Batch and flow-injection methods for the spectrophotometric determination of olanzapine

Integrated spectroscopic approaches for the facile one pot quantification of olanzapine in pharmaceutical formulation and spiked human plasma

In this work, the xanthene dye, erythrosine B, was employed as a probe for the determination of olanzapine using two fast and highly simple analytical approaches. The assay was based on the formation of a binary complex between the drug and erythrosine B in a slightly acidic aqueous buffered solution. In the first method, the absorbance of the formed product was monitored at 558 nm. The reaction stoichiometry was investigated, and the stability constant of the formed complex was estimated. The linear range of the method that obeyed Beer's law was in the concentration range of 0.6-8.0 µg/ml. The calculated detection and quantitation limits were 0.2 and 0.6 µg/mL. Upon adding the drug solution to erythrosine B, the native fluorescence of the dye was quenched and monitored at 550 nm after excitation at 528 nm. Thus, the fluorescence quenching was utilized as the quantitative signal in the spectrofluorimetric approach. The extent of quenching in the fluorescence intensity was rectilinear with the drug concentration in a range of 0.1-2.5 µg/ml with a detection limit of 0.032 µg/ml. Both approaches were analytically validated based on the guiding rules of the ICH with acceptable results, and were utilized efficiently in the analysis of olanzapine in commercial tablets containing the cited drug. In addition, owing to its high sensitivity and selectivity, the spectrofluorimetric method was applied for drug analysis in spiked human plasma with satisfactory % recoveries. Finally, the greenness of the methods was confirmed using eco-score scale and Analytical Green Evaluation metrics.

Spectrofluorimetric first derivative synchronous approach for determination of olanzapine and samidorphan used for treatment of schizophrenia in pharmaceutical formulations and human plasma

The combination of olanzapine and samidorphan has just been authorised for the treatment of schizophrenia. The current study created a very accurate, sensitive and selective spectroscopic technique based on the first derivative of synchronous fluorescence for determining olanzapine and samidorphan in their pharmaceutical prescriptions without prior separation. For the quantitative analysis of samidorphan and olanzapine, the adopted approach is focused on measuring the synchronised fluorescence intensity of the examined medicines at fixed wavelength range (Δλ) = 50 nm and the first derivative's peak magnitudes were observed at 300 and 350 nm, respectively. The effects of various factors on the synchronised fluorescence intensity of the referenced medications were researched and adjusted. Both medications' calibrating charts were shown to be linear throughout a range of concentrations of 0.1-1.1 µg mL-1. LOD for SAM and OLA were 0.02 and 0.01, respectively. In addition, LOQ was determined for SAM and OLA as follow, 0.07 and 0.06, respectively. The devised approach was effectively used to the quantitative measurement of the two medicines in Lybalvi® tablets with various samidorphan and olanzapine ratios, in addition to spiked human plasma. A variance ratio F-test and student t-test were needed to be able to compare the results to another published analytical technique and found no significant differences.

A Comprehensive Review on Importance and Quantitation of Atypical Antipsychotic Drugs and their Active Metabolites in Commercial Dosage Forms

Background:

Schizophrenia is a severe mental illness that affects more than twenty-one million people throughout the world. Schizophrenia also causes early death. Schizophrenia and other related psychotic ailments are controlled by the prescription of antipsychotic drugs, which act by blocking certain chemical receptors in the brain and thus relieves the symptoms of psychotic disorder. These drugs are present in the different dosage forms in the market and provided in a certain amount as per the need of the patients.

Objective:

Since such medications treat mental disorders, it is very important to have a perfect and accurate dose so that the risk factor is not affected by a higher or lower dose, which is not sufficient for the treatment. For accurate assay of these kinds of drugs, different analytical methods were developed ranging from older spectrophotometric techniques to latest hyphenated methods.

Results:

The current review highlights the role of different analytical techniques that were employed in the determination and identification of antipsychotic drugs and their metabolites. Techniques such as spectrophotometry, fluorimetry, liquid chromatography, liquid chromatography-mass spectrometry, gas chromatography, and gas chromatography-mass spectrometry employed in the method development of such antipsychotic drugs were reported in the review. Different metabolites, identified using the hyphenated techniques, were also mentioned in the review. The synthesis pathways of few of the metabolites were mentioned.

