The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform

Hesham Salem - One of the best experts on this subject based on the ideXlab platform.

  • Computation of geometric representation of novel spectrophotometric methods used for the analysis of minor components in pharmaceutical preparations.
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2015
    Co-Authors: Hayam M Lotfy, Sarah S Saleh, Nagiba Y Hassan, Hesham Salem
    Abstract:

    Novel spectrophotometric methods were applied for the determination of the minor component Tetryzoline HCl (TZH) in its ternary mixture with ofloxacin (OFX) and prednisolone acetate (PA) in the ratio of (1:5:7.5), and in its binary mixture with sodium cromoglicate (SCG) in the ratio of (1:80). The novel spectrophotometric methods determined the minor component (TZH) successfully in the two selected mixtures by computing the geometrical relationship of either standard addition or subtraction. The novel spectrophotometric methods are: geometrical amplitude modulation (GAM), geometrical induced amplitude modulation (GIAM), ratio H-point standard addition method (RHPSAM) and compensated area under the curve (CAUC). The proposed methods were successfully applied for the determination of the minor component TZH below its concentration range. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories.

  • Column Performance Study of Different Variants of Liquid Chromatographic Technique: An Application on Pharmaceutical Ternary Mixtures Containing Tetryzoline
    Journal of chromatographic science, 2014
    Co-Authors: Hesham Salem, Hayam M Lotfy, Nagiba Y Hassan, Sarah S Saleh
    Abstract:

    High-performance liquid chromatography (HPLC), ultra-performance liquid chromatography (UPLC) and rapid resolution liquid chromatographic (RRLC) methods have been developed and validated for the separation and quantitation of both or either of two ternary mixtures present in ophthalmic solutions. The first mixture contains chloramphenicol, dexamethasone sodium phosphate and Tetryzoline HCl (TZH); while the second one contains ofloxacin, prednisolone acetate and TZH. Both preparations contain benzalkonium chloride as a preservative. The columns used were a HPLC column (C18 5 µm particle size), a RRLC column (C18 2.6 µm particle size) and a UPLC column (C18 1.7 µm particle size). A comparative study was conducted to illustrate the effect of the change in column particle size and dimensions on the other chromatographic conditions, backpressure and the separation of both ternary mixtures. The methods were validated as per ICH guidelines where accuracy, repeatability, interday precision and robustness were found to be within the acceptable limits. The RRLC column provided shorter run time and better resolution than HPLC, while the UPLC column gave the shortest run time for all columns. The RRLC column resulted in minimum backpressure, so it could be used with any HPLC instrument, which makes the method more practical and economic. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  • A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: derivative spectrophotometry versus wavelet transform.
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2014
    Co-Authors: Hesham Salem, Hayam M Lotfy, Nagiba Y Hassan, Mohamed B. El-zeiny, Sarah S Saleh
    Abstract:

    This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.

  • a comparative study of novel spectrophotometric methods based on isosbestic points application on a pharmaceutical ternary mixture
    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2014
    Co-Authors: Hayam M Lotfy, Sarah S Saleh, Nagiba Y Hassan, Hesham Salem
    Abstract:

    This work represents the application of the isosbestic points present in different absorption spectra. Three novel spectrophotometric methods were developed, the first method is the absorption subtraction method (AS) utilizing the isosbestic point in zero-order absorption spectra; the second method is the amplitude modulation method (AM) utilizing the isosbestic point in ratio spectra; and third method is the amplitude summation method (A-Sum) utilizing the isosbestic point in derivative spectra. The three methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and Tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The components at the isosbestic point were determined using the corresponding unified regression equation at this point with no need for a complementary method. The obtained results were statistically compared to each other and to that of the developed PLS model. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  • A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2014
    Co-Authors: Sarah S Saleh, Hayam M Lotfy, Nagiba Y Hassan, Hesham Salem
    Abstract:

    This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and Tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision.

Sarah S Saleh - One of the best experts on this subject based on the ideXlab platform.

  • Computation of geometric representation of novel spectrophotometric methods used for the analysis of minor components in pharmaceutical preparations.
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2015
    Co-Authors: Hayam M Lotfy, Sarah S Saleh, Nagiba Y Hassan, Hesham Salem
    Abstract:

    Novel spectrophotometric methods were applied for the determination of the minor component Tetryzoline HCl (TZH) in its ternary mixture with ofloxacin (OFX) and prednisolone acetate (PA) in the ratio of (1:5:7.5), and in its binary mixture with sodium cromoglicate (SCG) in the ratio of (1:80). The novel spectrophotometric methods determined the minor component (TZH) successfully in the two selected mixtures by computing the geometrical relationship of either standard addition or subtraction. The novel spectrophotometric methods are: geometrical amplitude modulation (GAM), geometrical induced amplitude modulation (GIAM), ratio H-point standard addition method (RHPSAM) and compensated area under the curve (CAUC). The proposed methods were successfully applied for the determination of the minor component TZH below its concentration range. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories.

