Hossein Amini | Sistan and Baluchestan (original) (raw)
Papers by Hossein Amini
Pharmacology Biochemistry and Behavior, 2002
The effects of formalin-induced tonic pain (FITP) on testosterone (T) concentrations in the centr... more The effects of formalin-induced tonic pain (FITP) on testosterone (T) concentrations in the central nervous system (CNS) and serum were investigated in rats. T was nearly eliminated from the brain and spinal cord 1.5 and 24 h after a single subcutaneous injection (100 ml/rat, sc) of 5% formalin and its levels were similar to that seen following castration. In serum, T concentrations were decreased significantly 1.5 h following formalin injection, but after 24 h, the serum level of T was within normal range. T concentrations in the brain, spinal cord, and serum were not modified 20 min after formalin injection. Pretreatment of rats with finasteride, a 5a-reductase (5a-R) inhibitor (5 mg/kg, sc) blocked T elimination from the brain and spinal cord by FITP, but it failed to prevent decrease in serum T. However, 3 h after administration of exogenous T (5 mg/kg, sc), FITP did not cause a significant decrease in T levels in the CNS and serum. These results suggest that FITP eliminates endogenous T in the brain and spinal cord by increasing 5a-R activity in the CNS. D
Clinical Drug Investigation, 2008
aciclovir tablets, Rouz-Aciclovir (test) and Zovirax ® (reference), in 12 healthy volunteers.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2004
A simple and sensitive high-performance liquid chromatographic (HPLC) method with spectrophotomet... more A simple and sensitive high-performance liquid chromatographic (HPLC) method with spectrophotometric detection was developed for the determination of moclobemide in human plasma. Plasma samples were extracted under basic conditions with dichloromethane followed by back-extraction into diluted phosphoric acid. Isocratic separation was employed on an ODS column (250 mm x 4.6 mm, 5 microm) at room temperature. The mobile phase consisted of 5 mM NaH2PO4-acetonitrile-triethylamine (1000:350:10 (v/v/v), pH 3.4). Analyses were run at a flow-rate of 1.0 ml/min and ultraviolet (UV) detection was carried out at 240 nm. The method was specific and sensitive with a quantification limit of 15.6 ng/ml and a detection limit of 5 ng/ml at a signal-to-noise ratio of 3:1. The mean absolute recovery was about 98.2%, while the intra- and inter-day coefficient of variation and percent error values of the assay method were all at acceptable levels. Linearity was assessed in the range of 15.6-2000 ng/ml in plasma with a correlation coefficient of greater than 0.999. This method has been used to analyze several hundred human plasma samples for bioavailibility studies.
Journal of Chromatography B: Biomedical Sciences and Applications, 2001
A simple high-performance liquid chromatographic procedure was developed for the determination of... more A simple high-performance liquid chromatographic procedure was developed for the determination of ranitidine in human plasma. The method entailed direct injection of the plasma samples after deproteination using perchloric acid. The chromatographic separation was accomplished with an isocratic elution using mobile phase consisting of 21 mM disodium hydrogen phosphate-triethylamine-acetonitrile (1000:60:150, v / v), pH 3.5. Analyses were run at a flow-rate of 1.3 ml / min using a mbondapak C column and ultraviolet detection at a wavelength of 320 nm. The method was specific and sensitive, 18 with a quantification limit of approximately 20 ng / ml and a detection limit of 5 ng / ml at a signal-to-noise ratio of 3:1. The mean absolute recovery was about 96%, while the within-and between-day coefficient of variation and percent error values of the assay method were all less than 8%. The linearity was assessed in the range of 20-1000 ng / ml plasma, with a correlation coefficient of greater than 0.999. This method has been used to analyze several hundred human plasma samples for bioavailability studies.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2006
We developed and validated a semi-automated LC/LC-MS/MS assay for the quantification of imatinib ... more We developed and validated a semi-automated LC/LC-MS/MS assay for the quantification of imatinib in human whole blood and leukemia cells. After protein precipitation, samples were injected into the HPLC system and trapped onto the enrichment column (flow 5 mL/min); extracts were back-flushed onto the analytical column. Ion transitions [M + H] + of imatinib (m/z = 494.3 → 394.3) and its internal standard trazodone (372.5 → 176.3) were monitored. The range of reliable response was 0.03-75 ng/mL. The inter-day precisions were: 8.4% (0.03 ng/mL), 7.2% (0.1 ng/mL), 6.5% (1 ng/mL), 8.2% (10 ng/mL) and 4.3% (75 ng/mL) with no interference from ion suppression. Autosampler stability was 24 hs and samples were stable over three freeze-thaw cycles. This semi-automated method is simple with only one manual step, uses a commercially available internal standard, and has proven to be robust in larger studies.
