Int J Pharm Pharm Sci, Vol 9, Issue 12, 1-9Review Article



Department of General Studies, Jubail Industrial College, P. O. Box 10099, Jubail Industrial City 31961, Saudi Arabia

Received: 16 Jun 2017 Revised and Accepted: 02 Nov 2017


Globally, dyes are widely used in the pharmaceutical, food, textile, cosmetics, plastics, leather, paint, ink and paper industries. Eosin is an acidic orange-pink dye and has very strong staining properties. Haematoxylin and eosin Y (H and E) combination is the most common staining and primary diagnostic technique in histo-pathological laboratories. This review mainly discussed the utility of eosin dye in quality control laboratories as an ion pairing agent for drug analysis. Eosin Y is one the most common ion pairing agent and its mono and di anionic forms are capable of interacting with many drug molecules to form colored/fluorescent binary or ternary complexes that can be analyzed with or without extraction by spectrofluorimetry and/or spectrophotometry. Quenching fluorescence and advantages of spectrofluorimetry over spectrophotometry were also discussed. Fluorescence detection greatly enhances the sensitivity and providing a sensitive and relatively inexpensive instrumental method of analysis using eosin Y for various important drugs in pure, commercial dosage forms and biological fluids.

Keywords: Eosin Y, Ion pairing agent, Binary and ternary complexes, Commercial dosage forms


Dyes are natural or synthetic colored organic substances which have the affinity to impart color to various substrates by absorbing into the substrate. In general, the dye molecules are chemically bonded to the surface and become a part of the material on which it is applied. Dyes are widely used in the pharmaceutical, food, textile, cosmetics, plastics, leather, paint, ink and paper industries [1]. A class of dye called xanthene is classified into three subgroups. One of the subgroups is called fluorone dyes that include fluorescein, erythrosine and rhodamine.

Eosin dyes are bromine derivative of fluorescein which has two very closely related dyes commonly known as Eosin yellowish (Eosin Y) and Eosin bluish (Eosin B) as shown in fig. 1. Eosin Y is a tetrabromo derivative whereas eosin B is a dibromo dinitro derivative of fluorescein.

Fig. 1: Structure of eosins

Eosin Y is chemically known as disodium 2-(2, 4, 5, 7-tetrabromo-6-oxido-3-oxo-3H-xanthen-9-yl) benzoate have a molecular formula (C20H6Br4Na2O5) and molar mass 691.85. Fluorescein in the eosin Y molecule called fluorochrome exists in two forms; one is the more stable quinoid form which is colored and fluorescent while the other one is lactone form which is colorless and non-fluorescent presented as shown A and B respectively, in fig. 2 [2]. Disodium salt of eosin Y can be readily converted into free acid in which the free carboxylic acid group (quinoid form) exists in equilibrium with its lactone form. In a weakly acidic medium, ionization of eosin Y may take place either by dissociation of hydroxyl or carboxylic group.

It was reported that hydroxyl group dissociates easily compare to the carboxylic acid group. In solution, eosin Y can exist in three different forms as neutral (H2R), monoanionic (HR-) and di anionic (R2-) forms, where R denotes the anionic part of the eosin Y as explained in fig. 3 [3-4]. The ionization constants (pKa1 and pKa2) of eosin Y were reported as 2.9 and 4.5 [5].

Eosin Y is a Biological Stain Commission certified dye. The HandE stains the most common and primary diagnostic technique in histo-pathological laboratories to stain cells and cytoplasm, collagen and muscle fibers. H and E staining method was also used in structure determination of grasshopper and mammalian testis as well as supporting structure determination of destruction of dental tissues [6]. Eosin was utilized as a fluorescent indicator in acid-base titration for the determination of vitamins (B1 and B2) in food [7]. Due to its strong staining properties, it has been used in various industrial applications such as color filter, liquid crystal display, paper inks, photographic materials, laundry detergent, cosmetics, pencil lead, pigments, varnish and textiles. It is also used in medicine as an important radioactive tracer.

Literature surveys reported that the mono or di anionic forms of eosin Y are capable of interacting with a cationic form of the drug molecules by the electrostatic interaction and hydrophobic forces and forms either binary complex with drug molecule or a ternary complex with drug molecule and a metal [8].

