Validated sensitive spectrofluorimetric method for determination of antihistaminic drug azelastine HCl in pure form and in pharmaceutical dosage forms: application to stability study

A highly sensitive, simple and rapid spectrofluorimetric method was developed for the determination of azelastine HCl (AZL) in either its pure state or pharmaceutical dosage form. The proposed method was based on measuring the native fluorescence of the studied drug in 0.2 M H₂SO₄ at λ_em = 364 nm after excitation at λ_ex = 275 nm. Different experimental parameters were studied and optimized carefully to obtain the highest fluorescence intensity. The proposed method showed a linear dependence of the fluorescence intensity on drug concentration over a concentration range of 10–250 ng/mL, with a limit of detection of 1.52 ng/mL and limit of quantitation of 4.61 ng/mL. Moreover, the method was successfully applied to pharmaceutical preparations, with percent recovery values (± SD) of 99.96 (± 0.4) and 100.1 (± 0.52) for nasal spray and eye drops, respectively. The results were in good agreement with those obtained by the comparison method, as revealed by Student's t‐test and the variance ratio F‐test. The method was extended to study the stability of AZL under stress conditions, where the drug was exposed to neutral, acidic, alkaline, oxidative and photolytic degradation according to International Conference on Harmonization (ICH) guidelines. Copyright © 2016 John Wiley & Sons, Ltd.     

Simeprevir oxidative degradation product: Molecular modeling,in silico toxicity and resolution by synchronous spectrofluorimetry

In this article, one of the potential degradation products of the novel antiviral drug simeprevir was isolated and characterized by means of infrared (IR) and mass spectrometry. Moreover, comparative molecular docking, ADMET (absorption, distribution, metabolism, excretion – toxicity) and insilico toxicity prediction studies were applied to evaluate the activity of simeprevir and its degradation product. Furthermore,a simple, accurate and selective second derivative synchronous spectrofluorimetric method was developed for the determination of simeprevir in the presence of its oxidative degradation product.The synchronous fluorescence spectra of both compounds were measured in ethanol at pH 2.0 usingΔλ of 140 nm and the peak amplitude of the second derivative spectra were measured at 442 nm. The method was rectilinear over the concentration range of 0.2 to 2.0 μg/ml and validated according to the ICH (International Conference on Harmonization) guidelines. Moreover, the method was statistically compared to the reverse‐phase high‐performance liquid chromatography (RP‐HPLC) method and good results were obtained.     

cPPB‐aE is discovered from photosynthetic benthic dinoflagellates

Although chlorophyll degradation pathways in higher plants have been well studied, little is known about the mechanisms of chlorophyll degradation in microalgae. In this article, we report the occurrence of a chlorophyll a derivative that has never been discovered in photosynthetic organisms. This chlorophyll derivative emits no fluorescence and has a peculiar absorbance peak at 425, 451, 625, and 685 nm. From these features, it was identified as 13²,17³‐cyclopheophorbide a enol (cPPB‐aE), reported as a degradation product of chlorophyll a derived from prey algal cells in heterotrophic protists. We discovered cPPB‐aE in six benthic photosynthetic dinoflagellates that are phylogenetically separated into four clades based on SSU rDNA molecular phylogeny. This is the first report of this chlorophyll derivative in photosynthetic organisms and we suggest that the derivative is used to quench excess light energy.     

Micelle‐enhanced direct spectrofluorimetric method for the determination of linifanib: Application to stability studies

A new simple stability‐indicating spectrofluorimetric method has been developed and validated for the determination of the tyrosine kinase inhibitor, linifanib (LNF). The proposed method makes use of the native fluorescence characteristics of LNF in a micellar system. Compared with aqueous solutions, the fluorescence intensity of LNF was greatly enhanced upon the addition of Tween‐80. The relative fluorescence intensity of LNF was measured in a diluting solvent composed of 2% Tween‐80: phosphate buffer pH 8.0 (20: 80, v/v) using excitation and emission wavelengths of 290 and 450 nm, respectively. The proposed method was fully validated as per the ICH guidelines. The recorded fluorescence intensity of LNF was rectilinear over a concentration range of 0.3–2 μg/ml with a high correlation coefficient (r = 0.9990) and low limits of detection (0.091 μg/ml) and quantitation (0.275 μg/ml). The applicability of the method was extended to study the inherent stability of LNF under different stress degradation conditions including, alkaline, acidic, oxidative, photolytic and thermal degradation. Moreover, the method was utilized to study the kinetics of the alkaline and oxidative degradation of LNF. The pseudo‐first order rate constants and half‐lives were calculated.     

