Simultaneous Determination of Olanzapine and Fluoxetine by HPLC

Ecofriendly and smart spectrophotometric approaches for synchronized analysis of two antipsychotic drugs, fluoxetine and olanzapine: application to combined tablet dosages with assessment of method greenness

The present study was dedicated for solving the challenge of the overlapped spectra of olanzapine (OLZ) and fluoxetine (FLX) for their concurrent, accurate and precise determination without prior physical separation. The developed methods had to venture away from those that depend on chromatography, because of their negative effects on the environment due to using hazardous organic solvents as well as their high cost. The suggested methods were based on spectrophotometry combined with simple mathematical treatments of the spectra. These approaches are simple, rapid, inexpensive and reliable options for the effective assay of FLX and OLZ in pharmaceutical dosage forms. Ratio subtraction method was devoted for estimation of both drugs, while dual wavelength method and absorptivity factor method could be utilized in the estimation of FLX and OLZ, respectively. All the suggested methods were efficiently applied for the determination of the studied drugs in laboratory prepared mixtures and their pharmaceutical formulations. The environmental safety of the involved procedures was assessed by applying the Eco Score scale and complex modified GAPI methods. The methods were proved to be highly safe since no large volume of solvents were used, and no derivatizing reagent or drastic experimental conditions were involved. In addition, the procedures consume little energy and produce a small amount of waste. In conclusion, for FLX determination, the use of dual wavelength method is preferable because it needs very low mathematical treatment than the ratio subtraction method. However, for OLZ, the ratio subtraction method has higher sensitivity than absorptivity factor method although the latter is simpler.

Spectrophotometric determination of olanzapine, fluoxetine HCL and its impurity using univariate and chemometrics methods reinforced by latin hypercube sampling: Validation and eco-friendliness assessments

Novel univariate and chemometrics-aided UV spectrophotometric methods were tailored to undergo the fundamentals of green and white analytical chemistry for the simultaneous estimation of a ternary mixture of olanzapine (OLA), fluoxetine HCL (FLU), and its toxic impurity 4-(Trifluoromethyl) phenol (FMP) without any prior separation. The dual-wavelength ratio spectrum univariate method was used to determine OLA and FLU in the presence of FMP in the range of (4-20) and (5-50) μg/ml, respectively. In compliance with the International Conference on Harmonization (ICH) standards, the technique was validated and established Remarkable accuracy (98-102%) and precision (< 2%) with limits of quantification (LOQs) of 0.432 and 2.002 μg/ml, respectively. Partial least squares (PLS) and artificial neural networks (ANNs) are chemometric methodologies that have advantages over the univariate method and use significant innovations employing Latin hypercube sampling (LHS), allowing the generation of a reliable validation set to guarantee the effectiveness and sustainability of these models. The concentration ranges used were (2-20), (2-20), and (5-50) μg/ml; for PLS, the LOQs were 0.602, 0.508, and 1.429 μg/ml, and the root mean square errors of prediction (RMSEPs) were 0.087, 0.048, and 0.159 for OLA, FMP, and FLU, respectively; and for ANNs, the LOQs were 0.551, 0.465, and 0.965 μg/ml, with RMSEPs of 0.056, 0.047, and 0.087 for OLA, FMP, and FLU, respectively. The developed methods yield a greener National Environmental Methods Index (NEMI) with an eco-scale assessment (ESA) score of 90 and a complementary Green Analytical Procedure Index (complex GAPI) in quadrants with an analytical greenness metric (AGREE) score of 0.8. The Red‒Green-Blue 12 algorithm (RGB 12) scored 88.9, outperforming on reported methods and demonstrating widespread practical and environmental approval. Statistical analysis revealed no noteworthy differences (P > 0.05) among the proposed and published techniques. Both pure powders and pharmaceutical capsules were analyzed via these methods.

Cocrystals, Salts, and Salt-Solvates of olanzapine; selection of coformers and improved solubility

