The Experts below are selected from a list of 1950 Experts worldwide ranked by ideXlab platform

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

  • HPLC method development/validation and skin diffusion study of caffeine, Methyl Paraben and butyl Paraben as skin-diffusing model drugs.
    PloS one, 2021
    Co-Authors: Randa S H Mansour, Imad I Hamdan, Mutaz S H Salem, Enam A Khalil, Alsayed A Sallam
    Abstract:

    The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, Methyl Paraben and butyl Paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.

  • hplc method development validation and skin diffusion study of caffeine Methyl Paraben and butyl Paraben as skin diffusing model drugs
    PLOS ONE, 2021
    Co-Authors: Randa S H Mansour, Imad I Hamdan, Mutaz S H Salem, Enam A Khalil, Alsayed A Sallam
    Abstract:

    The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, Methyl Paraben and butyl Paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.

Randa S H Mansour - One of the best experts on this subject based on the ideXlab platform.

  • HPLC method development/validation and skin diffusion study of caffeine, Methyl Paraben and butyl Paraben as skin-diffusing model drugs.
    PloS one, 2021
    Co-Authors: Randa S H Mansour, Imad I Hamdan, Mutaz S H Salem, Enam A Khalil, Alsayed A Sallam
    Abstract:

    The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, Methyl Paraben and butyl Paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.

  • hplc method development validation and skin diffusion study of caffeine Methyl Paraben and butyl Paraben as skin diffusing model drugs
    PLOS ONE, 2021
    Co-Authors: Randa S H Mansour, Imad I Hamdan, Mutaz S H Salem, Enam A Khalil, Alsayed A Sallam
    Abstract:

    The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, Methyl Paraben and butyl Paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.

D. Olomolaiye - One of the best experts on this subject based on the ideXlab platform.

  • Practical and theoretical consideration of flow-through microcalorimetry: determination of "thermal volume" and its flow rate dependence
    Thermochimica Acta, 2003
    Co-Authors: Michael A. A. O'neill, A.e. Beezer, D. Olomolaiye, George J. Vine, Richard B. Kemp, Pedro L. O. Volpe, Denise A. Oliveira
    Abstract:

    Abstract The results have recently been reported of a preliminary study into the base catalysed hydrolysis of Methyl Paraben as a test and reference reaction for flow-through microcalorimeters. The values quoted for the rate constant and the molar enthalpy change are (3.15±0.11)×10−4 s−1 and −50.5±4.3 kJ mol−1, respectively. The present paper explains the results of further studies of the Methyl Paraben reaction and also describes some practical and theoretical considerations of flow microcalorimetric experiments. It is shown that experimental design (sample and reference arrangements) has a significant impact upon the derived data. Particular attention is paid to the theoretical range of values for the molar enthalpy change and the rate constant, for reactions that could be studied successfully by flow calorimetry.

  • the base catalysed hydrolysis of Methyl Paraben a test reaction for flow microcalorimeters used for determination of both kinetic and thermodynamic parameters
    Thermochimica Acta, 2003
    Co-Authors: Michael A A Oneill, A.e. Beezer, C. Labetoulle, L. Nicolaides, J.c. Mitchell, J.a. Orchard, J.a. Connor, R.b. Kemp, D. Olomolaiye
    Abstract:

    Abstract The results of an inter/intra-laboratory study into a test and reference reaction for isothermal microcalorimeters, the imidazole catalysed hydrolysis of triacetin, have been reported in a recent paper [Thermochim. Acta 380 (2001) 13]. The results and conclusions drawn from this study have been extended to a consideration of the need for a similar test and reference reaction for isothermal microcalorimeters operating in flow mode. This paper reports the findings of a preliminary inter/intra-laboratory study of the base catalysed hydrolysis of Methyl 4-hydroxy benzoate (Methyl Paraben) and its suitability as a test and reference reaction. The derived values for the hydrolysis reaction were (3.15±0.11)×10−4 s−1 and −50.5±4.3 kJ mol−1 for the rate constant and enthalpy, respectively. It is also reported how such a test and reference reaction can be used to validate the thermal output from a LKB 10-700-1 and Thermometric Thermal Activity Monitor (TAM) 2277-202 flow microcalorimeters.

  • The base catalysed hydrolysis of Methyl Paraben: a test reaction for flow microcalorimeters used for determination of both kinetic and thermodynamic parameters
    Thermochimica Acta, 2003
    Co-Authors: M.a.a. O’neill, A.e. Beezer, C. Labetoulle, L. Nicolaides, J.c. Mitchell, J.a. Orchard, J.a. Connor, R.b. Kemp, D. Olomolaiye
    Abstract:

    O'Neill, M. A. A., Beezer, A. E., Labetoulle, C., Nicolaides, L., Mitchell, J. C., Orchard, J. A., Connor, J. A., Kemp, R. B., Olomolaiye, D. (2003). The base catalysed hydrolysis of Methyl Paraben, a test reaction for flow microcalorimeters used for determination of both kinetic and thermodynamic parameters. ? Thermochimica Acta, 399, (1-2), 63-71.The results of an inter/intra-laboratory study into a test and reference reaction for isothermal microcalorimeters, the imidazole catalysed hydrolysis of triacetin, have been reported in a recent paper [Thermochim. Acta 380 (2001) 13]. The results and conclusions drawn from this study have been extended to a consideration of the need for a similar test and reference reaction for isothermal microcalorimeters operating in flow mode. This paper reports the findings of a preliminary inter/intra-laboratory study of the base catalysed hydrolysis of Methyl 4-hydroxy benzoate (Methyl Paraben) and its suitability as a test and reference reaction. The derived values for the hydrolysis reaction were (3.15?0.11)?10?4 s?1 and ?50.5?4.3 kJ mol?1 for the rate constant and enthalpy, respectively. It is also reported how such a test and reference reaction can be used to validate the thermal output from a LKB 10-700-1 and Thermometric Thermal Activity Monitor (TAM) 2277-202 flow microcalorimeters.Peer reviewe

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

  • HPLC method development/validation and skin diffusion study of caffeine, Methyl Paraben and butyl Paraben as skin-diffusing model drugs.
    PloS one, 2021
    Co-Authors: Randa S H Mansour, Imad I Hamdan, Mutaz S H Salem, Enam A Khalil, Alsayed A Sallam
    Abstract:

    The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, Methyl Paraben and butyl Paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.

  • hplc method development validation and skin diffusion study of caffeine Methyl Paraben and butyl Paraben as skin diffusing model drugs
    PLOS ONE, 2021
    Co-Authors: Randa S H Mansour, Imad I Hamdan, Mutaz S H Salem, Enam A Khalil, Alsayed A Sallam
    Abstract:

    The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, Methyl Paraben and butyl Paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.

Imad I Hamdan - One of the best experts on this subject based on the ideXlab platform.

  • HPLC method development/validation and skin diffusion study of caffeine, Methyl Paraben and butyl Paraben as skin-diffusing model drugs.
    PloS one, 2021
    Co-Authors: Randa S H Mansour, Imad I Hamdan, Mutaz S H Salem, Enam A Khalil, Alsayed A Sallam
    Abstract:

    The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, Methyl Paraben and butyl Paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.

  • hplc method development validation and skin diffusion study of caffeine Methyl Paraben and butyl Paraben as skin diffusing model drugs
    PLOS ONE, 2021
    Co-Authors: Randa S H Mansour, Imad I Hamdan, Mutaz S H Salem, Enam A Khalil, Alsayed A Sallam
    Abstract:

    The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, Methyl Paraben and butyl Paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.