  • Column Performance Study of Different Variants of Liquid Chromatographic Technique: An Application on Pharmaceutical Ternary Mixtures Containing Tetryzoline
    Journal of chromatographic science, 2014
    Co-Authors: Hesham Salem, Hayam M Lotfy, Nagiba Y Hassan, Sarah S Saleh
    Abstract:

    High-performance liquid chromatography (HPLC), ultra-performance liquid chromatography (UPLC) and rapid resolution liquid chromatographic (RRLC) methods have been developed and validated for the separation and quantitation of both or either of two ternary mixtures present in ophthalmic solutions. The first mixture contains chloramphenicol, dexamethasone sodium phosphate and Tetryzoline HCl (TZH); while the second one contains ofloxacin, prednisolone acetate and TZH. Both preparations contain benzalkonium chloride as a preservative. The columns used were a HPLC column (C18 5 µm particle size), a RRLC column (C18 2.6 µm particle size) and a UPLC column (C18 1.7 µm particle size). A comparative study was conducted to illustrate the effect of the change in column particle size and dimensions on the other chromatographic conditions, backpressure and the separation of both ternary mixtures. The methods were validated as per ICH guidelines where accuracy, repeatability, interday precision and robustness were found to be within the acceptable limits. The RRLC column provided shorter run time and better resolution than HPLC, while the UPLC column gave the shortest run time for all columns. The RRLC column resulted in minimum backpressure, so it could be used with any HPLC instrument, which makes the method more practical and economic. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  • A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: derivative spectrophotometry versus wavelet transform.
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2014
    Co-Authors: Hesham Salem, Hayam M Lotfy, Nagiba Y Hassan, Mohamed B. El-zeiny, Sarah S Saleh
    Abstract:

    This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.

  • a comparative study of novel spectrophotometric methods based on isosbestic points application on a pharmaceutical ternary mixture
    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2014
    Co-Authors: Hayam M Lotfy, Sarah S Saleh, Nagiba Y Hassan, Hesham Salem
    Abstract:

    This work represents the application of the isosbestic points present in different absorption spectra. Three novel spectrophotometric methods were developed, the first method is the absorption subtraction method (AS) utilizing the isosbestic point in zero-order absorption spectra; the second method is the amplitude modulation method (AM) utilizing the isosbestic point in ratio spectra; and third method is the amplitude summation method (A-Sum) utilizing the isosbestic point in derivative spectra. The three methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and Tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The components at the isosbestic point were determined using the corresponding unified regression equation at this point with no need for a complementary method. The obtained results were statistically compared to each other and to that of the developed PLS model. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  • A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2014
    Co-Authors: Sarah S Saleh, Hayam M Lotfy, Nagiba Y Hassan, Hesham Salem
    Abstract:

    This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and Tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision.

Hayam M Lotfy - One of the best experts on this subject based on the ideXlab platform.

  • Computation of geometric representation of novel spectrophotometric methods used for the analysis of minor components in pharmaceutical preparations.
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2015
    Co-Authors: Hayam M Lotfy, Sarah S Saleh, Nagiba Y Hassan, Hesham Salem
    Abstract:

    Novel spectrophotometric methods were applied for the determination of the minor component Tetryzoline HCl (TZH) in its ternary mixture with ofloxacin (OFX) and prednisolone acetate (PA) in the ratio of (1:5:7.5), and in its binary mixture with sodium cromoglicate (SCG) in the ratio of (1:80). The novel spectrophotometric methods determined the minor component (TZH) successfully in the two selected mixtures by computing the geometrical relationship of either standard addition or subtraction. The novel spectrophotometric methods are: geometrical amplitude modulation (GAM), geometrical induced amplitude modulation (GIAM), ratio H-point standard addition method (RHPSAM) and compensated area under the curve (CAUC). The proposed methods were successfully applied for the determination of the minor component TZH below its concentration range. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories.

  • Column Performance Study of Different Variants of Liquid Chromatographic Technique: An Application on Pharmaceutical Ternary Mixtures Containing Tetryzoline
    Journal of chromatographic science, 2014
    Co-Authors: Hesham Salem, Hayam M Lotfy, Nagiba Y Hassan, Sarah S Saleh
    Abstract:

