HPLC and Chemometrically‐Assisted Spectrophotometric Estimation of Two Binary Mixtures for Combined Hypertension Therapy

Recent development in derivative ultraviolet/visible absorption spectrophotometry: 2004–2008

“…Derivative transform was applied to the original absorption signal together with its FWT generalization. Commercial tablets; no significant difference in the performance of the three methods regarding the accuracy and precision, respectively [166] Fenbufen; Ketoprofen By classical spectrophotometryzero-order derivative, 1st-and 2nd-order DS using "peak-peak" and, "peak-zero" measurements; in pharmaceuticals By ratio spectra first-order DS (graphical method) and chemometric method (numerical method, CLS); in the graphical approach, absorption spectra of QA and its binary mixtures in the selected spectral range of 210-280 nm were divided by standard spectrum of 10 g mL −1 HCT and their absorption spectra obtained, in the similar way, ratio spectra of HCT in region of 210-350 nm were obtained by using standard spectrum of 12 g mL −1 QA; 1st derivative of ratio spectra obtained in above steps calculated by = 5 nm interval for both drugs Lamivudine; Zidovudine Derivative-differential UV and compensation technique at 246 and 263 nm; also, HPLC; in human serum and pharmaceutical formulations -No differences were found between the methods [189] Levamizole; Oxyclozanide Numerical (PLS and PCR calibrations) and graphical (2nd-derivative spectrophotometry, amplitudes at 263.6 and 294 nm, respectively) methods; in bolus 5-25 for both drugs All proposed methods validated by using independent synthetic mixtures and standard addition technique [190] Loratadine; Pseudoephedrine By three different methods: (1) employs multi-wavelength spectroscopy using seven mixed standards and 257.0 and 283.0 nm as two wavelengths for estimation; (2) 1st derivative using 263.0 and 308.6 nm as zero-crossing points; (3) HPLC 0-40; 0-800 Results validated statistically and by recovery studies [191] Metformin; Pioglitazone 2nd derivative at 257.25 and 227.55 nm, respectively in spectra of their solutions in a mixture of methanol and acetonitrile (30:70) and HPLC; in combined dosage forms 4-20 for both drugs Both methods were validated and the results were compared statistically; they were found to be accurate, precise and specific [192] Routine analysis of both drugs in quality control laboratories [194] N-Butylscopolamine; Oxazepam 1st derivative by zero-crossing method at 226 and 257 nm, respectively; acetonitrile was selected as solvent in which both compounds showed well-defined bands; both analytes showed good stability in this solvent when their solutions were exposed to light and temperatures between 20 and [196] Paracetamol; Aceclofenac or Tramadol Zero-crossing point technique and the compensation technique; in combination solid dosage forms 0-24 for all drugs - [197] Paracetamol; Valdecoxib DS to eliminate spectral interference by measuring absorbances at two wavelengths 301 and 284 nm, respectively, in two-component tablet formulation -Results validated statistically and by recovery studies [198] Piracetam (PIR); Vincamine (VIN) By three different methods: (1) using ratio spectra 1st derivative at 209 and 293 nm; [202] Aspirin, Salicylic acid, Paracetamol 1st and 2nd derivatives of the ratio spectra and measurement at zero-crossing wavelengths. The ratio spectra were obtained by dividing the absorption spectrum of the mixture by that of one of the components; in synthetic mixtures and dosage forms 0.07-0....…”

Development and validation of TLC–densitometric method for simultaneous determination of two binary antihypertensive mixtures containing felodipine in fixed dose combinations

“…In recent years, FLD and RMP have been successfully used in combination in the treatment of hypertension, and pharmaceutical preparations containing both drugs have been marketed, permitting once‐a‐day administration. Although many methods have been reported in the literature for the determination of FLD and RMP individually or in other combinations, there are few spectrophotometric, spectrofluorimetric and RP‐HPLC methods for the determination of an FLD–RMP combined dosage (El Yazbi et al ., ; Rontogianni et al ., ).…”

“…Only a few methods have been reported in the literature for the assay of FLD–MTP mixture, using chemometrically assisted spectrophotometric, HPLC (Rontogianni et al ., ; Salem and Abdallah, ; Wen‐Gang et al ., ) and spectrofluorimetric methods (Walash et al ., ; Zhang et al ., ).…”

Simultaneous spectrophotometric determination of titanium oxide and iron oxide nanoparticles in water by using PLS algorithm

“…Method PLS has shown its efficiency for the UV-spectra separation for analysis of different ions mixtures, such as Fe(III), Co(II), Cu(II) [25], Sb (III) and Sb (V) [26], phosphate and silicate in water and soil samples [27], mixtures of drugs [28,29], mixtures of organic matter and nitrates in wastewater [30] and many others. The application of this method for the dispersed particles detection is not known, so far.…”