Fig. 2: Different forms of fluorochrome (Eosin Y)

Fig. 3: Ionization of eosin Y and its three different forms (H2R, HR-and R2-) [3-4]

In recent years, eosin was used as photoredox catalyst in organic synthesis [9], Carbon-Carbon and Carbon–Phosphorous bond formation [10]. It was utilized in the cleavage of C-C double bond of styrene [11], binding and estimation of protein assay [12-14], antimalarial agent for drug resistant Plasmodium falciparum [15], activating agent in teeth whitening composition [16], tracer in groundwater studies [17], complexing agent in ternary ion-association complex nanoparticles [18-19], sensing material in preparation of eosin Y film modified glassy carbon electrode [20], photosensitizer in dye sensitized solar cells and topical agents for treatment of diaper dermatitis and interfering agent in measurement of serum vancomycin [21-23]. Indirect determination of histamine, an important compound in various physiological processes in humans was determined in fish samples, dairy products and alcoholic beverages complexation with Fe (III) and eosin Y [24]. Catalyst-free activation of peroxides through photoexcited electron under visible LED light irradiation was also performed using eosin Y as a model dye [25]. A highly selective and sensitive resonance light scattering detection approach was developed for the synchronous analysis of anthelmintics after reaction with eosin Y to form ion-association complexes and separated by high-performance liquid chromatography [26]. An environmentally useful method was developed to detect sodium dodecyl sulphate using eosin Y and polyethyleneimine complex [27].

Applicability of eosin Y in drug analysis

Several commercially available xanthene dyes have been successfully used in the analysis of many pharmaceutical compounds. Eosin Y is an acidic dye belongs to the xanthene group of dyes that has been widely used for the determination of several basic drugs through the formation of colored or fluorescent ion association complex using spectrophotometric and/or spectro-fluorimetric methods.

Formation of binary and ternary complexes

Binary ion association complexes formed between eosin and the drug molecules by electrostatic interaction. It was reported that the formation of binary complex increases the sensitivity of determination. It may decrease the fluorescence intensity of the native fluorescence of the eosin [28] without any permanent change in the molecule. The stability and fluorescence capacity of the ion association complexes were studied by using various acidic buffer solutions and dispersing agents. It was reported that pH is the critical factor which plays an important role on ionization of eosin Y. It was found that the fluorescence capacity of the ion association complex formed with eosin Y was increased up to certain pH values and then a decrease in the fluorescence intensity was occurred [29-31]. Dispersing agents also affect the stability of the complexes and prevents precipitation of the ion association complexes [32-33].

Ternary complex categorized into two major types, the one is mixed ligand complex and the other is an ion-association complex. Both types of ternary complex formation improve not only the sensitivity but also the selectivity as well. The sensitivity of the ternary complex can also enhance by the addition of surfactant that dissolves the ternary complex and measured directly without involving extraction process. In general, a ternary complex has formula LnMxSy, where L stands for main ligand i.e. cited drug, M is the metal and S is the eosin Y, respectively.

The mechanism of ternary complex formation includes coordinate bond formation between metal ion and the cited drug molecule through atoms carrying lone pairs of electrons, and subsequently, a ternary complex is formed by interaction with eosin Y. The major advantage of ternary complex formation that it often has higher values of molar absorptivity and therefore improves the sensitivity of the method. Metal chelates formation also promotes the fluorescence and forms a ternary complex with eosin Y which can be utilized in the indirect determination of metals using atomic absorption spectrophotometric technique. These complexes are extractable with organic solvents such as chloroform and methylene chloride and have been widely utilized in the analysis of several pharmaceuticals. Eosin Y was used for determination of various pharmaceutical compounds using spectrophotometry and/or spectrofluorimetry through the formation of ternary complexes. However, the metal-drug and metal-eosin binary systems cannot be extracted in the same manner.

Quenching fluorescence

The term quenching refers to a process that decreases the fluorescence intensity of a given substance. It occurs during excited state lifetime and results in various types of molecular interactions. Collisional or dynamic quenching and static quenching are the two main types of quenching process. Both types of quenching require interaction between the fluorophore and quencher molecule. In dynamic quenching, the quencher molecule must diffuse to the fluorophore during excited state lifetime and upon contact, the fluorophore returns to the ground state without photon emission. Static quenching occurs when a fluorophore and quencher create a non-fluorescent complex before excitation of fluorophore [34]. Molecular oxygen, iodide, bromide ions and acrylamide are common quenchers for almost all dyes [35-38].