    High-performance liquid chromatography (HPLC), ultra-performance liquid chromatography (UPLC) and rapid resolution liquid chromatographic (RRLC) methods have been developed and validated for the separation and quantitation of both or either of two ternary mixtures present in ophthalmic solutions. The first mixture contains chloramphenicol, dexamethasone sodium phosphate and Tetryzoline HCl (TZH); while the second one contains ofloxacin, prednisolone acetate and TZH. Both preparations contain benzalkonium chloride as a preservative. The columns used were a HPLC column (C18 5 µm particle size), a RRLC column (C18 2.6 µm particle size) and a UPLC column (C18 1.7 µm particle size). A comparative study was conducted to illustrate the effect of the change in column particle size and dimensions on the other chromatographic conditions, backpressure and the separation of both ternary mixtures. The methods were validated as per ICH guidelines where accuracy, repeatability, interday precision and robustness were found to be within the acceptable limits. The RRLC column provided shorter run time and better resolution than HPLC, while the UPLC column gave the shortest run time for all columns. The RRLC column resulted in minimum backpressure, so it could be used with any HPLC instrument, which makes the method more practical and economic. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  • A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: derivative spectrophotometry versus wavelet transform.
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2014
    Co-Authors: Hesham Salem, Hayam M Lotfy, Nagiba Y Hassan, Mohamed B. El-zeiny, Sarah S Saleh
    Abstract:

    This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.

  • a comparative study of novel spectrophotometric methods based on isosbestic points application on a pharmaceutical ternary mixture
    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2014
    Co-Authors: Hayam M Lotfy, Sarah S Saleh, Nagiba Y Hassan, Hesham Salem
    Abstract:

    This work represents the application of the isosbestic points present in different absorption spectra. Three novel spectrophotometric methods were developed, the first method is the absorption subtraction method (AS) utilizing the isosbestic point in zero-order absorption spectra; the second method is the amplitude modulation method (AM) utilizing the isosbestic point in ratio spectra; and third method is the amplitude summation method (A-Sum) utilizing the isosbestic point in derivative spectra. The three methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and Tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The components at the isosbestic point were determined using the corresponding unified regression equation at this point with no need for a complementary method. The obtained results were statistically compared to each other and to that of the developed PLS model. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  • A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2014
    Co-Authors: Sarah S Saleh, Hayam M Lotfy, Nagiba Y Hassan, Hesham Salem
    Abstract:

    This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and Tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision.

Nagiba Y Hassan - One of the best experts on this subject based on the ideXlab platform.

  • Computation of geometric representation of novel spectrophotometric methods used for the analysis of minor components in pharmaceutical preparations.
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2015
    Co-Authors: Hayam M Lotfy, Sarah S Saleh, Nagiba Y Hassan, Hesham Salem
    Abstract:

    Novel spectrophotometric methods were applied for the determination of the minor component Tetryzoline HCl (TZH) in its ternary mixture with ofloxacin (OFX) and prednisolone acetate (PA) in the ratio of (1:5:7.5), and in its binary mixture with sodium cromoglicate (SCG) in the ratio of (1:80). The novel spectrophotometric methods determined the minor component (TZH) successfully in the two selected mixtures by computing the geometrical relationship of either standard addition or subtraction. The novel spectrophotometric methods are: geometrical amplitude modulation (GAM), geometrical induced amplitude modulation (GIAM), ratio H-point standard addition method (RHPSAM) and compensated area under the curve (CAUC). The proposed methods were successfully applied for the determination of the minor component TZH below its concentration range. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories.

  • Column Performance Study of Different Variants of Liquid Chromatographic Technique: An Application on Pharmaceutical Ternary Mixtures Containing Tetryzoline
    Journal of chromatographic science, 2014
    Co-Authors: Hesham Salem, Hayam M Lotfy, Nagiba Y Hassan, Sarah S Saleh
    Abstract:

    High-performance liquid chromatography (HPLC), ultra-performance liquid chromatography (UPLC) and rapid resolution liquid chromatographic (RRLC) methods have been developed and validated for the separation and quantitation of both or either of two ternary mixtures present in ophthalmic solutions. The first mixture contains chloramphenicol, dexamethasone sodium phosphate and Tetryzoline HCl (TZH); while the second one contains ofloxacin, prednisolone acetate and TZH. Both preparations contain benzalkonium chloride as a preservative. The columns used were a HPLC column (C18 5 µm particle size), a RRLC column (C18 2.6 µm particle size) and a UPLC column (C18 1.7 µm particle size). A comparative study was conducted to illustrate the effect of the change in column particle size and dimensions on the other chromatographic conditions, backpressure and the separation of both ternary mixtures. The methods were validated as per ICH guidelines where accuracy, repeatability, interday precision and robustness were found to be within the acceptable limits. The RRLC column provided shorter run time and better resolution than HPLC, while the UPLC column gave the shortest run time for all columns. The RRLC column resulted in minimum backpressure, so it could be used with any HPLC instrument, which makes the method more practical and economic. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  • A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: derivative spectrophotometry versus wavelet transform.
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2014
    Co-Authors: Hesham Salem, Hayam M Lotfy, Nagiba Y Hassan, Mohamed B. El-zeiny, Sarah S Saleh
    Abstract:

    This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.