International Journal of Developmental Neuroscience, 2005
In the present study, the effects of acute and chronic morphine exposure on testosterone concentr... more In the present study, the effects of acute and chronic morphine exposure on testosterone concentrations in the central nervous system (CNS) and serum were investigated in rats. Acute morphine administration (5 mg/kg, sc) reduced significantly testosterone levels in serum and spinal cord but not in the brain. Following chronic morphine administration (orally for 21 days), the brain testosterone was also significantly reduced as well as serum and spinal cord. Since, the decrease in testosterone levels following morphine exposure was more obvious in the CNS than serum, we suggested that it cannot be caused by only a direct decline in testosterone levels in periphery, and an increased local metabolism of testosterone in the CNS might be attributed in these effects. This hypothesis was supported with the findings that pretreatment with finasteride, a 5alpha-reductase inhibitor (5 mg/kg, sc) blocked testosterone elimination from the CNS following morphine exposure. Moreover, the serum concentration of 5alpha-reduced metabolites of testosterone, dihydrotestosterone and 3alpha-diol glucuronide was increased significantly following chronic morphine exposure, but not after co-treatment with finasteride. These results suggest that morphine exposure increase the CNS activity of 5alpha-reductase, which is an important metabolizing enzyme for testosterone.
Clinical Drug Investigation, 2004
Chemical structures of (a) losartan and (b) its active metabolite EXP3174.
Pharmacology Biochemistry and Behavior, 2011
Little is known about the role of steroidogenic enzymes in pain modulation. This study examined t... more Little is known about the role of steroidogenic enzymes in pain modulation. This study examined the effects of 5α-reductase and aromatase inhibition on formalin-induced tonic pain (FITP) in adult female rats. The animals received subcutaneous injection (5 mg/kg) of finasteride (an inhibitor of 5α-reductase) and letrozole (an inhibitor of aromatase), either separately or in combination, 15 min before formalin injection at a low (0.25%) and high (2.5%) concentration. Pretreatment with inhibitors increased FITP evoked by injection of 0.25% formalin, but they were not effective on 2.5% formalin pain. The enhancing effects of finasteride and letrozole on FITP induced by 2.5% formalin was demonstrated by inhibitory actions of these drugs on morphine (7 and 10 mg/kg, intraperitoneal) induced antinociception. The nervous system could be considered as the main target of the enzymes inhibition, since the pronociceptive effect was also observed after administration of inhibitors to ovariectomized rats. Altogether, these findings suggest that the biological activity of the enzymes 5α-reductase and aromatase modulates FITP and may help to develop effective therapeutic strategies to counteract pain.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2005
A rapid, selective and sensitive high-performance liquid chromatographic method with spectrophoto... more A rapid, selective and sensitive high-performance liquid chromatographic method with spectrophotometric detection was developed for the determination of clarithromycin in human plasma. Liquid-liquid extraction of clarithromycin and norverapamil (as internal standard) from plasma samples was performed with n-hexane/1-butanol (98:2, v/v) in alkaline condition followed by back-extraction into diluted acetic acid. Chromatography was carried out using a CN column (250 mm x 4.6 mm, 5 microm) under isocratic elution with acetonitrile-50 mM aqueous sodium dihydrogen phosphate (32:68, v/v), pH 4.5. Detection was made at 205 nm and analyses were run at a flow-rate of 1.0 ml/min at 40 degrees C. The analysis time was less than 11 min. The method was specific and sensitive with a quantification limit of 31.25 ng/ml and a detection limit of 10 ng/ml in plasma. The mean absolute recovery of clarithromycin from plasma was 95.9%, while the intra- and inter-day coefficient of variation and percent error values of the assay method were all less than 9.5%. Linearity was assessed in the range of 31.25-2000 ng/ml in plasma with a correlation coefficient of greater than 0.999. The method was used to analyze several hundred human plasma samples for bioavailability studies.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2004