In addition to the above, apparent quenching can also occur due to the optical properties of the samples which are not much more useful. This trivial type of quenching occurs due to high optical densities or turbidity and can easily be controlled.

A separate type of quenching known as Fluorescence Resonance Energy Transfer (FRET) in which the intensity of the donor decreases and transfer to an acceptor molecule. The acceptor can be fluorescent or non-fluorescent. In both cases, the fluorescence intensity of the initially excited molecule is decreased. This type of quenching is often referred to as a donor-acceptor pair. It is mediated by the emission of a photon and it does not even require that the acceptor chromophore be fluorescent. During photosynthesis, a light antenna pigment uses resonance energy transfer to donate the collected energy to the photosynthetic reaction centre. This technique has led to qualitative and quantitative improvements, including increased spatial resolution and sensitivity. FRET is commonly used to measure distances within or between molecules in protein studies [39]. At present, FRET was used for measuring the structure [40-42], conformational changes [43] and interactions between molecules [44-45].

Applications of spectrofluorimetry in drug analysis using eosin

Spectrofluorimetry or fluorescence spectroscopy is a type of molecular emission spectroscopy and an extremely sensitive analytical method which has been widely applied for the determination of a variety of pharmaceutical compounds. It measures the fluorescence intensity which allows sensitive and selective quantitation of certain compounds which exhibit the fluorescence. This method involves measurement of enhanced or quenched fluorescent signals. It has been applied in three different processes: fluorescence, phosphorescence and chemiluminescence. Fluorescence is the most common luminescence process used in the pharmaceutical analysis. It involves photoexcitation process which occurs by absorption of various types of radiant energy such as UV-visible light and emission process in which emission radiant energy from an excited electronic state takes place as fluorescence within 10‑6 to 10-9 seconds. Mostly fluorescent molecules are aromatic in nature. However, substituents such as-NH2-OH,-F,-OCH3,-NHCH3 and N(CH3)2 groups, often enhances fluorescence while electron withdrawing groups containing halogen such as–Cl,-Br,-I, and-NHCOCH3,-NO2 or-COOH decrease or quench completely the fluorescence. Presence of dissolved oxygen, changes in buffer solutions of different pH values and solvent polarity also exhibit marked effect on the fluorescence of compounds.

This technique is important because of the fact that the intensity of light emitted by a fluorescent compound depends upon the concentration of that compound and hence, the measurement of fluorescence intensity permits the quantitative determination of trace contaminants of many inorganic species in the environment, industries and bodies. Fluorescence spectroscopy applied to drug analysis provides analytical methodologies with improved sensitivity, selectivity and range. It is one of the most important analytical methods in the field of chemistry, biology and chemical engineering. It is extensively used in nuclear research for the determination of uranium salts. It is also a method of the choice for the determination of many pharmaceutical compounds, plant pigments, hormones, food products, steroids and vitamins in formulations and biological fluids [46].

Taking the advantage of fluorescent properties of eosin Y, several researchers utilized eosin as a fluorescence quenching agent and analyses a variety of organic compounds. Eosin commonly used as an acidic red stain for highlighting cytoplasm material in samples. It forms either binary or ternary complex with pharmaceuticals and measured either directly without extraction or indirectly by extraction in an organic solvent. Many pharmaceutical compounds were analyzed using spectrofluorimetric technique involving eosin as a reactant. It was used in the analysis of various illicit drug samples encountered in small amounts [47]. Coumarins were determined in a well-known traditional Indian drug 'Shankhpushpi' [48], determination of scopoletin and mangiferin curcumin and testosterone in biological fluids [49-51].

The spectrofluorimetric method is less tedious and less cumbersome compared to chromatographic methods which require long run time and suffer from tedious operation procedures. Moreover, the high sensitivity and specificity offered by this method are also higher and the drug compounds can be analyzed up to nano levels. As data are shown in table 1, these methods were widely used in quantitation of many pharmaceuticals compounds using eosin Y due to its simplicity, low cost, high sensitivity and wide concentration range [52-68].