Enantiomeric assay of escitalopram S(+)‐enantiomer and its “in‐process impurities” using two different techniques

The enantiomeric purity of escitalopram oxalate ESC and its “in‐process impurities,” namely, ESC‐N‐oxide, ESC‐citadiol, and R(?)‐enantiomer were studied in drug substance and products using high‐performance liquid chromatography (HPLC)‐UV (Method I), synchronous fluorescence spectroscopy (SFS) (Method IIA), and first derivative SFS (Method IIB). Method I describes as an isocratic HPLC‐UV for the direct resolution and determination of enantiomeric purity of ESC and its “in‐process impurities.” The proposed method involved the use of α_l‐acid glycoprotein (AGP) chiral stationary phase. The regression plots revealed good linear relationships of concentration range of 0.25 to 100 and 0.25 to 10 μg mL^?1 for ESC and its impurities. The limits of detection and quantifications for ESC were 0.075 and 0.235 μg mL^?1, respectively. Method II involves the significant enhancement of the fluorescence intensities of ESC and its impurities through inclusion complexes formation with hydroxyl propyl‐β‐cyclodextrin as a chiral selector in Micliavain buffer. Method IIA describes SFS technique for assay of ESC at 225 nm in presence of its impurities: R(?)‐enantiomer, citadiol, and N‐oxide at ?λ of 100 nm. This method was extended to (Method IIB) to apply first derivative SFS for the simultaneous determination of ESC at 236 nm and its impurities: the R(?)‐enantiomer, citadiol, and N‐oxide at 308, 275, and 280 nm, respectively. Linearity ranges were found to be 0.01 to 1.0 μg mL^?1 for ESC and its impurities with lower detection and quantification limits of 0.033/0.011 and 0.038/0.013 μg mL^?1 for SFS and first derivative synchronous fluorescence spectra (FDSFS), respectively. The methods were used to investigate the enantiomeric purity of escitalopram.     

Indirect synchronous fluorescence spectroscopy and direct high‐performance thin‐layer chromatographic methods for enantioseperation of zopiclone and determination of chiral‐switching eszopiclone: Evaluation of thermodynamic quantities of chromatographic separation

Economic and enantioselective synchronous fluorescence spectroscopy and high‐performance thin‐layer chromatography methods have been developed and validated as per ICH guidelines for the separation of zopiclone enantiomers using L‐(+)‐tartaric acid as a chiral selector, followed by determination of the chiral‐switching eszopiclone. Synchronous fluorescence spectroscopy was successfully applied for chiral recognition of R & S enantiomers of zopiclone at ?λ = 110 nm based on creating of diastereomeric complexes with 0.06M tartaric acid in an aqueous medium containing 0.2M disodium hydrogen orthophosphate. Synchronous fluorescence intensities of eszopiclone were recorded at 296 nm in concentration range 0.2‐ to 4‐μg/mL eszopiclone. High‐performance thin‐layer chromatography method depends on resolution of zopiclone enantiomers on achiral HPTLC silica‐gel plates using acetonitrile:methanol:water (8:2:0.25, v/v/v) containing L‐(+)‐tartaric acid as a chiral mobile‐phase additive followed by densitometric measurements at 304 nm in concentration range of 1 to 10 μg/band of eszopiclone. The effect of chiral‐selector concentration, pH, and temperature on the resolution have been studied and optimized for the proposed methods. The cited procedures were successfully applied to determine eszopiclone in commercial tablets of pure and racemic forms. Enantiomeric excess was evaluated using optical purity test and integrated peak area to describe the enantiomeric ratio. Thermodynamics of chromatographic separation, enthalpy, and entropy were evaluated using the Van't Hoff equation. The proposed methods were found to be selective for identification and determination of the eutomer in drug substances and products.     