A simple and rapid high-performance liquid chromatographic method with fluorescence detection was... more A simple and rapid high-performance liquid chromatographic method with fluorescence detection was developed for the determination of loratadine in small volume plasma samples. Liquid-liquid extraction of loratadine and diazepam (as internal standard) from plasma samples was performed with n-butyl alcohol/n-hexane (2:98, v/v) in alkaline condition followed by back-extraction into diluted perchloric acid. Chromatography was carried out using a C8 column (250 x 4.6 mm, 5 microm) under isocratic elution with acetonitrile-20 mM sodium dihydrogen phosphate-triethylamine (43:57:0.02, v/v), pH 2.4. Analyses were run at a flow-rate of 1.0 ml/min at room temperature. The method was specific and sensitive with a quantitation limit of 0.62 ng/ml and a detection limit of 0.2 ng/ml at a signal-to-noise ratio of 3:1. The mean absolute recovery of loratadine from plasma was 84%, while the intra-and inter-day coefficient of variation and percent error values of the assay method were all less than 9.7%. Linearity was assessed in the range of 0.62-20 ng/ml in plasma with a correlation coefficient of greater than 0.999. The method has been used to analyze several hundred human plasma samples for bioavailability studies.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2005
A simple, selective, sensitive and precise high-performance liquid chromatographic plasma assay f... more A simple, selective, sensitive and precise high-performance liquid chromatographic plasma assay for the hypoglycemic agent metformin is described. Acidified samples of plasma were deproteinated with acetonitrile, washed with dichloromethane and the resulting supernatant injected. Chromatography was performed at 408C by pumping a mobile phase of acetonitrile (250 ml) in pH 7, 0.03 M diammonium hydrogen phosphate buffer (750 ml) at a flow-rate of 1 ml / min through a silica column. Metformin and the internal standard (atenolol) were detected at 240 nm and were eluted 7.8 and 6.8 min, respectively, after injection. No endogenous substances were found to interfere. Calibration curves were linear (r.0.999) from 10 to 2000 ng / ml. The absolute recovery of both metformin and atenolol was greater than 76%. The detection limit and limit of quantitation were 2.5 and 10 ng / ml, respectively. The intra-and inter-day precision (C. V.) was 12%, or less, and the accuracy was within 6.2% of the nominal concentration. This method is suitable for clinical investigation and monitoring metformin concentration.
Journal of Pharmaceutical and Biomedical Analysis, 2007
A simple and reproducible high-performance liquid chromatographic method was developed for simult... more A simple and reproducible high-performance liquid chromatographic method was developed for simultaneous determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in human plasma. The method entailed injection of the samples after deproteination with perchloric acid and subsequent neutralizing. Primidone was used as internal standard. Chromatography was performed on a C(18) column (250 mm x 4.6 mm, 5 microm) under isocratic elution with 50 mM aqueous sodium dihydrogen phosphate-acetonitrile-triethylamine (100:25:0.5, v/v), pH 5.9. Detection was made at 240 nm and analyses were run at a flow-rate of 1.5 ml/min at a temperature of 35 degrees C. The recovery was 83.4, 88.5 and 98.2% for TMP, SMX and internal standard, respectively. The precision of the method was 2.6-9.8% over the concentration range of 0.125-2 microg/ml for TMP and 0.39-50 microg/ml for SMX. The limit of quantification (LOQ) in plasma was 0.125 and 0.39 microg/ml for TMP and SMX, respectively. The method was used for a bioequivalence study.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2003
A simple and reproducible high-performance liquid chromatography (HPLC) method was developed for ... more A simple and reproducible high-performance liquid chromatography (HPLC) method was developed for determination of cyclosporine (CyA, also known as cyclosporin A) in human whole blood. The method entailed direct injection of the blood samples after deproteination using acetonitrile. Chromatography was carried out using an ODS column under isocratic elution with acetonitrile-5mM disodium hydrogen phosphate (75:25, v/v), pH 5.1 at 70 degrees C and a detector set at 210 nm. The mean absolute recovery of cyclosporine from blood was 97%, and the linearity was assessed in the range of 100-3000 ng/ml blood, with a correlation coefficient of greater than 0.999. The limit of quantification and detection of the present method were 100 and 50 ng/ml, respectively. This method has been used to analyze several hundred human blood samples for bioavailability studies.
