Effect Of Excipients Research Articles

Low-surfactant microemulsion, a smart strategy intended for curcumin oral delivery

This study aimed to develop a low surfactant concentration curcumin-loaded microemulsion (Curc-ME) having a gastrointestinal pH resistance, intended to prospect its oral use for further curcumin release. The effect of excipients on the apparent solubility of curcumin was assessed and a pseudo ternary phase diagram was designed to produce a low-surfactant microemulsion (ME) system. Curcumin was incorporated into the ME (Curc-ME), and the system was further physicochemically and physically characterized. The entrapment efficiency (EE) was determined by UHPLC. The systems’ stability under storage, and its stability and curcumin release in simulated gastrointestinal fluids (SGIF) were evaluated. The excipients of the ME improved curcumin’s apparent solubility. Curc-ME, stabilized with 15% of surfactants, displayed spherical droplets (sized of 21.81 ± 0.20 nm), polydispersity index of 0.07 ± 0.01, viscosity of 5.33 × 10−3 ± 0.01 Pa.s, conductivity of 160 ± 3 μS cm−1, surface tension of 40.37 ± 0.48 dynes/cm and EE of 98 ± 0.73%. Thermal analyses confirmed curcumin entrapment in the core of the system. The system remained stable over 90 days under storage and under SGIF conditions. Curc-ME revealed a modified and complex kinetics release of curcumin in the SGIF. Overall, the results demonstrate that Curc-ME increased the solubility of curcumin, was produced with a remarkable low surfactant concentration, and showed stability and modified curcumin release at the gastrointestinal tract pHs. Therefore, Curc-ME revealed to be a promising candidate to be further explored as a therapeutic agent.

Enhancement of transdermal permeation of cannabinoids and their pharmacodynamic evaluation in rats

The objective of the present study was to enhance the transdermal permeation of cannabinoids: cannabidiol (CBD), cannabigerol (CBG) and tetrahydrocannabivarin (THCV) using chemical permeation enhancer approach and evaluate them for their anti-inflammatory effect in vivo in a paw edema model in rats. Cannabinoids gel formulations were developed using FDA approved inactive ingredients: lactic acid (LA), polyethylene glycol-400 (PEG-400), N-methyl-2 pyrrolidone (NMP), dimethyl sulfoxide (DMSO). In vitro skin permeation testing (IVPT) showed flux of ∼ 13.25 μg/cm2/h for CBD, ∼9.38 μg/cm2/h for CBG and ∼ 51.74 μg/cm2/h for THCV. Additionally, IVPT study showed cumulative drug permeation of 610.96 ± 88.92 μg/cm2, 432.09 ± 35.59 μg/cm2 and 2384.44 ± 42.22 μg/cm2 from CBD, CBG and THCV gel formulations respectively. Further, effect of excipients on cannabinoid permeation showed that, formulation containing lactic acid, NMP and DMSO showed significantly (p < 0.0001) enhanced flux of cannabinoids as compared to formulation without LA, NMP and DMSO. In vivo studies showed that paw edema was significantly (p < 0.0001) reduced in the groups containing CBD, CBG, THCV as compared to control and placebo formulation. In conclusion, flux of CBD, CBG and THCV was significantly enhanced using chemical permeation enhancers approach which helped in reducing rat paw edema.

Exploiting synergistic effects of brittle and plastic excipients in directly compressible formulations of sitagliptin phosphate and sitagliptin hydrochloride

Direct compression (DC) is the simplest and most economical way to produce pharmaceutical tablets. Ideally, it consists of only two steps: dry blending of a drug substance(s) with excipients followed by compressing the powder mixture into tablets. In this study, immediate-release film-coated tablets containing either Sitagliptin phosphate or Sitagliptin hydrochloride were developed using DC technique. After establishing the optimum ratio of ductile and brittle excipients, five formulations were compressed into tablets using a rotary press and finally film coated. Both powders and tablets were examined by standard pharmacopoeial methods. It has been shown that the simultaneous use of excipients with different physical properties, i.e. ductile microcrystalline cellulose and brittle anhydrous dibasic calcium phosphate, produces a synergistic effect, allowing preparation of Sitagliptin DC tablets with good mechanical strength (tensile strength over 2 N/mm2), rapid disintegration (shorter than 2 min), and fast release of the drug substance (85% of the drug is dissolved within 15 min). It was found that the type of calcium phosphate excipient used had a large effect on the properties of the sitagliptin tablets. All formulations developed showed good chemical stability, even when stored under stress conditions (50 °C/80% RH).