  • a comparative study of novel spectrophotometric methods based on isosbestic points application on a pharmaceutical ternary mixture
    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2014
    Co-Authors: Hayam M Lotfy, Sarah S Saleh, Nagiba Y Hassan, Hesham Salem
    Abstract:

    This work represents the application of the isosbestic points present in different absorption spectra. Three novel spectrophotometric methods were developed, the first method is the absorption subtraction method (AS) utilizing the isosbestic point in zero-order absorption spectra; the second method is the amplitude modulation method (AM) utilizing the isosbestic point in ratio spectra; and third method is the amplitude summation method (A-Sum) utilizing the isosbestic point in derivative spectra. The three methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and Tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The components at the isosbestic point were determined using the corresponding unified regression equation at this point with no need for a complementary method. The obtained results were statistically compared to each other and to that of the developed PLS model. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

  • A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures
    Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2014
    Co-Authors: Sarah S Saleh, Hayam M Lotfy, Nagiba Y Hassan, Hesham Salem
    Abstract:

    This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and Tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision.

A. Ziegler - One of the best experts on this subject based on the ideXlab platform.

  • Nasal decongestion with imidazoline derivatives: acoustic rhinometry measurements.
    European journal of clinical pharmacology, 1999
    Co-Authors: W. Hochban, H. Althoff, A. Ziegler
    Abstract:

    The objective of this single-blind study was to establish whether there are any differences between conventional imidazoline-containing nasal drops with regard to duration of action and decongestion potential. Six different substances were each administered to 108 healthy volunteers (nine groups of 12 adults), respectively, in the concentration recommended for adults (and two also in that recommended for infants) over a period of 8 h in comparison with 0.9% NaCl. The volumetric measurement of the nasal lumen was conducted by means of acoustic rhinometry (Rhinoklack). The decongestive effect of all imidazoline preparations set in relatively uniformly, without any appreciable differences. After 20 min all the products exhibited approximately 60% of their maximum decongestive effect, which was achieved after approximately 40 min, having produced an increase in volume of approximately 20%. In contrast, in terms of duration of action, considerable differences between the individual products were to be discerned: indanazoline 0.118%, naphazoline 0.02% and Tetryzoline 0.1% had no effect whatsoever after 4 h. Oxymetazoline 0.05% and 0.01%, xylometazoline 0.025% and 0.1%, and tramazoline 0.1264% still had an appreciable effect after 4 h, while after 8 h only oxymetazoline 0.05% and 0.01% still had a relevant decongestive effect. A rebound effect associated with reactive hyperaemia was observed after 8 h in all short-acting products (indanazoline, naphazoline, Tetryzoline and tramazoline), which in the case of indanazoline was even associated with a reduction in the nasal lumen. Interestingly, there were no differences between the xylometazoline and oxymetazoline concentrations recommended for adults and those for infants in terms of efficacy. The low-dose concentrations of the preparations for infants appear to be sufficient to produce a satisfactory therapeutic effect.

  • Nasal decongestion with imidazoline derivatives: acoustic rhinometry measurements
    European Journal of Clinical Pharmacology, 1999
    Co-Authors: W. Hochban, H. Althoff, A. Ziegler
    Abstract:

    Objective : The objective of this single-blind study was to establish whether there are any differences between conventional imidazoline-containing nasal drops with regard to duration of action and decongestion potential. Methods : Six different substances were each administered to 108 healthy volunteers (nine groups of 12 adults), respectively, in the concentration recommended for adults (and two also in that recommended for infants) over a period of 8 h in comparison with 0.9% NaCl. The volumetric measurement of the nasal lumen was conducted by means of acoustic rhinometry (Rhinoklack). Results : The decongestive effect of all imidazoline preparations set in relatively uniformly, without any appreciable differences. After 20 min all the products exhibited approximately 60% of their maximum decongestive effect, which was achieved after approximately 40 min, having produced an increase in volume of approximately 20%. In contrast, in terms of duration of action, considerable differences between the individual products were to be discerned: indanazoline 0.118%, naphazoline 0.02% and Tetryzoline 0.1% had no effect whatsoever after 4 h. Oxymetazoline 0.05% and 0.01%, xylometazoline 0.025% and 0.1%, and tramazoline 0.1264% still had an appreciable effect after 4 h, while after 8 h only oxymetazoline 0.05% and 0.01% still had a relevant decongestive effect. A rebound effect associated with reactive hyperaemia was observed after 8 h in all short-acting products (indanazoline, naphazoline, Tetryzoline and tramazoline), which in the case of indanazoline was even associated with a reduction in the nasal lumen. Interestingly, there were no differences between the xylometazoline and oxymetazoline concentrations recommended for adults and those for infants in terms of efficacy. The low-dose concentrations of the preparations for infants appear to be sufficient to produce a satisfactory therapeutic effect.