Spectrofluorimetric Method for the Determination of Doxepin Hydrochloride in Commercial Dosage Forms

A novel spectrofluorimetric method has been developed for the determination of doxepin hydrochloride in commercial dosage forms. The method is based on the fluorescent ion pair complex formation of the drug with eosin Y in the presence of sodium acetate–acetic acid buffer solution of pH 4.52 which is extractable in dichloromethane. The extracted complex showed fluorescence intensity at λ_em = 567 nm after excitation at 464 nm. The calibration curve was linear over the working range of 0.1–0.8 μg ml⁻¹. Under the optimized experimental conditions, present method is validated as per International Conference on Harmonization guidelines. The limit of detection for the developed method is 2.95 ng ml⁻¹. The method has been successfully applied to the determination of doxepin hydrochloride in commercial dosage forms. The results are compared with the reference spectrofluorimetric method.     

Spectrofluorimetric determination of oseltamivir phosphate through derivatization with o‐phthalaldehyde. Application to pharmaceutical preparations with a preliminary study on spiked plasma samples

A simple and sensitive spectrofluorimetric method has been developed and validated for the determination of oseltamivir phosphate (OST) in pharmaceutical preparations. The method is based on the reaction between oseltamivir phosphate and o‐phthalaldehyde in presence of 2‐mercapto‐ethanol in borate buffer, pH 10.8, to give a highly fluorescent product measured at 450 nm after excitation at 336 nm. The different experimental parameters affecting the development and stability of the reaction product were studied and optimized. The fluorescence intensity–concentration plot is rectilinear over the range 0.05–1.0 µg/mL, with a lower detection limit of 5 ng/mL and limit of quantitation of 16 ng/mL. The developed method was successfully applied to the analysis of the drug in its commercial capsules and suspension, mean recoveries of OST were 99.97 ± 1.67% and 100.17 ± 1.18%, respectively (n = 3). Statistical comparison of the results obtained by the proposed and comparison method revealed no significant difference in the performance of the two methods regarding accuracy and precision. The proposed method was further extended to in vitro determination of the studied drug in spiked human plasma as a preliminary investigation; the mean recovery (n = 3) was 98.68 ± 5.8%. A reaction pathway was postulated. Copyright © 2012 John Wiley & Sons, Ltd.     

Second‐derivative synchronous spectrofluorimetric assay of dapagliflozin: Application to stability study and pharmaceutical preparation

A highly accurate, simple and sensitive spectrofluorimetric analytical method for dapagliflozin (DGF) quantitation was developed. The proposed method was successively applied to DGF analysis in both its pure and pharmaceutical dosage forms. This method was developed to investigate DGF stability in its degradation products, as laid out in International Council for Harmonisation (ICH) rules. Kinetics of alkaline degradation of DGF was also calculated. The half‐life time (t_1/2) of the reaction was 75.32 min. An alkaline degradation pathway was described. The present study involved measurement of the second‐derivative synchronous fluorescence intensity of DGF at Δλ = 30 nm. Peak amplitude was measured at 322 nm. Linear range of the calibration curve was 0.1–1.0 μg ml^?1. Lower detection and quantitation limits were 0.023 and 0.071 μg ml^?1, respectively, and indicated good sensitivity of the proposed method. Mean per cent recovery was 99.78 ± 1.78%. The proposed analytical approach was successfully applied to DGF in the quality control laboratory and would be suitable as a stability‐indicating assay.     

Dental Mold: A Novel Formulation to Treat Common Dental Disorders

Oral administration of antibiotics to treat dental problems mostly yields slow actions due to slow onset and hepatic “first-pass.” Again, commonly used dental paints are generally washed out by saliva within few hours of application. To overcome the challenges, polymeric molds to be placed on an affected tooth (during carries and gum problems) were prepared and evaluated in vitro for sustained drug release for prolonged local action. Here, amoxicillin trihydrate and lidocaine hydrochloride were used as model drugs. Dental molds were prepared using corn zein, carbopol 934 P, gum karaya powder, and poloxamer 407 by mixing and solvent evaporation technique. Different physicochemical evaluation studies such as tooth adhesion test, surface pH, swelling index, and drug-distribution pattern were carried out. Percentage swelling varied from 56% to 93%. Average tooth adhesion strength and mean initial surface pH of the formulations were 50 g and 6.5, respectively. As assessed by scanning electron microscopy, drug distribution was uniform throughout the matrix. Cumulative percentage release of lidocaine hydrochloride and amoxicillin trihydrate in simulated saliva were 98% and 50%, respectively. In vitro drug-release studies revealed the sustained-release patterns of the drugs in simulated saliva at least for 24 h. The stability study shows that the drugs were stable in the formulations following the conditions as per ICH guideline. The formulation is a novel approach to deliver the drug(s) for a prolonged period for local action upon its application on an affected tooth.     