Proliposome: A Novel Solution for the Stability of Liposomes - A Review

Proliposome are phospholipid-based vesicular drug delivery systems that have specialized applications in drug delivery via various routes of administration. They are widely researched as potential carriers for improving bioavailability through oral administration of drugs with low bioavailability and are composed of the drug, phospholipid, and a water-soluble carrier or porous powder. The technology is based on the inherent ability of hydrated membrane lipids to form liposomal vesicles when exposed to water. It is specifically designed for molecular dispersion and delivery of hydrophilic and hydrophobic drugs to achieve good bioavailability, local, systemic effects, and site-specific drug delivery strategies. By utilizing phospholipids and various carriers, these vesicular systems play critical roles in improving bioavailability and solubility. An in-depth understanding of the physical and biological behavior of Proliposome is required for designing an effective delivery system that will increase drug availability at the anticipated site. Proliposome provide an opportunity to improve drug therapeutic action by modifying drug uptake mechanisms. The Proliposome approach was developed as a simple, repeatable, and dependable manufacturing technique for large-scale production of liposome dispersions. The present review discusses the use of Proliposome to improve the oral bioavailability of poorly water-soluble drugs, components for the formulation, effects of excipients, techniques for preparation, evaluation of Proliposome, and other key issues related to various routes of administration. Proliposome formulation is an alternative, novel solution for liposome stability.

Tavaborole microemulsion: New strategy for the targeted treatment of onychomycosis

The targeted treatment of onychomycosis becomes a major concern nowadays for onychologist considering the limited permeability of the drug formulation at the nail site due to the number of factors such as complex barrier of keratin structure inside the nail layer, drug-keratin binding properties, as well as lack of availability of promising drug delivery system. In the present study, tavaborole-loaded novel microemulsion and its gel formulation was developed, optimized, and evaluated for the targeted treatment of onychomycosis. The microemulsion formulation was designed and developed using a 32 factorial experimental design approach. The optimized microemulsion formulation consisting of tavaborole (2.5%w/w), glyceryl caprylate/caprate (7.8%w/w), polyethylene glycol-8 caprylate/capric glycerides (21.45%w/w), diethylene glycol monoethyl ether (21.45%w/w) and demineralized water (46.80%w/w) was converted to gel using carbopol® 934P (0.5%w/w). In the ex-vivo bovine hoof membrane model permeation study, the optimized microemulsion formulation exhibited higher drug permeation (116.21 ± 9.75 μg/cm2) and followed the first-order release kinetics mechanism. The in-vitro nail clipping study demonstrated enhanced penetration of tavaborole (0.872 ± 0.019 μg/mg) from optimized microemulsion formulation. It also exhibited improved antifungal activity against dermatophytes species such as Trichophyton rubrum (2.56 ± 0.086 cm), Trichophyton mentagrophytes (3.13 ± 0.097 cm), and Candida albicans (3.63 ± 0.103 cm). The microemulsion formulation did not reveal any toxic and detrimental effects of excipients on nail cells in VERO cell lines cytotoxicity study. Thus, tavaborole loaded microemulsion can be considered as a potential formulation for topical onychomycosis therapy.

Lipid based Vehicles and Lipid-based Excipients in Drug delivery

In recent years, there has been increasing interest in the use of formulations containing lipid-based excipients that comprise combinations of synthetic or semisynthetic lipids with surfactants, co-surfactants or co-solvents. This review is generally focussed on lipid-based excipients in pharmaceutical formulations which improves the oral bioavailability of poorly water-soluble drugs. Lipid-based formulations can reduce the limitations of slow and incomplete dissolution of poorly water-soluble drugs, and facilitate the formation of solubilised phases from which absorption may occur. The improvement of bio-availability of drugs is one of the greatest challenges in drug formulations. This review discusses novel lipids like Compritol 888 ATO, Dynasan 114, Glyceryl monooleate (GMO), Maisine CC and Precirol ATO 5 focussing on how these can be employed for devising efficient drug delivery systems and also the in vivo effect and fate of lipid excipients.