Pharmacology Biochemistry and Behavior, 2002
The effects of formalin-induced tonic pain (FITP) on testosterone (T) concentrations in the centr... more The effects of formalin-induced tonic pain (FITP) on testosterone (T) concentrations in the central nervous system (CNS) and serum were investigated in rats. T was nearly eliminated from the brain and spinal cord 1.5 and 24 h after a single subcutaneous injection (100 ml/rat, sc) of 5% formalin and its levels were similar to that seen following castration. In serum, T concentrations were decreased significantly 1.5 h following formalin injection, but after 24 h, the serum level of T was within normal range. T concentrations in the brain, spinal cord, and serum were not modified 20 min after formalin injection. Pretreatment of rats with finasteride, a 5a-reductase (5a-R) inhibitor (5 mg/kg, sc) blocked T elimination from the brain and spinal cord by FITP, but it failed to prevent decrease in serum T. However, 3 h after administration of exogenous T (5 mg/kg, sc), FITP did not cause a significant decrease in T levels in the CNS and serum. These results suggest that FITP eliminates endogenous T in the brain and spinal cord by increasing 5a-R activity in the CNS. D
Clinical Drug Investigation, 2008
aciclovir tablets, Rouz-Aciclovir (test) and Zovirax ® (reference), in 12 healthy volunteers.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2004
A simple and sensitive high-performance liquid chromatographic (HPLC) method with spectrophotomet... more A simple and sensitive high-performance liquid chromatographic (HPLC) method with spectrophotometric detection was developed for the determination of moclobemide in human plasma. Plasma samples were extracted under basic conditions with dichloromethane followed by back-extraction into diluted phosphoric acid. Isocratic separation was employed on an ODS column (250 mm x 4.6 mm, 5 microm) at room temperature. The mobile phase consisted of 5 mM NaH2PO4-acetonitrile-triethylamine (1000:350:10 (v/v/v), pH 3.4). Analyses were run at a flow-rate of 1.0 ml/min and ultraviolet (UV) detection was carried out at 240 nm. The method was specific and sensitive with a quantification limit of 15.6 ng/ml and a detection limit of 5 ng/ml at a signal-to-noise ratio of 3:1. The mean absolute recovery was about 98.2%, while the intra- and inter-day coefficient of variation and percent error values of the assay method were all at acceptable levels. Linearity was assessed in the range of 15.6-2000 ng/ml in plasma with a correlation coefficient of greater than 0.999. This method has been used to analyze several hundred human plasma samples for bioavailibility studies.
Journal of Chromatography B: Biomedical Sciences and Applications, 2001
A simple high-performance liquid chromatographic procedure was developed for the determination of... more A simple high-performance liquid chromatographic procedure was developed for the determination of ranitidine in human plasma. The method entailed direct injection of the plasma samples after deproteination using perchloric acid. The chromatographic separation was accomplished with an isocratic elution using mobile phase consisting of 21 mM disodium hydrogen phosphate-triethylamine-acetonitrile (1000:60:150, v / v), pH 3.5. Analyses were run at a flow-rate of 1.3 ml / min using a mbondapak C column and ultraviolet detection at a wavelength of 320 nm. The method was specific and sensitive, 18 with a quantification limit of approximately 20 ng / ml and a detection limit of 5 ng / ml at a signal-to-noise ratio of 3:1. The mean absolute recovery was about 96%, while the within-and between-day coefficient of variation and percent error values of the assay method were all less than 8%. The linearity was assessed in the range of 20-1000 ng / ml plasma, with a correlation coefficient of greater than 0.999. This method has been used to analyze several hundred human plasma samples for bioavailability studies.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2006
We developed and validated a semi-automated LC/LC-MS/MS assay for the quantification of imatinib ... more We developed and validated a semi-automated LC/LC-MS/MS assay for the quantification of imatinib in human whole blood and leukemia cells. After protein precipitation, samples were injected into the HPLC system and trapped onto the enrichment column (flow 5 mL/min); extracts were back-flushed onto the analytical column. Ion transitions [M + H] + of imatinib (m/z = 494.3 → 394.3) and its internal standard trazodone (372.5 → 176.3) were monitored. The range of reliable response was 0.03-75 ng/mL. The inter-day precisions were: 8.4% (0.03 ng/mL), 7.2% (0.1 ng/mL), 6.5% (1 ng/mL), 8.2% (10 ng/mL) and 4.3% (75 ng/mL) with no interference from ion suppression. Autosampler stability was 24 hs and samples were stable over three freeze-thaw cycles. This semi-automated method is simple with only one manual step, uses a commercially available internal standard, and has proven to be robust in larger studies.
