Rapid microsample analysis of imipramine and desipramine by reversed-phase high-performance liquid chromatography with ultraviolet detection

Imipramine-induced c-Fos expression in the medial prefrontal cortex is decreased in the ACTH-treated rats

Previous studies have shown that the antidepressive-like effect of tricyclic antidepressants is blocked by repeated treatments with adrenocorticotropic hormone (ACTH). However, little is known about the neuroanatomy underlying the mechanism of the imipramine treatment-resistant depression model. In the present study, first experimental evidence showed no significant difference of the serum imipramine concentrations between the saline and ACTH-treated rats. In further study, imipramine produced significant increases in the c-Fos expression in the medial prefrontal cortex (mPFC), the dentate gyrus of the hippocampus (DGH), and the central nucleus of the amygdala (CeA), in rats repeatedly treated with saline. The imipramine-increased c-Fos immunoreactivity was suppressed in the mPFC of rats repeatedly treated with ACTH. However, there was no significant difference in c-Fos expression in the DGH and CeA between ACTH- and saline-treated rats. These results suggest that the mPFC is maybe involved in effects of the imipramine in the ACTH-treated rats.

Micellar electrokinetic chromatographic study of the separation of an aromatase inhibitor and a tryciclic antidepressant in the breast cancer treatment

Micellar electrokinetic chromatography (MEKC) was investigated for the simultaneous determination of letrozole, imipramine and their metabolites in human urine samples over a concentration range of therapeutic interest. Experimental parameters such as pH of the running electrolyte, sodium dodecylsulphate (SDS) concentration, borate concentration, voltage, etc were investigated. Under optimal conditions of 25 mM SDS, 15 mM borate buffer (pH 9.2), 15% 2-propanol, as background electrolyte; 28 kV and 40 degrees C, as voltage and cartridge temperature, respectively; resolution between the peaks was greater than 1.7. Before the determination, a solid phase extraction (SPE) procedure with a C(18) cartridge was optimized. Good linearity, accuracy, precision, robustness and ruggedness were achieved and detection limits of 12.5 ng/mL for letrozole and its metabolite and 37.5 ng/mL, were obtained for imipramine and their metabolites. Real determinations of these analytes in two patient urines were carried out. Sensitivity achieved in this method is sufficient to perform kinetic studies in humans.

Pharmacokinetic and pharmacodynamic studies of drug interaction following oral administration of imipramine and sodium alginate in rats

Recently, the use of health foods has increased due to growing interest in health maintenance. Previous in vitro studies have shown some drugs to be adsorbed by sodium alginate, a dietary fiber, and that such adsorption was marked with tricyclic antidepressants, such as imipramine. This study investigated the pharmacokinetic and pharmacological interactions between imipramine and sodium alginate in rats. The simultaneous administration of imipramine (30 mg/kg, oral (p.o.)) and sodium alginate (3.0%, p.o.) decreased the antidepressant-like activity of imipramine in a forced swimming test. In the rats administrated imipramine and 0.3%, 1.0%, or 3.0% sodium alginate, the geometric mean ratio of the Cmax values of imipramine was 72% [90% confidence intervals (CI) = 53-91%], 64% (90% CI = 47-80%), and 58% (90% CI = 50-67%), respectively. The geometric mean ratio of the AUC(0-6) values of imipramine were 68% (90% CI = 56-80%), 74% (90% CI = 60-89%), and 87% (90% CI = 73-102%), respectively. The decrease in Cmax and AUC(0-6) was judged to be significant with a 90% CI outside the 80-125% boundaries. In addition, the Tmax value of imipramine significantly increased (P < 0.05) by coadministration with 3.0% sodium alginate. These results suggested that simultaneous administration of sodium alginate decreased the serum concentration and pharmacological action of imipramine, through a delay in its absorption. Although the clinical relevance of these findings is unclear, it is important to pay considerable attention to the interactions between imipramine and sodium alginate.