Applications of spectrophotometry in drug analysis using eosin

Spectrophotometry is a type of absorption spectroscopy. It involves measuring the amount of ultraviolet or visible light absorbed by a substance in solution. It is one of the most frequently used methods for the quantitation of pharmaceuticals due to its low cost, ease of operation and simplicity. It has been regarded as one of the most suitable and economical methods in research laboratories, hospitals and pharmaceutical industries. Visible region spectrophotometric methods found suitable for single component analysis [69, 70]. However, these methods were found not suitable for the multicomponent mixture. The instrumental development of ultraviolet region absorption spectrophotometry was reviewed and applied to solve multicomponent pharmaceutical mixture [71]. Eosin Y formed a binary or ternary colored nonfluorescent complexes were analyzed by spectrophotometry. A number of pharmaceutical compounds were analyzed using eosin Y as an ion pairing agent shown in table 2 [72-93].

Comparison of spectrofluorimetric and spectrophotometric methods of analysis using eosin y

It has been reported that eosin Y is a common dye used for determination of various pharmaceutical compounds either spectrophotometry alone or spectrophotometry and spectro-fluorimetry by the formation of a binary or ternary complex. Fig. 4 shows a schematic explanation that how the ion association complex formed with eosin Y and analyzed by spectrophotometry and spectrofluorimetry.

Table 1: Spectrofluorimetric determination of drugs using eosin Y

Drug Complex type





Range LODa LOQb Application Reference
µg/ml µg/ml µg/ml
Olanzapine Ternary 547 323 0.05-1.0 0.0018 0.006 Pharmaceutical preparations and human plasma 52
Fluphenazine Ternary 547 323 0.10-1.0 0.0012  0.004 Pharmaceutical preparations and human plasma 52
Risperidone Ternary 555 260 0.5-7 0.015 0.050 Bulk and tablets 53
Labetalol Ternary 452 317 0.5-4 0.08 0.23 Pharmaceutical preparations and urine 56
Doxepin HCl Binary 567 464 0.1-8 0.00295 0.00975 Commercial dosage forms 54
Betaxolol Binary 545 301.5 0.1-2.5 0.028 0.086 dosage forms 55
Carvedilol Binary 545 301.5 0.1-2.5 0.024 0.071 dosage forms 55
Labetalol Binary 545 301.5 0.1-2.5 0.057 0.172 dosage forms 55
Nebivolol Binary 545 301.5 0.1-2.5 0.046 0.14 dosage forms 55
Propranolol Binary 545 301.5 0.1-2.5 0.016 0.05 dosage forms 55
Labetalol Binary 432 312 1.25-30 0.24 0.73 Pharmaceutical preparations and urine 56
Chloroquine Binary 372 318 0.5–5 - - Dosage forms 57
Amodiaquine Binary 368 318 0.5-8 - - Dosage forms 57
Primaquine Binary 450 368 0.1–5 - - Dosage forms 57
Clindamycin HCl Binary 555 482 0.2-2 0.13 0.18 Pure and dosage forms 58
Almotriptan malate Binary 542.8 301.3 0.07-1.0 0.019 0.059 Pure and dosage forms 59
Rizatriptan benzoate Binary 542.8 301.3 0.20-1.0 0.041 0.125 Pure and dosage forms 59
Sumatriptan succinate Binary 542.8 301.3 0.20-1.0 0.055 0.168 Pure and dosage forms 59
Zolmitriptan Binary 542.8 301.3 0.10-1.0 0.032 0.096 Pure and dosage forms 59
Losartan Binary 546 310 0.8-8 0.203 0.617 Tablets 60
Irbesartan Binary 546 310 0.8-7 0.110 0.335 Tablets 60
Telmisartan Binary 546 310 0.9-4 0.112 0.340 Tablets 60
Valsartan Binary 546 310 1-8 0.132 0.399 Tablets 60
Amitriptyline HCl Binary 550 310 0.08-2 0.017 0.056 Pharmaceutical preparations 61
Clomipramine HCl Binary 550 310 0.06-2 0.015 0.049 Pharmaceutical preparations 61
Citalopram HBr Binary 554 259 2-26 0.121 - Dosage forms 62
Fluoxetine HCl Binary 545 301 0.2-2.4 0.066 0.036 Pharmaceutical formulations 63
Paroxetine HCl Binary 545 301 0.1-2.4 0.20 0.10 Pharmaceutical formulations 63
Ethionamide Binary 536 337 1-8 0.08 - Pharmaceutical preparations and biological fluids 64
Thioridazine Ternary 517 462 0.5-3 - - Dosage forms 65
Flupentixol Ternary 517 462 0.5-3 - - Dosage forms 65
Sunitinib malate Binary 800 350 0.08-5 0.041 0.85 Bulk and pharmaceutical preparations 66
Ebastine Binary 553 457 0.1-1.0 0.021 0.042 Pharmaceutical preparations 67
Prochlorperazinedimaleate Binary 450 318 1-10 - - Pharmaceutical preparations 68
Thiethylperazinedihydrochloride Binary 460 318 1-10 - - Pharmaceutical preparations 68
Trifloperazinedihydrochloride Binary 465 318 1-10 - - Pharmaceutical preparations 68

aLimit of detection, bLimit of quantitation.