Spectrofluorimetric determination of certain adrenergic agonist drugs in their pure forms and pharmaceutical formulations: Content uniformity test application

A new, simple, sensitive and rapid spectrofluorimetric method has been developed for determination of certain adrenergic agonists such as isoxsuprine hydrochloride, ritodrine hydrochloride and etilefrine hydrochloride in their pure forms and pharmaceutical dosage forms. The method depends on micellar enhancement of the native fluorescence of investigated drugs by using 2% w /v sodium dodecyl sulfate (SDS) as an anionic surfactant. The enhanced fluorescence intensity of investigated drugs was measured at 305 nm after excitation at 278 nm. The interaction of studied drugs with SDS was studied, and the enhanced fluorescence intensity was exploited to develop an assay method for the determination of investigated drugs. The relative fluorescence intensity–concentration plots were rectilinear over the range 0.15–3.00 μg ml^?1, with low quantification limits of 0.132, 0.123 and 0.118 μg mL^?1 for isoxsuprine, ritodrine and etilefrine, respectively. The proposed method was successfully applied for determination of studied drugs in their pharmaceutical formulations. Moreover, the high sensitivity of the proposed method allows performing the content uniformity testing of the studied drugs in their tablets by using the official United States Pharmacopeia (USP) guidelines. Statistical comparisons of the results with those of the reported methods revealed excellent agreement and indicated no significant difference in accuracy and precision.     

Spectrofluorimetric method for the determination of sulpiride in pharmaceutical preparations and human plasma through derivatization with 2‐cyanoacetamide

A sensitive and accurate spectrofluorimetric method has been developed for the determination of sulpiride in pharmaceutical preparations and human plasma. The developed method is based on the derivatization reaction of 2‐cyanoacetamide with sulpiride in 30% ammonical solution. The fluorescent derivatized reaction product exhibited maximum fluorescence intensity at 379 nm after excitation at 330 nm. The optimum conditions for derivatization reactions were studied and the fluorescence intensity versus concentration plot was found to be linear over the concentration range 0.2–20.0 µg/mL with a correlation coefficient of 0.9985. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.82 and 2.73 ng/mL, respectively. The proposed method was validated according to ICH guidelines. The effects of common excipients and co‐administered drugs were also studied. The accuracy of the method was checked using the standard addition method and percent recoveries were found to be in the range of 99.00–101.25% for pharmaceutical preparations and 97.00–97.80% for spiked human plasma. The method was successfully applied to commercial formulations and the results obtained for the proposed method were compared with a high‐performance liquid chromatography reference method and statistically evaluated using the Student's t‐test for accuracy and the variance ratio F‐test for precision. A reaction pathway was also proposed. Copyright © 2012 John Wiley & Sons, Ltd.     

Green spectrophotometric and spectrofluorimetric determination of biperiden hydrochloride using erythrosine B sensing probe

Erythrosine B (EB) is a food colorant antiviral xanthene dye that has many applications as a color additive in pharmaceuticals and cosmetics. Its use as a sensor for spectrofluorimetric and spectrophotometric analysis of amine-based pharmaceuticals renders many advantages because of its availability, low cost, rapid labeling, and high sensitivity. Herein, two fast and sensitive spectrofluorimetric and spectrophotometric methods were established for the estimation of the anti-Parkinson drug, biperiden (BIP) hydrochloride (HCl), in its raw material and tablet forms. The proposed methods depended on the interaction between the phenolic group of EB and the tertiary amino group of the studied analyte to form an ion-pair complex at pH 4 using the Britton Robinson buffer. The spectrofluorimetric method is based on the measurement of the quenching power of BIP HCl on the fluorescence intensity of EB at λ_ex/em = 527.0/550.9 nm. This method was rectilinear over the concentration range of 0.1–1.0 μg/mL with a limit of detection (LOD) = 0.017 μg/mL and a limit of quantification (LOQ) = 0.05 μg/mL. Meanwhile, the colorimetric method involved monitoring the absorbance of the formed ion-pair complex at 555 nm, showing a linearity range of 0.4–5.0 μg/mL with LOD = 0.106 μg/mL and LOQ = 0.322 μg/mL. The proposed methods were assessed for the greenness, indicating the greenness of the developed methods.     

