed mab samples were filtered with 0.22 µm hydrophilic filters and analyzed by size exclusion chromatography (SEC), cation-exchange chromatography (CEX), and FIS. In terms of quantitative and qualitative analysis, protein loss and structural changes were assessed. Various aggregates profiles were obtained according to the mabs and the stresses. FIS allowed performing very satisfactory quantifications for each mab with intermediate precision RSD < 3.0 % and recovery between 97.9 and 102.0 %. From the protein loss measurements, it appears that SEC underestimates the mab aggregate proportions up to two times less as compared with FIS since the latter avoids any non-specific interactions (electrostatic or hydrophobic interactions). Using second derivative spectroscopy and multivariate data analysis, we noticed apparent structural differences, located in the regions 245-265 nm for rituximab and nivolumab and 280-300 nm for bevacizumab, depending on the stress. The FIS complementarity with the other techniques used in this study allowed us to demonstrate that the three mabs behave differently for a given stress condition. While extreme mechanical stress formed large aggregates irrespective of the mabs, rituximab showed to be less stable and more sensitive than the two other mabs under freeze-thaw and heat stresses, generating large aggregates (>200 nm) and partial unfolding. Nivolumab tends to form small aggregates less than 50 nm when heated and freeze-thawed. Moreover, freeze-thaw seems to generate native IgG-1 aggregates with rituximab. Similarly, bevacizumab showed to form these IgG-1 aggregates and was resistant to freeze-thaw, likely thanks to trehalose cryoprotectant from its formulation. Finally, FIS associated with multivariate analysis can provide rich information in one single run and appears to be a fast, simple, and reliable method to set complementary and orthogonal approaches for protein aggregates monitoring.

Improved spectral resolution for the rapid simultaneous spectrophotometric determination of sofosbuvir and daclatasvir as anti hepatitis C virus drugs in pharmaceutical formulation and biological fluid using continuous wavelet and derivative transform

In this study, the simultaneous spectrophotometric estimation of Sofosbuvir (SOF) and Daclatasvir (DAC) in synthetic mixtures and tablet formulation in the presence of overlapping spectra was performed based on continuous wavelet transform (CWT) and derivative spectrophotometry (DS) methods without any separation process. The Coiflet (Coif2) and Daubechies (Db3) wavelet families with wavelength of 256 nm and 218 nm were obtained as the best families for the simultaneous determination of SOF and DAC, respectively. Also, the first derivative absorption spectra revealed the best results corresponding to the analysis of SOF and DAC at 237 nm and 291 nm, respectively. The ranges of limit of detection (LOD) and limit of quantitation (LOQ) related to the CWT and DS methods were 2.45 × 10^-3 to 0.5054 and 6.91 × 10^-3 to 0.6027, respectively. Mean recovery values of SOF and DAC in synthetic mixtures for CWT approach were 98.55%, 98.09% and in DS method were 98.78% and 95.83%, respectively. Real samples, including Sovodak tablet and urine was used for accurate simultaneous determination of the mentioned components. Analyzing Sovodak tablet was implemented using high-performance liquid chromatography (HPLC) as a reference method that the results were near to the CWT and DS methods. In order to investigate the existence of significant differences between the methods, analysis of variance (ANOVA) test at the 95% confidence level was performed but no significant differences were observed. In addition, the amounts of SOF and DAC in the complex matrix of biological sample were well predicted by the proposed methods.

The application of continuous wavelet transform based on spectrophotometric method and high-performance liquid chromatography for simultaneous determination of anti-glaucoma drugs in eye drop

In this study, a fast, low-cost, accurate, and precise spectrophotometric method based on the continuous wavelet transform (CWT) was assayed to determine dorzolamide (DOR) and timolol (TIM) in an eye drop sample simultaneously. Different wavelet families were investigated to select the best family for analyzing the DOR and TIM. The Mexican hat wavelet (MHW) family with the wavelength of 281 nm and Gaussian wavelet family (gaus2) in the wavelength of 267 nm were found for the simultaneous analysis of DOR and TIM, respectively. Mean recovery values of synthetic mixtures were found 97.44%±2.63 and 99.18%±4.00 for DOR and TIM, respectively. The root mean square errors (RMSE) of DOR and TIM were achieved 0.5550 and 0.3306, respectively. Eye drop as a real sample was analyzed by spectrophotometry coupled with the CWT technique, as well as high-performance liquid chromatography (HPLC) as a reference method. The obtained results were compared with each other by the one-way analysis of variance (ANOVA) test and there was no significant difference between them.

Rapid analysis of fungicides in tea infusions using ionic liquid immobilized fabric phase sorptive extraction with the assistance of surfactant fungicides analysis using IL-FPSE assisted with surfactant

A green, simple, inexpensive, and sensitive ionic liquid immobilized fabric phase sorptive extraction method coupled with high performance liquid chromatography was developed for rapid screening and simultaneous determination of four fungicides (azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin) residues in tea infusions. This IL modified extraction fiber is capable of extracting target analytes directly from complicated tea water matrices with the addition of surfactant. A series of extraction conditions were investigated by one-factor-at-a-time approach and orthogonal test. After a series experiments, the optimum conditions were found to be 10% [HIMIM]NTf₂ as coating solution, 2min vortex time, 500μL acetonitrile as dispersive solvent and 2min desorption time. Under the above conditions, the proposed technique was applied to detect fungicides from real tea water samples with satisfactory results.