International Journal of Developmental Neuroscience, 2005
In the present study, the effects of acute and chronic morphine exposure on testosterone concentr... more In the present study, the effects of acute and chronic morphine exposure on testosterone concentrations in the central nervous system (CNS) and serum were investigated in rats. Acute morphine administration (5 mg/kg, sc) reduced significantly testosterone levels in serum and spinal cord but not in the brain. Following chronic morphine administration (orally for 21 days), the brain testosterone was also significantly reduced as well as serum and spinal cord. Since, the decrease in testosterone levels following morphine exposure was more obvious in the CNS than serum, we suggested that it cannot be caused by only a direct decline in testosterone levels in periphery, and an increased local metabolism of testosterone in the CNS might be attributed in these effects. This hypothesis was supported with the findings that pretreatment with finasteride, a 5alpha-reductase inhibitor (5 mg/kg, sc) blocked testosterone elimination from the CNS following morphine exposure. Moreover, the serum concentration of 5alpha-reduced metabolites of testosterone, dihydrotestosterone and 3alpha-diol glucuronide was increased significantly following chronic morphine exposure, but not after co-treatment with finasteride. These results suggest that morphine exposure increase the CNS activity of 5alpha-reductase, which is an important metabolizing enzyme for testosterone.
Clinical Drug Investigation, 2004
Chemical structures of (a) losartan and (b) its active metabolite EXP3174.
Pharmacology Biochemistry and Behavior, 2011
Little is known about the role of steroidogenic enzymes in pain modulation. This study examined t... more Little is known about the role of steroidogenic enzymes in pain modulation. This study examined the effects of 5α-reductase and aromatase inhibition on formalin-induced tonic pain (FITP) in adult female rats. The animals received subcutaneous injection (5 mg/kg) of finasteride (an inhibitor of 5α-reductase) and letrozole (an inhibitor of aromatase), either separately or in combination, 15 min before formalin injection at a low (0.25%) and high (2.5%) concentration. Pretreatment with inhibitors increased FITP evoked by injection of 0.25% formalin, but they were not effective on 2.5% formalin pain. The enhancing effects of finasteride and letrozole on FITP induced by 2.5% formalin was demonstrated by inhibitory actions of these drugs on morphine (7 and 10 mg/kg, intraperitoneal) induced antinociception. The nervous system could be considered as the main target of the enzymes inhibition, since the pronociceptive effect was also observed after administration of inhibitors to ovariectomized rats. Altogether, these findings suggest that the biological activity of the enzymes 5α-reductase and aromatase modulates FITP and may help to develop effective therapeutic strategies to counteract pain.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2005
A rapid, selective and sensitive high-performance liquid chromatographic method with spectrophoto... more A rapid, selective and sensitive high-performance liquid chromatographic method with spectrophotometric detection was developed for the determination of clarithromycin in human plasma. Liquid-liquid extraction of clarithromycin and norverapamil (as internal standard) from plasma samples was performed with n-hexane/1-butanol (98:2, v/v) in alkaline condition followed by back-extraction into diluted acetic acid. Chromatography was carried out using a CN column (250 mm x 4.6 mm, 5 microm) under isocratic elution with acetonitrile-50 mM aqueous sodium dihydrogen phosphate (32:68, v/v), pH 4.5. Detection was made at 205 nm and analyses were run at a flow-rate of 1.0 ml/min at 40 degrees C. The analysis time was less than 11 min. The method was specific and sensitive with a quantification limit of 31.25 ng/ml and a detection limit of 10 ng/ml in plasma. The mean absolute recovery of clarithromycin from plasma was 95.9%, while the intra- and inter-day coefficient of variation and percent error values of the assay method were all less than 9.5%. Linearity was assessed in the range of 31.25-2000 ng/ml in plasma with a correlation coefficient of greater than 0.999. The method was used to analyze several hundred human plasma samples for bioavailability studies.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2004
