Nouf Aloudah - Academia.edu (original) (raw)
Papers by Nouf Aloudah
International Journal of Pharmaceutics
Polyethylcyanoacrylate (PECA) nanoparticles (NPs) have been employed as biodegradable polymeric c... more Polyethylcyanoacrylate (PECA) nanoparticles (NPs) have been employed as biodegradable polymeric carriers for oral (PO) delivery of ketorolac. The nanoparticles were prepared by polymerization technique at room temperature in a continuous aqueous phase at pH 2.5. This polymerization technique was able to hold 76-96% of ketorolac and the drug loading was a monomer concentration dependent. The feasibility of PECA NPs as PO controlled drug delivery systems of ketorolac was investigated in two groups of rats which were given orally either ketorolac tromethamine solution (1.5 mg/kg) or the selected ketorolac NPs aqueous dispersion (1.6 mg/kg). Ketorolac plasma concentrations were measured by a new fully validated specific, precise and accurate ultra-performance liquid chromatography tandem mass spectrometry (UPLC MS/MS) assay. The detection was performed on Waters TQ detector via negative electrospray ionization in a multiple reaction monitoring mode. Linear response (r(2)> or =0.995) ...
Biomedical Chromatography
Warfarin is routinely monitored by assessing its pharmacologic effects on the international norma... more Warfarin is routinely monitored by assessing its pharmacologic effects on the international normalized ratio. However, having a patient with INR not responding to increasing warfarin dose mandates a direct measurement of warfarin concentrations (total and free) for better patient clinical management of warfarin therapy. Therefore, a new fully validated specific, precise and accurate ultra-performance liquid chromatography tandem mass spectrometry was developed for the determination of free and total warfarin in human plasma. Free warfarin was measured in plasma filtrate, prepared by ultrafiltration, and sample pretreatment involved protein precipitation with acetonitrile. Linear response (r(2) ≥0.99) was observed over the studied range of free and total warfarin, with the lower limit of detection of 0.25 ng/mL. The intra- and inter-day precision (relative standard deviation) values were <10% and the accuracy (relative error) was ≤6.6 for free and total warfarin. There was no sign...
Journal of Liquid Chromatography & Related Technologies
This work describes a precise, simple, and accurate HPLC method for the determination of fluconaz... more This work describes a precise, simple, and accurate HPLC method for the determination of fluconazole in plasma samples with enough sensitivity to monitor patients suffering from early septic shock for a month. The separation was done using an HPLC system with UV absorbance detector (set at 262 nm). It was performed using a m Bondapak C 18 column (3.9 Â 150 mm 2) packed with 10 mm spherical particles. The mobile phase consisted of acetonitrile (20%) in 0.05 M ammonium acetate containing 0.1% triethylamine; acetic acid was used to adjust the pH to 7. Sample run time was 15 min. Metoclopramide was used as the assay internal standard (IS). Using the chromatographic conditions described, fluconazole and metoclopramide were well resolved with mean retention times of 6.7 and 10.2 min, respectively. Linear response (r . 0.996) was observed over the range of 0.2– 15 mg/mL of fluconazole. There was no significant difference (p . 0.05) between inter-and intra-day studies for fluconazole. The m...
