Browsing by Author "Hassan, Nagiba Y"

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A Comparative Study of Spectrophotometric Methods Versus Chemometric Methods; An Application on a Pharmaceutical Binary Mixture of Ofloxacin and Dexamethasone
(3/17/2013) Saleh, Sarah S; Lotfy, Hayam M; Elgizawy, Samia M; Hassan, Nagiba Y
Aim: To conduct a comparative study between the smart novel ratio difference spectrophotometric method (RDSM) versus four spectrophotometric methods: first derivative spectrophotometry (D1), first derivative of the ratio spectra (1DD), isoabsorpative point (Aiso), ratio subtraction (RS), and two chemometric techniques based on principal component regression (PCR) and partial least-squares (PLS-1) for the determination of a binary mixture of Ofloxacin (OFX) and Dexamethasone (DXM). Study Design: The results obtained from the proposed methods were statistically compared to the reported HPLC method using student’s t-test, F-test and One way ANOVA. Methodology: (OFX) was determined by the application of direct spectrophotometry, by measuring its zero-order (D0) absorption spectra at its λmax = 296.6 nm. (DXM) was determined by (D1) at 227.1 nm. By applying (1DD), (DXM) was determined at 237.3. The total concentration of both (OFX + DXM) was determined at their isoabsorpative point λiso= 238.3 nm, then the concentration of (DXM) in mixtures were calculated by subtraction. (DXM) was determined using the (RS) method at its λmax = 239 nm. (DXM) was determined using (RDSM) by measuring amplitude difference at two selected wavelengths (248.4 and 290 nm). A concentration of 10 µg.mL-1 of OFX was used as a divisor. The linearity range was found to be (1-10 µg.mL-1) and (2-14 µg.mL-1) for OFX and DXM respectively. Results: The recovery percentage for OFX was found to be 100.07 ±0.65 and for DXM was found to be 100.41 ±0.84, 100.15 ±0.97, 100.14 ±0.91, 100.54 ±0.75 and 100.11 ±.66 for the five methods, respectively. Conclusion: The novel method showed advantages over the other proposed methods regarding simplicity, minimal data manipulation and maximum reproducibility and robustness; which enabled the analysis of binary mixtures with overlapped spectra for routine quality control testing with quite satisfactory and in lower cost.
A Comparative Study of the Novel Ratio Difference Method versus Conventional Spectrophotometric Techniques for the Analysis of Binary Mixture with Overlapped Spectra
(Scientific Research Publishing, 2012) Elgizawy, Samia M.; Hassan, Nagiba Y; Saleh, Sarah S; Lotfy, Hayam M
The smart novel ratio difference spectrophotometric method was developed and validated for the determination of a binary mixture of Sodium cromoglicate (SCG) and Fluorometholone (FLU) in presence of benzalkonium chloride without prior separation. The results were compared to that of the conventional methods (dual wavelength and first derivative of ratio spectra). The suggested methods were validated in compliance with the ICH guidelines and were successfully applied for determination of SCG and FLU in their laboratory prepared mixtures and commercial ophthalmic solution. The novel method showed significant advantages over the conventional methods regarding simplicity, minimal data manipulation and maximum reproducibility and robustness; which enabled the analysis of binary mixtures with overlapped spectra for routine quality control testing with quite satisfactory.
Univariate versus Multivariate Spectrophotometric Methods for Simultaneous Determination of Complex Binary Mixtures with Overlapped Spectra: A Comparative Study
(Taylor & Francis, 2013-09) Elgizawy, Samia M.; Hassan, Nagiba Y; Saleh, Sarah S.; Lotfy, Hayam M
Two novel simple and accurate univariate spectrophotometric methods were described for the determination of a binary mixture of Sodium cromoglicate (SCG) and Fluorometholone (FLU) namely; ratio subtraction coupled with extended ratio subtraction (RS-EXRSM) and constant center (CCSM) spectrophotometric methods. The methods were able to recover the zero order absorption spectra of both drugs from their binary mixture through simple mathematical calculations. The linearity ranges were found to be (2.5–25 µg/mL) and (4- 25 µg/mL) for SCG and FLU, respectively. A comparative study was conducted between the proposed univariate methods versus multivariate ones, based on using principle component regression (PCR) and partial least squares (PLS-2). Upon applying the methods for the determination of SCG and FLU in laboratory prepared mixtures, the (CCSM and PLS-2) proved to be of higher predictive ability rather than (RS-EXRSM and PCR) in prediction of mixtures containing low concentration of one of the components. The proposed methods were validated in compliance with the ICH guidelines. These methods could be alternative to different HPLC techniques in quality control laboratories lacking the required facilities for those expensive techniques