Table 2: Spectrophotometric determination of drugs using eosin Y

Drug Complex type



Range LOD LOQ Application Reference
µg/ml µg/ml µg/ml
Tizanidine Binary 545 0.5-8 0.1 0.26 Dosage forms 72
Orphenadrine Binary 542 1-12 0.3 0.95 Dosage forms 72
Clemastine hydrogen fumarate Binary 552 1.25-11.25 0.72 2.39 Dosage forms 73
Desloratadine Binary 549 0.31-2.81 0.9 3 Dosage forms 73
Losartan potassium Binary 540 2.5-20 0.82 2.73 Dosage forms 73
Moxepril HCl Binary 540 1.25-15 0.75 2.51 Dosage forms 73
Bezafibrate Ternary 546 0.06-3 0.00915 0.0277 Pharmaceutical products 74
Amlodipine Binary 549 5-60 1.8 6.0 Bulk powder and pharmaceutical formulations 74
Nicardipine Binary 549 5-60 1.2 3.6 Bulk powder and pharmaceutical formulations 74
Terbutaline sulphate Binary 545 0.5-10 0.030 0.103 Pharmaceutical formulations 75
Tetracycline hydrochloride Binary 545 5-45 0.613 2.00 Pharmaceutical formulations 75
Erythromycin Binary 542-544 2-20 0.172 0.565 Pharmaceutical formulations and biological fluids 76
Azithromycin Binary 542-544 1-10 0.153 0.514 Pharmaceutical formulations and biological fluids 76
Clarithromycin Binary 542-544 3-30 0.281 0.906 Pharmaceutical formulations and biological fluids 76
Roxithromycin binary 542-544 2-20 0.253 0.849 Pharmaceutical formulations and biological fluids 76
Ramipril Ternary 535 20-100 - - Tablets 77
Perindopril Ternary 535 10-60 - - Tablets 77


without surfactant

533.4 56-112 1.412 - Dosage forms 78


with surfactant

558.8 20-32 0.587 - Dosage forms 78
Gatifloxacin Ternary 552 2-10 0.216 0.72 Pharmaceutical formulations 79
Moxifloxacin Ternary 549 1-8 0.184 0.613 Pharmaceutical formulations 79
Memantine HCl Binary 546 1-10 0.33 0.99 Tablets 80
Perindopril erbumine Ternary 510 10-200 0.49 1.48 Pharmaceutical preparations 81
Gliclazide Ternary 550 0.5-4 0.05 0.5 Pharmaceutical formulations and biological fluids 82
Levofloxacin Binary 547 2-8 0.1475 - Pure, pharmaceutical tablets and spiked human urine 83
Norfloxacin Binary 547 2-8 0.1402 - Pure, pharmaceutical tablets and spiked human urine 83
Ciprofloxacin Binary 547 2-8 0.1369 - Pure, pharmaceutical tablets and spiked human urine 83


Ternary 540 0-35 0.1501 0.4547 Pure and Dosage Forms  84
Orphenadrine Ternary 540 0-55 0.3109 0.9422 Pure and Dosage Forms  84
Cefixime Ternary 550 4-28 0.90 2.70 Dosage Forms 85
Glimepiride Ternary 544 5-50 1.70 5.10 Dosage Forms  86
Sparfloxacin Ternary 550 1.6-16 0.0211 0.0704 Bulk and pharmaceutical preparations 86
Minocycline Ternary 545 0-4 - - Pharmaceutical preparations 87
Meclizine Binary 540 5-25 0.76 2.29 Pure and dosage forms 88
Tolterodine tartrate Binary 545 1-10 0.10 0.31 Pharmaceutical preparations 89
Berberine sulphate Binary - - - - Tablets 90
Solifenacin succinate Ternary 545 2.5-50 0.116 0.351 Dosage forms  91
Metoclopramide HCl Binary 543 1.01-10.09 0.124 0.414 Dosage forms  92
Carbinoxamine Ternary 538 0.75-10 - - Pharmaceutical formulations 93

It was found that the binary or ternary complex formed by interaction with eosin alone or eosin and metal measured through spectrofluorimetry offers high sensitivity and selectivity compared to the spectrophotometric analysis. A list of pharmaceuticals reported in table 3 clearly states that spectrofluorimetric methods are more sensitive and have low limit of detection [94-101].