Journal of Liquid Chromatography & Related Technologies, 2005
This work describes a precise, simple, and accurate HPLC method for the determination of fluconaz... more This work describes a precise, simple, and accurate HPLC method for the determination of fluconazole in plasma samples with enough sensitivity to monitor patients suffering from early septic shock for a month. The separation was done using an HPLC system with UV absorbance detector (set at 262 nm). It was performed using a m Bondapak C 18 column (3.9 Â 150 mm 2 ) packed with 10 mm spherical particles. The mobile phase consisted of acetonitrile (20%) in 0.05 M ammonium acetate containing 0.1% triethylamine; acetic acid was used to adjust the pH to 7. Sample run time was 15 min. Metoclopramide was used as the assay internal standard (IS). Using the chromatographic conditions described, fluconazole and metoclopramide were well resolved with mean retention times of 6.7 and 10.2 min, respectively. Linear response (r . 0.996) was observed over the range of 0.2-15 mg/mL of fluconazole. There was no significant difference ( p . 0.05) between inter-and intra-day studies for fluconazole. The mean relative standard deviation (RSD%) of the results of within-day precision and accuracy of the drug was 7.6%, which confirmed the reproducibility of the assay method. The applicability of the assay was demonstrated in measuring fluconazole pharmacokinetics in human plasma after daily intravenous infusion of 200 mg fluconazole to patient with early septic shock. Re-analysis of samples several weeks after the initial analysis showed no loss in fluconazole. Patient with early septic shock showed a mean t 1/2 of Address correspondence to Mahasen A. Radwan,
Biomedical Chromatography, 2012
Warfarin is routinely monitored by assessing its pharmacologic effects on the international norma... more Warfarin is routinely monitored by assessing its pharmacologic effects on the international normalized ratio. However, having a patient with INR not responding to increasing warfarin dose mandates a direct measurement of warfarin concentrations (total and free) for better patient clinical management of warfarin therapy. Therefore, a new fully validated specific, precise and accurate ultra-performance liquid chromatography tandem mass spectrometry was developed for the determination of free and total warfarin in human plasma. Free warfarin was measured in plasma filtrate, prepared by ultrafiltration, and sample pretreatment involved protein precipitation with acetonitrile. Linear response (r 2 ≥ 0.99) was observed over the studied range of free and total warfarin, with the lower limit of detection of 0.25 ng/mL. The intra-and inter-day precision (relative standard deviation) values were <10% and the accuracy (relative error) was ≤6.6 for free and total warfarin. There was no significant difference (p > 0.05) between inter-and intra-day studies for the free and total warfarin, which confirmed the reproducibility of the assay method. The mean extraction efficiency was 88.6-107.2% of free and total warfarin. The assay was sensitive to follow warfarin pharmacokinetics (free and total) in a patient with resistance to warfarin up to 24 h after a daily dose of warfarin.
Therapeutic Drug Monitoring, 2011
There is no evidence that the use of contrast media (CM) in diabetic patients with serum creatini... more There is no evidence that the use of contrast media (CM) in diabetic patients with serum creatinine &amp;amp;amp;lt;130 μmole/L leads to metformin accumulation and subsequent lactic acidosis. Therefore, the objective of this investigation was to monitor cardiac patients for the effects of CM on their metformin plasma concentration and serum creatinine clearance (ClCr). Metformin plasma concentrations were measured by a new, fully validated specific, precise, and accurate ultra-high-performance liquid chromatography tandem mass-spectrometric assay. The detection was performed using positive electrospray ionization in the multiple reaction monitoring mode. Fifty patients with serum creatinine levels &amp;amp;amp;lt;130 μmole/L were monitored for the effect of CM exposure on metformin concentration and ClCr. Pharmacokinetic parameters were calculated in 8 of these patients, and metformin accumulation was monitored in 10 patients before and after their exposure to CM. Linear response (r ≥ 0.998) was observed over the range of 5-2000 ng/mL of metformin, with the lower limit of quantification of 2.3 ng/mL. The intraday and interday precision (relative standard deviation) values were &amp;amp;amp;lt;13%, and the accuracy (relative error) was &amp;amp;amp;lt;-10% for metformin concentrations. The assay was sensitive to follow the pharmacokinetics of metformin in humans during a dosing interval after an oral dose at steady state. Metformin pharmacokinetic parameters were estimated in 8 patients exposed to CM. The mean C(max) of 1.9 ± 0.6 mg/L was attained at 4.1 ± 1.9 hours. There was no evidence of any drug accumulation or altered elimination due to the exposure to CM in the current population. ClCr showed no significant difference (P &amp;amp;amp;gt; 0.05) before (92.8 ± 11.3 mL/min) and after 48 hours (90.5 ± 10.5 mL/min) of exposure to CM. Our data suggest that the recommendation to withhold metformin in diabetic patients during CM exposure could be revised to withholding the drug only in patients with moderate to severe renal dysfunction.