Effect of functional excipients on the dissolution and membrane permeation of furosemide formulated into multiple-unit pellet system (MUPS) tablets

The effect of functional excipients (i.e. chitosan, sodium lauryl sulphate, NaHCO3, and CaCO3) formulated in multiple-unit pellet system (MUPS) tablets has been investigated on the dissolution and permeability of furosemide, a BCS class IV compound. Spherical beads were produced and compressed into MUPS tablets. MUPS tablet formulations were evaluated for hardness, disintegration, mass variation, friability, and dissolution (pH 1.2, pH 4.6, and pH 7.4). Ex vivo permeability studies were conducted across excised pig tissues (pyloric antrum and duodenal region) on selected experimental MUPS tablet formulations. Histological analysis was conducted on the tissues after exposure to selected experimental MUPS tablet formulations. Dissolution results in the 0.1 M HCl (pH 1.2) showed the highest effect of the excipients on furosemide release. Dissolution parameters showed increased dissolution of furosemide for the MUPS tablet formulations containing functional excipients: a 4.5–10-fold increase in the AUC values, the %max showed a 60–70% increase and up to a 19-fold increase in DRi was seen. Permeability results revealed a 2.5-fold higher cumulative percentage transport for selected formulations. The results proved that functional excipients incorporated into beads, compressed into MUPS tablet formulations increased furosemide release as well as permeation across excised intestinal tissues.

Prospects for the development of solid dispersed systems of antibiotics (scoping review)

Introduction. Currently, there is a large number of antibacterial medications for the treatment of infectious diseases on the pharmaceutical market. Fluoroquinolones, being an important group among these medications, have a wide spectrum of action and are active against multiresistant bacteria, one of which is ofloxacin. Ofloxacin is characterized by low solubility and belongs to the second class according to the biopharmaceutical classification of medications, so it is advisable to use the method of introducing it into solid carriers to increase bioavailability. Purpose of the article is to describe methods for obtaining new dosage forms of ofloxacin with increased bioavailability. Materials and methods : Having analyzed the literature on the topic, the authors presented a brief description of the methods and techniques for the manufacture of solid dispersions with this active substance. Results and conclusion : The effect of other excipients, such as surfactants, on the release of the medication from the formulation has been described. The physicochemical and biopharmaceutical methods that can be used to establish the quality of the newly developed dosage form of ofloxacin are reflected. Using the methods described in the article, it is possible to create a new dosage form of ofloxacin with improved biopharmaceutical performance in relation to existing medications on the market. This method will allow the creation of a prolonged drug with fewer side effects and more profitable in economic terms.

Particle-Assisted Dermal Penetration-A Simple Formulation Strategy to Foster the Dermal Penetration Efficacy.

(1) Background: The study systematically investigated the influence of dispersed particles within a topical formulation on the dermal penetration efficacy of active compounds that are dissolved in the water phase of this formulation. The aim was to prove or disprove if particle-assisted dermal penetration can be used for improved dermal drug delivery. (2) Methods: Fluorescein was used as a surrogate for a hydrophilic active ingredient (AI). It was dissolved in the water phase of different formulations with and without particles. Two different types of particles (titanium dioxide and nanostructured lipid carriers (NLC)) were used. The influence of particle size and number of particles and the influence of skin hydrating excipients was also investigated. (3) Results demonstrate that the addition of particles can strongly increase the dermal penetration efficacy of AI. The effect depends on the size of the particles and the number of particles in the formulation, where smaller sizes and higher numbers resulted in higher penetration parameters. Formulations with NLC that contained 20% w/w or 40% w/w particles resulted in an about 2-fold higher amount of penetrated AI and increased the penetration depth about 2.5-fold. The penetration-enhancing effect was highly significant (p < 0.001) and allowed for an efficient delivery of the AI in the viable dermis. In contrast, the penetration-enhancing effect of excipients that increase the skin hydration was found to be very limited and not significant (≤5%, p > 0.05). (4) Conclusions: Based on the results, it can be concluded that particle-assisted dermal penetration can be considered to be a simple but highly efficient and industrially feasible formulation principle for improved and tailor-made dermal drug delivery of active compounds.

A Critical Overview of the Biological Effects of Excipients (Part I): Impact on Gastrointestinal Absorption.

Traditionally, excipients have been considered in drug development from the perspective of their influence on drug solubility, manufacturability, and ability to control in vitro and in vivo drug release. These effects have been largely evaluated through studies involving in vitro dissolution methods. However, there is a growing awareness that what had previously been considered biologically inert excipients can exert numerous in vivo effects. This includes the potential to change gastrointestinal (GI) transit time, enterocyte passive transcellular or paracellular permeability, active transport activity, or presystemic drug metabolism. In this critical overview of the biological effects of excipients (Part I), we provide a summary of select published studies that explore these various in vivo factors. We also include a table that points readers to published reviews that list a range of excipients known to have biological activity. A subsequent discussion on in vitro, in vivo, and in silico methods that can be used to explore these excipient effects is provided in a separate (Part 2) continuation of this critical overview.