Fig. 4: Schematic diagram for ion association complexation with eosin Y and its analysis

Table 3: Comparison of spectrophotometric and spectrofluorimetric determination of drugs using eosin Y

Drug Complex type Spectrophotometry Spectrofluorimetry Application Reference



















Dothiepin HCl Binary 540 1-10 0.18 0.54 543 304 0.3-8 0.11 0.34 Pure and dosage forms 94
Hydrochlorothiazide Ternary 543 8-40 0.046 0.138 545 462 0.05-0.25 0.013 0.039 Tablets 95
Indapamide Ternary 543 8-40 0.041 0.123 545 462 0.05-0.25 0.014 0.044 Tablets 95
Xipamaide Ternary 543 8-32 0.035 0.107 545 462 0.05-0.25 0.012 0.039 Tablets 95
Ciprofloxacin Ternary 545 3-10 0.142 0.431 540 310 0.0375-0.070 0.0018 0.0055 Pure and tablets 96
Norfloxacin Ternary 545 3-10 0.138 0.419 540 310 0.025-0.050 0.0010 0.0033 Pure and tablets 96
Ropirnirole Binary 546 50-500 - - 540 350 6-150 - - Dosage forms 97
Mebeverine HCl Binary 551 1-12 0.53 1.04 540 390 0.2-3.5 0.11 0.21 Commercial Tablets 98
Doxazosin mesylate Binary 547 2-14 0.393 1.191 570 430 1-10 0.0794 0.241 Tablets 99
Astemizole Ternary 547.5 4.1-37.6 - - 545 462 0.94-7.1 - - Tablets, Suspension and capsule 100
Terfenadine Ternary 540.7 11.8-47.2 - - 545 462 0.94-7.1 - - Tablets, Suspension and capsule 100
Flunarizine HCl Ternary 547.5 2.4-19.1  - - 545 462 0.94-7.1 - - Tablets, Suspension and capsule 100
Clopidogrel Binary 545 0.5-9 0.076 0.23 560 499 0.2-6 0.0341 0.1033 Pharmaceutical preparation 101


As revealed above eosin Y is one of the important fluorescent ion pairing agent and spectrofluorimetric technique play an important role in the analysis of many pharmaceutical compounds and active current research area as a number of research articles and reviews published every year on this topic [102-108]. Spectrofluorimetry provides an extremely sensitive, selective and simple method for a variety of active pharmaceutical ingredients at a very low detection limits up to pictogram range [109]. A number of pharmaceutical compounds were also analyzed by spectrophotometry that formed a binary and/or ternary colored complex with eosin Y which proves that it is also an important technique of choice even today in pharmaceutical industries. However, the binary and ternary complex formed with eosin Y and analyzed by spectrofluorimetry offered higher sensitivity and selectivity over spectrophotometry.

Chromatographic methods such as high-performance liquid chromatography and gas chromatography were used as a valuable tool for the quantitative analysis of several pharmaceutical ingredients. However, non-chromatographic methods such as spectrofluorimetry and spectrophotometry are still extensively used in research laboratories, hospitals due to low cost, simplicity, portability and ease of operation. Both nonchromatographic methods involved in analyses utilizing the quenching nature of various fluorescent dyes and hence can be used as an alternative to chromatographic methods using eosin Y as an ion pairing agents for a variety of pharmaceutical compounds. These two methods can be recommended for routine quality control analysis of drugs where time, cost effectiveness and high specificity of analytical techniques are of great importance.


Declared none


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Eosin Y, Ion pairing agent, Spectrofluorimetry, commercial dosage forms





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International Journal of Pharmacy and Pharmaceutical Sciences
Vol 9, Issue 12, 2017 Page: 1-9

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Habibur Rahman
Department of General Studies, Jubail Industrial College, P.O. Box 10099, Jubail Industrial City 31961, Saudi Arabia
Saudi Arabia

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