Pharmaceutical cocrystals and salts are extensively researched in recent years due to their ability to tune the physicochemical properties of active pharmaceutical ingredients (APIs). A model API, olanzapine, an atypical antipsychotic drug classified as Biopharmaceutical Classification System class II, is used in this study. Cocrystals and salts of olanzapine are discovered using solvent drop grinding and ball milling. Appropriate coformers were selected based on a combination of hydrogen-bond propensity (HBP) and hydrogen-bond coordination (HBC) calculations. Eight new multicomponent phases of olanzapine, including one cocrystal hydrate with phenol; four anhydrous salts with salicylic acid, terephthalic acid, anthranilic acid, 3-hydroxybenzoic acid, and 2-aminoterephthalic acid; one salt dihydrate with terephthalic acid; and one salt solvate with 3-hydroxybenzoic acid and acetonitrile, have been discovered and characterized by PXRD and DSC. One reported cocrystal (olanzapine-resorcinol) has also been considered for the dissolution test. All these newly formed solid phases followed the "ΔpK_a rule of 3". The crystal structures of cocrystal/salts were determined by single-crystal X-ray (sc-XRD) diffraction. With the collected single-crystal data, the crystal packings were found to be primarily stabilized via strong hydrogen bonds between carboxyl, phenolic hydroxyl of co-formers/salt-formers with the piperazine and diazepine nitrogen of olanzapine, which confirmed the predicted result from the HBP and HBC calculations. HPLC coupled with UV-vis detector was used in the solubility and dissolution test instead of UV-vis spectroscopy, to avoid the peak overlap between olanzapine and co-formers/salt-formers. A threefold increase in the solubility was observed in olanzapinium 3-hydroxybenzoate and olanzapinium anthranilate, and an almost fivefold increase in solubility of olanzapinium 2-aminoterephthalate.

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.

Ecofriendly chromatographic methods for determination of co-prescribed drugs, olanzapine and metformin, in rat plasma

Background: Olanzapine (OLZ) is one of most recommended drugs for the treatment of schizophrenia while metformin (MET) is the most commonly used hypoglycemic agent. Aim: Development and validation of two green, sensitive and accurate chromatographic methods for the simultaneous determination of OLZ along with the co-prescribed, MET. Materials & methods: TLC-densitometric method with a developing system consisting of methylene chloride:methanol:ethyl acetate:triethylamine (4:4:5:0.1, by volume) and a reversed-phase (RP)-HPLC method where the chromatographic separation was performed using ethanol:water mixture (50: 50, v/v) as a mobile phase. Results: TLC-densitometric method had linearity over concentration ranges of 160-4000 ng/band for OLZ and 150-4500 ng/band for MET, while RP-HPLC method was linear and validated over concentration range of 300-20000 ng/ml for OLZ and MET. Conclusion: Pharmacokinetic study was successfully performed and suggested the possibility of co-administration of MET with OLZ and their further formulation in one pharmaceutical preparation to enhance patient's compliance.

Design and Development of Liquid Drug Reservoirs for Microneedle Delivery of Poorly Soluble Drug Molecules

The poor aqueous solubility of existing and emerging drugs is a major issue faced by the pharmaceutical industry. Water-miscible organic solvents, termed co-solvents, can be used to enhance the solubility of poorly soluble substances. Typically, drugs with poor aqueous solubility and Log P > 3 are not amenable to delivery across the skin. This study investigated the use of co-solvents as reservoirs to be used in combination with hydrogel-forming microneedles to enhance the transdermal delivery of hydrophobic compounds, namely Nile red, olanzapine and atorvastatin. A custom-made Franz cell apparatus was fabricated to test the suitability of a liquid drug reservoir in combination with polymeric microneedles. A co-solvency approach to reservoir formulation proved effective, with 83.30% ± 9.38% of Nile red dye, dissolved in 1 mL poly(ethylene glycol) (PEG 400), permeating neonatal porcine skin over 24 h. PEG 400 and propylene glycol were found to be suitable reservoir media for olanzapine and atorvastatin, with approximately 50% of each drug delivered after 24 h. This work provides crucial proof-of-concept evidence that the manipulation of microneedle reservoir properties is an effective method to facilitate microneedle-mediated delivery of hydrophobic compounds.

Graphene/graphite paste electrode incorporated with molecularly imprinted polymer nanoparticles as a novel sensor for differential pulse voltammetry determination of fluoxetine

Molecularly imprinted polymer (MIP) nanoparticles including highly selective recognition sites for fluoxetine were synthesized, utilizing precipitation polymerization. Methacrylic acid and vinyl benzene were used as functional monomers. Ethylene glycol dimethacrylate was used as cross-linker agent. The obtained polymeric nanoparticles were incorporated with carbon paste electrode (CPE) in order to construct a fluoxetine selective sensor. The response of the MIP-CP electrode to fluoxetine was remarkably higher than the electrode, modified with the non-imprinted polymer, indicating the excellent efficiency of the MIP sites for target molecule recognition. It was found that the addition of a little amount of graphene, synthesized via modified hummer's method, to the MIP-CP resulted in considerable enhancement in the sensitivity of the electrode to fluoxetine. Also, the style of electrode components mixing, before carbon paste preparation, was demonstrated to be influential factor in the electrode response. Some parameters, affecting sensor response, were optimized and then a calibration curve was plotted. A dynamic linear range of 6×10(-9)-1.0×10(-7)molL(-1) was obtained. The detection limit of the sensor was calculated equal to 2.8×10(-9)molL(-1) (3Sb/m). This sensor was used successfully for fluoxetine determination in the spiked plasma samples as well as fluoxetine capsules.

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.