Conclusion:

The review summarizes the analyses of different antipsychotic drugs and their metabolites. A brief introduction of illnesses and their symptoms and possible medications were highlighted. Synthesis pathways of the associated metabolites were also mentioned.

Differential pulse stripping voltammetric determination of the antipsychotic medication olanzapine at a magnetic nano-composite with a core/shell structure

Fe₃O₄@Ag core/shell MNPs were used for modification of carbon paste electrode and the modified electrode was utilized for electrochemical determination of olanzapine.

Olanzapine: palliative medicine update

Olanzapine is an atypical antipsychotic agent of the thienobenzodiazepine class. Olanzapine blocks multiple neurotransmitter receptors, including dopaminergic (D(1), D(2), D(3), and D(4)), serotonergic (5-hydroxytryptamine 2A [5-HT(2A)], 5-HT(2C), 5-HT(3), and 5-HT(6)), adrenergic (α(1)), histaminic (H(1)), and muscarinic (M(1), M(2), M(3), and M(4)) receptors. Olanzapine has a high affinity for the 5HT(2A) receptor, which is up to 5 times greater than the dopamine receptor, resulting in less propensity to the development of extrapyramidal side effects. The affinity of olanzapine for multiple receptors has lead to the identification of olanzapine as an important agent in the treatment of delirium, nausea, and vomiting. Olanzapine has been demonstrated to have opioid-sparing properties. Olanzapine is principally metabolized by glucuronidation, with a smaller metabolic contribution from the cytochrome oxidase system. Adverse effects of olanzapine include somnolence, postural hypotension, constipation, dizziness, restlessness, and weight gain. The purpose of this article is to outline the pharmacodynamics, pharmacology, and evidence for the use of olanzapine in palliative care.

Determination of olanzapine by spectrophotometry using permanganate

Two new spectrophotometric methods using permanganate as the oxidimetric reagent for the determination of olanzapine (OLP) were developed and validated as per the current ICH guidelines. The methods involved the addition of known excess of permanganate to OLP in either acid or alkaline medium followed by the determination of unreacted permanganate at 550 nm (method A) or bluish-green color of manganate at 610 nm (method B). The decrease in absorbance in method A or increase in absorbance in method B as a function of concentration of OLP was measured and related to OLP concentration. Under optimized conditions, Beer's law was obeyed over the ranges 2.0 to 20 and 1.0 to 10 μg mL-1 in method A and method B, respectively. The calculated molar absorptivity values were 1.34 x 10(4) and 2.54 x 10(4) l mol-1cm-1 for method A and method B respectively, and the respective Sandell sensitivities were 0.0233 and 0.0123 μg cm-2. The LOD and LOQ for method A were calculated to be 0.37 and 1.13 μg mL-1and the corresponding values for method B were 0.16 and 0.48 μg mL-1. Intermediate precision, expressed as RSD was in the range 0.51 to 2.66 %, and accuracy, expressed as relative error ranged from 0.79 to 2.24 %. The proposed methods were successfully applied to the assay of OLP in commercial tablets with mean percentage recoveries of 102 ±1.59 % (method A) and 101 ±1.53 % (method B). The accuracy and reliability of the methods were further confirmed by performing recovery tests via standard addition procedure.

Spectrophotometric Determination of Olanzapine by Its Oxidation with N-Bromosuccinimide and Cerium(IV)sulfate

Three simple spectrophotometric methods have been described for the assay of olanzapine in its pure and pharmaceutical formulations. The direct method (A) is based on the drug oxidation with excess of N-bromosuccinimide in acidic medium and the two indirect methods (B and C) are based on the oxidation of the drug with excess of N-bromosuccinimide and cerium(IV)sulfate, followed by the reaction of the unconsumed oxidants with celestine blue. The calibration graphs were linear over the range 10 - 120 microg mL(-1) (method A), 0.5 - 6.0 microg mL(-1) (method B) and 0.6 - 3.0 microg mL(-1) (method C). After validation, the proposed methods were successfully applied to assay of olanzapine in its commercial tablets with mean percentage recoveries of 101.23 +/- 0.10, 96 +/- 0.10 and 94 +/- 0.04%. The mechanism of olanzapine oxidation with N-bromosuccinimide was also proposed.