Discrete Wavelet Transform-Partial Least Squares Versus Derivative Ratio Spectrophotometry for Simultaneous Determination of Chlorpheniramine Maleate and Dexamethasone in the Presence of Parabens in Pharmaceutical Dosage Form

Purpose: To compare two methods, based on different approaches, for simultaneous determination of chlorpheniramine maleate (CHP) and dexamethasone (DX) in the presence of methyl and propyl paraben in phenadone syrup.Methods: The first method used, based on univariate calibration approach, was first derivative of the ratio spectrophotometry (DD1). The second method, which  is a multivariate calibration approach, was discrete wavelet transform followed by partial least squares method (DWT-PLS) which anticipated high predictive ability for the determination of both CHP and DX.Results: DD1 method failed to determine DX due to the absence of adequate zero crossing point while DWT-PLS method was successfully applied for the analysis of raw materials and the dosage form. For DD1 method, recovery of chlorpheniramine maleate in the dosage form was 100.33 ± 0.91 % while for DWT-PLS method, recovery of chlorpheniramine maleate and dexamethasone was 100.24 ± 1.21 and 99.99 ± 1.08 %, respectively. The proposed methods were validated using  standard addition technique and the results compared favorably with those obtained by a reference high performance liquid chromatography (HPLC) method.Conclusion: The findings of this work show the superiority of DWT-PLS over DD1 method in solving such complex mixtures, and would thus be suitable for use in quality control (QC) laboratories and pharmaceutical industry.Keywords: Quantitative analysis, Discrete wavelet transform, First derivative of ratio spectra, Chlorpheniramine maleate, Dexamethason

Artificial Neural Networks and Concentration Residual Augmented Classical Least Squares for the Simultaneous Determination of Diphenhydramine, Benzonatate, Guaifenesin and Phenylephrine in their Quaternary Mixture

Purpose: To develop two multivariate calibration methods for the simultaneous spectrophotometric determination of a quaternary mixture composed of diphenhydramine HCl, benzonatate, guaifenesin and phenylephrine HCl in Bronchofree ™ capsules in the ratio of 2.5 : 10 : 10 : 1, respectively.Methods: Novel artificial neural networks (ANNs) and concentration residual augmented classical least squares (CRACLS) methods were developed for the quantitative determination of the quaternary mixture. For proper analysis, a four-level, four-factor experimental design was established resulting in a training set of 16 mixtures containing different ratios of the four analytes. A validation set consisting of six mixtures was used to validate the prediction ability of the suggested models.Results: ANNs and CRACLS methods were successfully applied for the analysis of raw materials and capsules. For ANNs method, % recovery of diphenhydramine HCl, benzonatate, guaifenesin and phenylephrine HCl in the capsules was 102.21 ± 1.34, 100.30 ± 1.17, 99.31 ± 2.00 and 98.50 ± 1.27, respectively. On the other hand, % recovery of the four analytes by CRACLS was 99.84 ± 2.22, 100.07 ± 0.63, 98.37 ± 1.42 and 97.99 ± 0.96, respectively.Conclusion: The proposed methods can be applied for the quantitative determination of the four components without interference from excipients, thus obviating the need for preliminary extraction of analytes from the pharmaceutical formulation. The ability of the methods to deconvolute the highly overlapped UV spectra of the four components’ mixtures using low-cost and easy-to-handle instruments such as UV spectrophotometer is also an advantage.Keywords: Artificial neural networks, Concentration residual augmented classical least squares, Quaternary mixture, Simultaneous determinatio

Epithelioma of Malherbe: new ultrasound patterns

<p>Abstract</p> <p>Backround</p> <p>Calcifying epithelioma of Malherbe, or Pilomatricoma, is considered an uncommon cutaneous neoplasia, normally occurring in children as a solitary, firm, asymptomatic, hard, subcutaneous, slowly growing nodule on the face, neck, or proximal upper extremity. In literature, two Pilomatricoma ultrasound patterns are described: the totally calcified nodule and the hypoechoic nodule with internal calcific foci. High frequency ultrasound has not yet been applied for routine diagnosis of Pilomatricoma. The aim of the study was to retrospectively identify specific ultrasound features.</p> <p>Methods</p> <p>We retrieved 124 histologically Pilomatricoma cases: 28 patients with 32 lesions were preoperatively evaluated with ultrasound.</p> <p>Results</p> <p>22/32 have shown a solid formation, hypoechoic, with a sharp outline. Of these 22, 10 lesions were completely calcifying and 12 partially calcified. In 3/32 lesions with uncertain diagnosis, ultrasounds showed a complex/mixed pattern with pseudo-fluid areas and microspots. 7/32 lesions with US different diagnosis included 3 complex lesions, 2 cystic lesions and 2 solid nodular lesions.</p> <p>Conclusion</p> <p>In addition to well-known ultrasound patterns (completely calcified and partially calcified) we identified three new, not yet described, patterns that constitute the 31% of the cases: complex, pseudocistyc and pseudotumoral.</p

Development of Three Methods for Simultaneous Quantitative Determination of Chlorpheniramine Maleate and Dexamethasone in the Presence of Parabens in Oral Liquids

Purpose: To develop new selective, precise, and accurate methods for the simultaneous determination of chlorpheniramine maleate (CHP) and dexamethasone (DX) in the presence of methyl and propyl paraben in phenadone syrup.Methods: In the first two methods, the predictive abilities of principal component regression (PCR) and partial least squares (PLS), respectively, were examined for the analysis of the quaternary mixture. The third method, high performance thin layer chromatography (HPTLC)-densitometric method, was based on the separation of the mixture on silica gel plates using chloroform: methanol (93:7, v/v) as a mobile phase.Results: All the proposed methods were successfully applied to the analysis of raw materials and dosage form. For PCR method, recovery of chlorpheniramine maleate and dexamethasone in the dosage form was 98.89 ± 1.736 and 102.36 ± 1.86 %, respectively while for. PLS method, recovery of chlorpheniramine maleate and dexamethasone was 98.94 ± 1.69 and 102.33 ±1.84, respectively. On the other hand, recovery of the two analytes by HPTLC method was 100.72 ± 1.05 and 102.29 ± 3.98, respectively. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by a reported HPLC method.Conclusion: The proposed methods are fast, accurate and specific, and can be applied for the quantitative determination of the two analytes without interference from added excipient, thus obviating the need for preliminary extraction of analytes from the pharmaceutical formulation. Thus, they are suitable for use in quality control (QC) laboratories and pharmaceutical industryKeywords: Chlorpheniramine maleate, Dexamethasone, Principal component regression, Partial least squares, High performance thin layer chromatography, Excipient