Sensitive quantification of chosen drugs by reversed-phase chromatography with electrochemical detection at a glassy carbon electrode

Reversed-phase-high-performance liquid chromatographic method with electrochemical detection has proven to be a highly sensitive and selective method for determination of trace components in complex biological samples, and the electrochemical detector becomes an important alternative tool to ultraviolet and fluorescence detectors. A rapid and sensitive method for the accurate determination of metoclopramide, hydrochlorothiazide, imipramine and diclofenac in serum or plasma samples is described. The method is based on liquid-liquid extraction. The compounds were separated on C-18 column as stationary phase with a different binary mixture as mobile phase. Proposed method was validated with respect to specificity, linearity range, limit of detection and quantitation, precision, accuracy and successfully applied in a pharmacokinetic studies.

Determination of chlorprothixene and amitryptyline hydrochlorides by UV-derivative spectrophotometry and UV-solid-phase spectrophotometry

Two methods for spectrophotometric determination of chlorprothixene and amitryptyline hydrochlorides were proposed. One of them is based on spectral analysis of their derivative spectra. The measurement of the value at 316.0 nm of first derivative was used for construction of calibration graph for chlorprothixene. The Beer law was obeyed in the concentration range 0.5-50.0 microg ml(-1). The amplitude of the second derivative at 261.4 nm was used for determination of amitryptyline in the range 0.5-75.0 microg ml(-1). The second proposed method is utilized the use of solid sorbent for simultaneous preconcentration and assay of studied compounds. For this purpose the filtration gel Sephadex G100 was applied. The elaborated solid-phase spectrophotometric method was used for determination of chlorprothixene at 268.0 nm in the range 2.5-75.0 microg ml(-1) and amitryptyline at 238.0 nm in the concentration range 10.0-75.0 microg ml(-1).

Therapeutic monitoring of imipramine and desipramine by micellar liquid chromatography with direct injection and electrochemical detection

A micellar liquid chromatographic (MLC) procedure was developed for the clinical monitoring of imipramine and its active metabolite, desipramine. The determination of these highly hydrophobic substances was carried out after direct injection of the serum samples using a mobile phase composed of 0.15 m SDS--6% (v/v) pentanol buffered at pH 7, pumped at 1.5 mL/min into a C(18) column (250 x 4.6 mm), and electrochemical detection at 650 mV. Using this MLC method, calibration was linear (r > 0.995) and the limits of detection (ng/mL) were 0.34 and 0.24 for imipramine and desipramine, respectively. Repeatabilities and intermediate precision were tested at three different concentrations in the calibration range and a CV (%) below 2.2 was obtained. In this MLC procedure, the serum is determined without treatment, thus allowing repeated serial injections without changes in retention factors, and reducing the time and consumables required to carry out the pretreatment process. The assay method can be applied to the routine determination of serum imipramine and its metabolite in therapeutic drug monitoring.

The use of the new SPE methods for isolation of some tricyclic antidepressant drugs from human serum

Solid-phase extraction (SPE) methods were applied to isolation of amitriptyline (AMI), imipramine (IMI) and chlorprothixene (CPX) from blood human serum. SPE was carried out using the octadecyl (C(18)) column for isolation of AMI and cyclohexyl (CH) columns in the case of IMI and CPX. The spiked serum samples were used to examine the recoveries of these drugs from C(18) and CH sorbent materials. The volume of serum sample was 500 microl. The recoveries of SPE method using CH cartridge were 100.3+/-1.63% (n=7), 99.7+/-2.3% (n=9) for IMI and CPX, respectively. The recovery of AMI from C(18) cartridge was 99.5+/-1.5% (n=8). Finally, after SPE sample clean-up step the antidepressant drugs were assayed by the own extractive-spectrophotometric methods.

Studies and analytical application of reaction of imipramine with chrome azurol S

Chrome azurol S (CAS) was tested as a spectrophotometric reagent for the determination of imipramine (IMP). It reacts in aqueous media with IMP forming pink-red, sparingly soluble in water ion association compound. This compound was quantitatively extracted with chloroform and the absorbance of organic phase was measured at 510 nm. The extraction conditions were studied using a batch method. On the basis of the results obtained with batch method, three-line flow-injection system was constructed. Batch and flow-injection methods were successfully applied for the determination of IMP in pharmaceutical preparation.