Selective spectrofluorimetric method for determination of Lisinopril in pharmaceutical preparations and in presence of hydrochlorothiazide: Application to content uniformity testing

A novel sensitive and cost‐effective spectrofluorimetric method has been developed and validated for determination of lisinopril (an angiotensin converting enzyme inhibitor) in its pure form and pharmaceutical preparations. The method is based on the reaction of the drug with ninhydrin and phenylacetaldehyde in buffered medium (pH 7.0) to form a highly fluorescent product measured at 460 nm after excitation at 390 nm. Different experimental parameters were optimized and calibration curve was constructed. The fluorescence‐concentration relationship was linear in the range of 0.15–4.0 μg mL^?1. The calculated Limit of detection (LOD) and Limit of quantitation (LOQ) were 0.04 and 0.12 μg mL^?1, respectively. The method was successfully applied for the analysis of pharmaceutical preparations containing the studied drug either alone or co‐formulated with hydrochlorothiazide. The obtained results were in agreement with those of the reported method in respect to accuracy and precession. Moreover, the method was applied content uniformity testing according to United States Pharmacopeia (USP) guidelines.     

An eco‐friendly direct spectrofluorimetric method for the determination of irreversible tyrosine kinase inhibitors,neratinib and pelitinib: application to stability studies

A new rapid and simple stability‐indicating spectrofluorimetric method has been developed for the determination of two irreversible tyrosine kinase inhibitors (TKIs), neratinib (NER) and pelitinib (PEL). The method is based upon measurement of the native fluorescence intensity of both drugs at λ_ex 270 nm in aqueous borate buffer solutions (pH 10.5). The fluorescence intensity recorded at 545 nm (NER) and 465 nm (PEL) were rectilinear over the concentration range of 0.1–10 μg/mL for both drugs with a high correlation coefficient (r > 0.999). The proposed method provided low limits of detection and of quantitation of 0.07, 0.11 μg/mL (NER) and 0.02, 0.05 μg/mL (PEL), respectively. The method was successfully applied for the determination of NER and PEL in bulk powder. The proposed methods were fully validated as per the International Conference on Harmonisation (ICH) guidelines. The application of the method was extended to stability studies of both NER and PEL under different forced‐degradation conditions (acidic‐induced, base‐induced, oxidative, wet heat, and photolytic degradation). Moreover, the kinetics of the base‐induced and oxidative degradation of both drugs was investigated and the pseudo‐first‐order rate constants and half‐lives were estimated at different temperatures. Also, an Arrhenius plot was applied to predict the stability behaviour of the two drugs at room temperature. Copyright © 2016 John Wiley & Sons, Ltd.     

Application of quinone‐based fluorophore and native fluorescence for the spectrofluorimetric determination of agomelatine in dosage form: Identification of acidic and alkaline‐ induced degradation products by LC–MS/TOF

Three spectrofluorimetric methods were developed for agomelatine (AGM) determination in commercial tablets. Method A is based on measuring the native fluorescence of AGM aqueous solution at 230/360 nm. Methods B and C are based on the formation of a charge transfer complex between AGM and 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and 7,7,8,8‐tetracyanoquinodimethane (TCNQ) with measurement of the formed fluorophore at 365/475 nm and 250/304 nm, respectively. The relative fluorescence intensity (RFI) of AGM–DDQ complex was greatly enhanced in the presence of methyl‐β‐cyclodextrin (CD). The methods were linear over the concentration ranges of 0.015–0.5, 0.5–8.0, 0.09–6.0 and 0.05–0.2 μg/ml for AGM‐native fluorescence, AGM–DDQ, AGM–DDQ–CD and AGM–TCNQ complexes, respectively with excellent correlation coefficients (r = 0.9999). The methods were validated as per the International Conference on Harmonization (ICH) guidelines and all validation requirements were satisfied. The developed methods were extended to the analysis of AGM in commercial tablets. Furthermore, the stability of AGM was studied under different stress conditions (alkaline, acidic, oxidative and photolytic). The potential alkaline and acidic degradation products were identified by LC–MS/TOF.     