International Journal of Pharmaceutics
Polyethylcyanoacrylate (PECA) nanoparticles (NPs) have been employed as biodegradable polymeric c... more Polyethylcyanoacrylate (PECA) nanoparticles (NPs) have been employed as biodegradable polymeric carriers for oral (PO) delivery of ketorolac. The nanoparticles were prepared by polymerization technique at room temperature in a continuous aqueous phase at pH 2.5. This polymerization technique was able to hold 76-96% of ketorolac and the drug loading was a monomer concentration dependent. The feasibility of PECA NPs as PO controlled drug delivery systems of ketorolac was investigated in two groups of rats which were given orally either ketorolac tromethamine solution (1.5 mg/kg) or the selected ketorolac NPs aqueous dispersion (1.6 mg/kg). Ketorolac plasma concentrations were measured by a new fully validated specific, precise and accurate ultra-performance liquid chromatography tandem mass spectrometry (UPLC MS/MS) assay. The detection was performed on Waters TQ detector via negative electrospray ionization in a multiple reaction monitoring mode. Linear response (r(2)> or =0.995) ...
Biomedical Chromatography
Warfarin is routinely monitored by assessing its pharmacologic effects on the international norma... more Warfarin is routinely monitored by assessing its pharmacologic effects on the international normalized ratio. However, having a patient with INR not responding to increasing warfarin dose mandates a direct measurement of warfarin concentrations (total and free) for better patient clinical management of warfarin therapy. Therefore, a new fully validated specific, precise and accurate ultra-performance liquid chromatography tandem mass spectrometry was developed for the determination of free and total warfarin in human plasma. Free warfarin was measured in plasma filtrate, prepared by ultrafiltration, and sample pretreatment involved protein precipitation with acetonitrile. Linear response (r(2) ≥0.99) was observed over the studied range of free and total warfarin, with the lower limit of detection of 0.25 ng/mL. The intra- and inter-day precision (relative standard deviation) values were <10% and the accuracy (relative error) was ≤6.6 for free and total warfarin. There was no sign...
Journal of Liquid Chromatography & Related Technologies
This work describes a precise, simple, and accurate HPLC method for the determination of fluconaz... more This work describes a precise, simple, and accurate HPLC method for the determination of fluconazole in plasma samples with enough sensitivity to monitor patients suffering from early septic shock for a month. The separation was done using an HPLC system with UV absorbance detector (set at 262 nm). It was performed using a m Bondapak C 18 column (3.9 Â 150 mm 2) packed with 10 mm spherical particles. The mobile phase consisted of acetonitrile (20%) in 0.05 M ammonium acetate containing 0.1% triethylamine; acetic acid was used to adjust the pH to 7. Sample run time was 15 min. Metoclopramide was used as the assay internal standard (IS). Using the chromatographic conditions described, fluconazole and metoclopramide were well resolved with mean retention times of 6.7 and 10.2 min, respectively. Linear response (r . 0.996) was observed over the range of 0.2– 15 mg/mL of fluconazole. There was no significant difference (p . 0.05) between inter-and intra-day studies for fluconazole. The m...