Simultaneous LC determination of some antidepressants combined with neuroleptics

A reversed-phase HPLC method with UV detection at 252 nm is presented for the simultaneous determination of some tricyclic antidepressants (amitriptyline, imipramine) and neuroleptics (chlorprothixene, thioridazine) in their quaternary mixtures. Sample analysis was performed on a bonded reversed phase C-18, 5 microm, 250 x 4.6 mm ID (Lichrospher 100RP-18) column using acetonitrile and 0.01 M aqueous solution of triethylamine (1:1) as the mobile phase at 0.9 ml/min. The pH was adjusted to 2.7 with concentrated phosphoric acid. The retention time was for imipramine, amitriptyline, chlorprothixene, and thioridazine 5.8, 6.5, 8.3, 10.8 min, respectively. The linearity was obeyed up to 15 ppm for imipramine and amitriptyline, 12 ppm for chlorprothixene and 10 ppm for thioridazine. The presented method also allows the determination of the mentioned drugs individually in their pharmaceutical preparations.

Spectrophotometric studies and application of imipramine-eriochrome cyanine R system for determination of imipramine in pharmaceuticals

Eriochrome cyanine R (ECR) has been tested as reagent for the determination of imipramine. It reacts in neutral medium with imipramine forming reddish compound, which can be quantitatively extracted into n-butanol. This property has been successfully used for the extractive-spectrophotometric determination of imipramine. Beer's law is obeyed in concentration range of 10-80 microg ml(-1) of imipramine. The method was applied to the determination of imipramine in its pharmaceutical.

Kinetic interaction between fluoxetine and imipramine as a function of elevated serum alpha-1-acid glycoprotein levels

The effect of elevated serum alpha-1-acid glycoprotein (AAG) levels on the pharmacokinetic interaction between imipramine and fluoxetine has been examined by utilizing a novel strain of transgenic mice which express serum AAG levels several times greater than normal. Before fluoxetine treatment, serum imipramine levels were approximately three times greater in transgenic mice than in control mice. Despite higher serum imipramine levels in transgenic mice, brain drug levels were lower than those found in control mice. Fluoxetine pre-treatment (20 mg kg(-1) for 5 days) resulted in an increase in serum imipramine levels in both groups of mice and the extent of the increase was greater in transgenic mice than in control mice (4.5-fold increase compared with 3.1-fold). Similarly, fluoxetine pre-treatment resulted in an increase in brain levels of imipramine in both groups of mice and the extent of the increase was greater in transgenic mice than in control mice (3.0-fold increase compared with 2.0-fold). Similar trends were observed for levels of desipramine in the serum and brain. Serum imipramine and desipramine levels did not correlate with their respective brain levels in the presence of elevated serum AAG levels before and after pre-treatment. These findings indicate that the extent of increases in imipramine and desipramine serum and brain levels are greater during elevated serum AAG states than during normal AAG states when imipramine is co-administered with fluoxetine.

Sensitive microanalysis of imipramine and desipramine in single rat thyroids by gas chromatography-mass spectrometry

A new sensitive method for the quantitative determination of imipramine and desipramine in single rat thyroids using gas chromatography-mass spectrometry with selected ion monitoring, after enzymatic hydrolysis and liquid-liquid extraction has been developed. The technique was deemed suitable for microanalysis of single rat thyroids and for other solid tissues, using smaller sample sizes than usually required for traditional determination methods. The quantification was linear from 10 to 200 nmol/l (i.e., from 0.25 to 5 microg/g) for imipramine and from 100 nmol/l to 2000 nmol/l (i.e., from 2.4 to 47 microg/g) for desipramine, and the limits of detection (less than 25 ng/g tissue for both compounds) were better than those previously reported. Recoveries, repeatability and reproducibility of this technique were satisfactory. It has been successfully applied in a preliminary study of the concentration-time profiles of imipramine and desipramine in the thyroid of rats treated with either of these drugs.