A Stability-Indicating HPLC Method for the Determination of Fingolimod in Pharmaceutical Dosage Forms

Azobisisobutyronitrile loaded on mesoporous silica particles: A new stressor for solid-state oxidative forced degradation studies

A new approach for testing drug sensitivity to autooxidative degradation in the solid state is demonstrated in this work. A novel solid-state form of stressing agent for autooxidation has been proposed, based on azobisisobutyronitrile loaded into mesoporous silica carrier particles. The new solid-state form of the stressing agent was applied in degradation studies of two active pharmaceutical ingredients: bisoprolol and abiraterone acetate. The effectiveness and predictivity of the method were evaluated by comparing impurity profiles with those obtained by traditional stability testing of commercial tablets containing the investigated APIs. The results obtained by the new solid-state stressor were also compared with those obtained by an existing method for testing peroxide oxidative degradation in the solid state using a complex of polyvinylpyrrolidone with hydrogen peroxide. It was found that the new silica particle-based stressor was able to effectively predict which impurities could be formed by autooxidation in tablets and that this new approach is complementary to methods for testing peroxide oxidative degradation known from the literature.

CDX-modified chitosan nanoparticles remarkably reduce therapeutic dose of fingolimod in the EAE model of mice

Fingolimod (Fin), an FDA-approved drug, is used to control relapsing-remitting multiple sclerosis (MS). This therapeutic agent faces crucial drawbacks like poor bioavailability rate, risk of cardiotoxicity, potent immunosuppressive effects, and high cost. Here, we aimed to assess the therapeutic efficacy of nano-formulated Fin in a mouse model of experimental autoimmune encephalomyelitis (EAE). Results showed the suitability of the present protocol in the synthesis of Fin-loaded CDX-modified chitosan (CS) nanoparticles (NPs) (Fin@CSCDX) with suitable physicochemical features. Confocal microscopy confirmed the appropriate accumulation of synthesized NPs within the brain parenchyma. Compared to the control EAE mice, INF-γ levels were significantly reduced in the group that received Fin@CSCDX (p < 0.05). Along with these data, Fin@CSCDX reduced the expression of TBX21, GATA3, FOXP3, and Rorc associated with the auto-reactivation of T cells (p < 0.05). Histological examination indicated a low-rate lymphocyte infiltration into the spinal cord parenchyma after the administration of Fin@CSCDX. Of note, HPLC data revealed that the concentration of nano-formulated Fin was about 15-fold less than Fin therapeutic doses (TD) with similar reparative effects. Neurological scores were similar in both groups that received nano-formulated fingolimod 1/15th of free Fin therapeutic amounts. Fluorescence imaging indicated that macrophages and especially microglia can efficiently uptake Fin@CSCDX NPs, leading to the regulation of pro-inflammatory responses. Taken together, current results indicated that CDX-modified CS NPs provide a suitable platform not only for the efficient reduction of Fin TD but also these NPs can target the brain immune cells during neurodegenerative disorders.

Development and validation of three colorimetric charge transfer complexes for estimation of fingolimod as an antineoplastic drug in pharmaceutical and biological samples

An inexpensive, simple, sensitive and validated approach is developed for estimation of fingolimod through production of colored charge transfer complexes of fingolimod with different electron acceptor reagents, including a reaction of fingolimod as n-donor with 7,7,8,8-tetracyanoquinodimethane, tetrachloro 1,4-benzoquinone and tetracyanoethylene and as n-acceptors, yielding colored and stable anions which were measured spectrophotometrically. The range that obeyed Beer’s law is 50–300 µg mL−1 for fingolimod with all the studied reagents. The various parameters that affect the reaction were studied and optimized. The results were statistically compared with a reported method showing equal precision and accuracy. The researched approaches were utilized to determine the cited drug in its pharmaceutical form and spiked human plasma with accepted accuracy and precision.

Spectrofluorimetric analysis of fingolimod via complex formation with eosin Y in its pure form, pharmaceutical preparation and biological samples

This work discuss a simple, rapid, accurate, precise, sensitive, validated and effective cost spectrofluorometric method. The technique was applied for the analysis of fingolimod hydrochloride (FIN) in pure form, capsules, human plasma and urine samples. Formation of binary complex between the suggested amino group of (FIN) with Eosin Y (EOY) is the principle of its determination. FIN was determined spectrofluorimetrically by measuring its quenching effect on the EOY native fluorescence at 575 nm after excitation at 525 nm. The fluorescence-concentration linearity was 0.1-1.0 µg mL^-1. The suggested spectrofluorimetric results have been certified according to ICH regulations and were applied for analysis of FIN in capsules, human plasma and urine samples. The validated results were accepted compared to reference method.