Rapid and visual detection for hypochlorite of an AIE enhanced fluorescence probe

In this paper, a new ‘turn‐on' fluorescence probe for the rapid, sensitive, and visual detection of hypochlorite is reported. The push–pull type trianiline–tricyanofuran‐based fluorescent probe was prepared using a condensation reaction between tricyanofuran and the thiophene–trianiline derivative that had high quantum yields and showed aggregation‐induced emission enhanced properties. Upon exposure to hypochlorite, prominent fluorescence enhancement of the probe was observed via the release of the fluorophore from the probe. The probe showed a ratiometric absorption change at 315 nm and 575 nm. Importantly, the probe showed an excellent detection limit for hypochlorite at 1.2 × 10^?7 M in solution and it was successfully applied for monitoring hypochlorite in waste water by test strip. This work reports a new fluorescence analytical sensing method for hypochlorite that has potential practical value in environmental monitoring and biological discrimination.     

A ratiometric fluorescence strategy based on copper nanoclusters/carbon dots for sensitive detection of doxorubicin

Sensitive detection of doxorubicin (DOX) is critical for clinical theranostics. A novel ratiometric fluorescence strategy based on the inner filter effect (IFE) has been established for the sensitive detection of DOX by designing a ratiometric fluorescence probe. In the presence of DOX, the fluorescence intensity of copper nanoclusters (CuNCs) at 485 nm decreases, and the fluorescence intensity of carbon dots at 560 nm increases. Therefore, DOX can be quantitatively detected by measuring the ratio of the fluorescence intensities at 560 and 485 nm (F₅₆₀/F₄₈₅). The F₅₆₀/F₄₈₅ ratio exhibits a linear correlation with the DOX concentration in the range from 1.0 × 10⁻⁸ M to 1.0 × 10⁻⁴ M with the detection limit of 3.7 nM. Furthermore, this method was also successfully applied to the analysis of DOX in human plasma samples, affording an effective platform for drug safety management.     

Spectrofluorimetric determination of certain biologically active phenothiazines in commercial dosage forms and human plasma

A validated simple and sensitive spectrofluorimetric method was developed for the determination of chlorpromazine hydrochloride, promethazine hydrochloride, trifluperazine hydrochloride, thioridazine hydrochloride, perazine maleate and oxomemazine. The method was based on condensation of malonic acid/acetic anhydride (MAA) under the catalytic effect of the tertiary amine moiety of the studied phenothiazines to provide a deep yellow to brown colour with green florescence. Relative fluorescence intensity of the products was measured at λ_exc 398 nm and λ_em 432 nm. Different variables affecting the reaction were studied and optimized. The method was successfully applied for the determination of the studied drugs in commercial dosage forms. The lower detection limits allowed the application of this method for the determination of the compounds in plasma as an example of a biological fluid. In addition, the method was considered specific for the determination of tertiary amines in the presence of primary and secondary amines; as a result, it was deemed suitable for the determination of the cited drugs in the presence of their degradation products resulting from N‐dealkylation or oxidation of the corresponding sulphoxides or sulphones. Copyright © 2012 John Wiley & Sons, Ltd.     

Elucidating the interaction of clofazimine with bovine liver catalase; a comprehensive spectroscopic and molecular docking approach

Nowadays, understanding of interface between protein and drugs has become an active research area of interest. These types of interactions provide structural guidelines in drug design with greater clinical efficacy. Thus, structural changes in catalase induced by clofazimine were monitored by various biophysical techniques including UV‐visible spectrometer, fluorescence spectroscopy, circular dichroism, and dynamic light scattering techniques. Increase in absorption spectra (UV‐visible spectrum) confers the complex formation between drug and protein. Fluorescence quenching with a binding constants of 2.47 × 10⁴ M⁻¹ revealed that clofazimine binds with protein. Using fluorescence resonance energy transfer, the distance (r ) between the protein (donor) and drug (acceptor) was found to be 2.89 nm. Negative Gibbs free energy change (ΔG °) revealed that binding process is spontaneous. In addition, an increase in α‐helicity was observed by far‐UV circular dichroism spectra by adding clofazimine to protein. Dynamic light scattering results indicate that topology of bovine liver catalase was slightly altered in the presence of clofazimine. Hydrophobic interactions are the main forces between clofazimine and catalase interaction as depicted by molecular docking studies. Apart from hydrophobic interactions, some hydrogen bonding was also observed during docking method. The results obtained from the present study may establish abundant in optimizing the properties of ligand‐protein mixtures relevant for numerous formulations.