A simple and rapid high-performance liquid chromatographic method with fluorescence detection was... more A simple and rapid high-performance liquid chromatographic method with fluorescence detection was developed for the determination of loratadine in small volume plasma samples. Liquid-liquid extraction of loratadine and diazepam (as internal standard) from plasma samples was performed with n-butyl alcohol/n-hexane (2:98, v/v) in alkaline condition followed by back-extraction into diluted perchloric acid. Chromatography was carried out using a C8 column (250 x 4.6 mm, 5 microm) under isocratic elution with acetonitrile-20 mM sodium dihydrogen phosphate-triethylamine (43:57:0.02, v/v), pH 2.4. Analyses were run at a flow-rate of 1.0 ml/min at room temperature. The method was specific and sensitive with a quantitation limit of 0.62 ng/ml and a detection limit of 0.2 ng/ml at a signal-to-noise ratio of 3:1. The mean absolute recovery of loratadine from plasma was 84%, while the intra-and inter-day coefficient of variation and percent error values of the assay method were all less than 9.7%. Linearity was assessed in the range of 0.62-20 ng/ml in plasma with a correlation coefficient of greater than 0.999. The method has been used to analyze several hundred human plasma samples for bioavailability studies.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2005
A simple, selective, sensitive and precise high-performance liquid chromatographic plasma assay f... more A simple, selective, sensitive and precise high-performance liquid chromatographic plasma assay for the hypoglycemic agent metformin is described. Acidified samples of plasma were deproteinated with acetonitrile, washed with dichloromethane and the resulting supernatant injected. Chromatography was performed at 408C by pumping a mobile phase of acetonitrile (250 ml) in pH 7, 0.03 M diammonium hydrogen phosphate buffer (750 ml) at a flow-rate of 1 ml / min through a silica column. Metformin and the internal standard (atenolol) were detected at 240 nm and were eluted 7.8 and 6.8 min, respectively, after injection. No endogenous substances were found to interfere. Calibration curves were linear (r.0.999) from 10 to 2000 ng / ml. The absolute recovery of both metformin and atenolol was greater than 76%. The detection limit and limit of quantitation were 2.5 and 10 ng / ml, respectively. The intra-and inter-day precision (C. V.) was 12%, or less, and the accuracy was within 6.2% of the nominal concentration. This method is suitable for clinical investigation and monitoring metformin concentration.
Journal of Pharmaceutical and Biomedical Analysis, 2007
A simple and reproducible high-performance liquid chromatographic method was developed for simult... more A simple and reproducible high-performance liquid chromatographic method was developed for simultaneous determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in human plasma. The method entailed injection of the samples after deproteination with perchloric acid and subsequent neutralizing. Primidone was used as internal standard. Chromatography was performed on a C(18) column (250 mm x 4.6 mm, 5 microm) under isocratic elution with 50 mM aqueous sodium dihydrogen phosphate-acetonitrile-triethylamine (100:25:0.5, v/v), pH 5.9. Detection was made at 240 nm and analyses were run at a flow-rate of 1.5 ml/min at a temperature of 35 degrees C. The recovery was 83.4, 88.5 and 98.2% for TMP, SMX and internal standard, respectively. The precision of the method was 2.6-9.8% over the concentration range of 0.125-2 microg/ml for TMP and 0.39-50 microg/ml for SMX. The limit of quantification (LOQ) in plasma was 0.125 and 0.39 microg/ml for TMP and SMX, respectively. The method was used for a bioequivalence study.
Journal of Chromatography B-analytical Technologies in The Biomedical and Life Sciences, 2003
A simple and reproducible high-performance liquid chromatography (HPLC) method was developed for ... more A simple and reproducible high-performance liquid chromatography (HPLC) method was developed for determination of cyclosporine (CyA, also known as cyclosporin A) in human whole blood. The method entailed direct injection of the blood samples after deproteination using acetonitrile. Chromatography was carried out using an ODS column under isocratic elution with acetonitrile-5mM disodium hydrogen phosphate (75:25, v/v), pH 5.1 at 70 degrees C and a detector set at 210 nm. The mean absolute recovery of cyclosporine from blood was 97%, and the linearity was assessed in the range of 100-3000 ng/ml blood, with a correlation coefficient of greater than 0.999. The limit of quantification and detection of the present method were 100 and 50 ng/ml, respectively. This method has been used to analyze several hundred human blood samples for bioavailability studies.