Journal of Liquid Chromatography & Related Technologies, 2005
This work describes a precise, simple, and accurate HPLC method for the determination of fluconaz... more This work describes a precise, simple, and accurate HPLC method for the determination of fluconazole in plasma samples with enough sensitivity to monitor patients suffering from early septic shock for a month. The separation was done using an HPLC system with UV absorbance detector (set at 262 nm). It was performed using a m Bondapak C 18 column (3.9 Â 150 mm 2 ) packed with 10 mm spherical particles. The mobile phase consisted of acetonitrile (20%) in 0.05 M ammonium acetate containing 0.1% triethylamine; acetic acid was used to adjust the pH to 7. Sample run time was 15 min. Metoclopramide was used as the assay internal standard (IS). Using the chromatographic conditions described, fluconazole and metoclopramide were well resolved with mean retention times of 6.7 and 10.2 min, respectively. Linear response (r . 0.996) was observed over the range of 0.2-15 mg/mL of fluconazole. There was no significant difference ( p . 0.05) between inter-and intra-day studies for fluconazole. The mean relative standard deviation (RSD%) of the results of within-day precision and accuracy of the drug was 7.6%, which confirmed the reproducibility of the assay method. The applicability of the assay was demonstrated in measuring fluconazole pharmacokinetics in human plasma after daily intravenous infusion of 200 mg fluconazole to patient with early septic shock. Re-analysis of samples several weeks after the initial analysis showed no loss in fluconazole. Patient with early septic shock showed a mean t 1/2 of Address correspondence to Mahasen A. Radwan,
Biomedical Chromatography, 2012
Warfarin is routinely monitored by assessing its pharmacologic effects on the international norma... more Warfarin is routinely monitored by assessing its pharmacologic effects on the international normalized ratio. However, having a patient with INR not responding to increasing warfarin dose mandates a direct measurement of warfarin concentrations (total and free) for better patient clinical management of warfarin therapy. Therefore, a new fully validated specific, precise and accurate ultra-performance liquid chromatography tandem mass spectrometry was developed for the determination of free and total warfarin in human plasma. Free warfarin was measured in plasma filtrate, prepared by ultrafiltration, and sample pretreatment involved protein precipitation with acetonitrile. Linear response (r 2 ≥ 0.99) was observed over the studied range of free and total warfarin, with the lower limit of detection of 0.25 ng/mL. The intra-and inter-day precision (relative standard deviation) values were <10% and the accuracy (relative error) was ≤6.6 for free and total warfarin. There was no significant difference (p > 0.05) between inter-and intra-day studies for the free and total warfarin, which confirmed the reproducibility of the assay method. The mean extraction efficiency was 88.6-107.2% of free and total warfarin. The assay was sensitive to follow warfarin pharmacokinetics (free and total) in a patient with resistance to warfarin up to 24 h after a daily dose of warfarin.
Therapeutic Drug Monitoring, 2011
There is no evidence that the use of contrast media (CM) in diabetic patients with serum creatini... more There is no evidence that the use of contrast media (CM) in diabetic patients with serum creatinine &amp;amp;amp;lt;130 μmole/L leads to metformin accumulation and subsequent lactic acidosis. Therefore, the objective of this investigation was to monitor cardiac patients for the effects of CM on their metformin plasma concentration and serum creatinine clearance (ClCr). Metformin plasma concentrations were measured by a new, fully validated specific, precise, and accurate ultra-high-performance liquid chromatography tandem mass-spectrometric assay. The detection was performed using positive electrospray ionization in the multiple reaction monitoring mode. Fifty patients with serum creatinine levels &amp;amp;amp;lt;130 μmole/L were monitored for the effect of CM exposure on metformin concentration and ClCr. Pharmacokinetic parameters were calculated in 8 of these patients, and metformin accumulation was monitored in 10 patients before and after their exposure to CM. Linear response (r ≥ 0.998) was observed over the range of 5-2000 ng/mL of metformin, with the lower limit of quantification of 2.3 ng/mL. The intraday and interday precision (relative standard deviation) values were &amp;amp;amp;lt;13%, and the accuracy (relative error) was &amp;amp;amp;lt;-10% for metformin concentrations. The assay was sensitive to follow the pharmacokinetics of metformin in humans during a dosing interval after an oral dose at steady state. Metformin pharmacokinetic parameters were estimated in 8 patients exposed to CM. The mean C(max) of 1.9 ± 0.6 mg/L was attained at 4.1 ± 1.9 hours. There was no evidence of any drug accumulation or altered elimination due to the exposure to CM in the current population. ClCr showed no significant difference (P &amp;amp;amp;gt; 0.05) before (92.8 ± 11.3 mL/min) and after 48 hours (90.5 ± 10.5 mL/min) of exposure to CM. Our data suggest that the recommendation to withhold metformin in diabetic patients during CM exposure could be revised to withholding the drug only in patients with moderate to severe renal dysfunction.