A Critical Overview of the Biological Effects of Excipients (Part II): Scientific Considerations and Tools for Oral Product Development.

It is now recognized that a number of excipients previously considered to be "inert" have the capacity to alter drug oral bioavailability through a range of in vivo effects. The various mechanisms through which an excipient can affect in vivo gastrointestinal physiology and drug absorption characteristics were explored in "A Critical Overview of The Biological Effects of Excipients (Part I): Impact on Gastrointestinal Absorption." The next critical issue that needs to be discussed is how these biological effects are evaluated. Therefore, in Part 2 of this critical overview, the in vitro, in vivo, and in silico methods for evaluating excipient effects are considered. Examples are provided to illustrate how such studies employing these various procedures have been used to promote formulation understanding and optimization. Finally, a discussion of how the Center for Drug Evaluation and Research applies these tools to support biowaivers is provided.

Development of a Spectroscopic Method for the Determination of Oxcarbazepine Using Green Synthesized Silver Nanoparticles

The present work describes the development of efficient spectroscopy-based analytical method for the determination of oxcarbazepine (OXC) using silver nanoparticles. The proposed method is simple, accurate, and reproducible. It employs green synthesized silver nanoparticles for the detection and estimation of OXC. In the estimation method, aliquots of OXC are made to react with silver nanoparticles in an ammoniacal medium to produce a yellow color that can be measured spectrophotometrically. A calibration curve was plotted that showed a linear response in absorbance with an increase in the concentration of the drug. The method is then validated for precision and accuracy according to ICH guidelines. Different parameters like optimized reagent concentrations, sequence of addition of reagents, the effects of temperature, pH, and waiting period before spectroscopic analysis are performed. The method was also tested for intra-day and inter-day precision and the effect of excipients to assess its ruggedness.

A Comprehensive Insight on Self Emulsifying Drug Delivery Systems.

The oral route is a highly recommended route for the delivery of a drug. But most lipophilic drugs are difficult to deliver via this route due to their low aqueous solubility. Selfemulsifying drug delivery systems (SEDDS) have emerged as a potential approach of increasing dissolution of a hydrophobic drug due to spontaneous dispersion in micron or nano sized globules in the GI tract under mild agitation. The main motive of this review article is to describe the mechanisms, advantages, disadvantages, factors affecting, effects of excipients, possible mechanisms of enhancing bioavailability, and evaluation of self-emulsifying drug delivery systems. Self emulsifying systems incorporate the hydrophobic drug inside the oil globules, and a monolayer is formed by surfactants to provide the low interfacial tension, which leads to improvement in the dissolution rate of hydrophobic drugs. The globule size of self-emulsifying systems depends upon the type and ratio of excipients in which they are used. The ternary phase diagram is constructed to find out the range of concentration of excipients used. This review article also presents recent and updated patents on self-emulsifying drug delivery systems. Self-emulsifying systems have the ability to enhance the oral bioavailability and solubility of lipophilic drugs. This technique offers further advantages such as bypassing the first pass metabolism via absorption of drugs through the lymphatic system, easy manufacturing, reducing enzymatic hydrolysis, inter and intra subject variability, and food effects.

A Physiologically Based Pharmacokinetic Model for Studying the Biowaiver Risk of Biopharmaceutics Classification System Class I Drugs With Rapid Elimination: Dexketoprofen Trometamol Case Study.

Biowaiver based on the biopharmaceutics classification system (BCS) has been widely used in the global market for the approval of new generic drug products to avoid unnecessary in vivo bioequivalence (BE) studies. However, it is reported that three out of four formulations of dexketoprofen trometamol (DEX) tablets (BCS class I drug) failed the first BE study. The aim of this study was to determine whether the current biowaiver standard is reasonable for DEX. Thus, we successfully established a physiologically based pharmacokinetic (PBPK) model for DEX and examined the effects of dissolution, permeability, and gastric emptying time on DEX absorption under BCS-based biowaiver conditions using sensitivity analyses. Parameter sensitivity analysis showed that the dissolution rate in pH 1.2 media, permeability, and liquid gastric emptying time were sensitive parameters of Cmax. Therefore, gastric emptying variation was introduced into the PBPK model, and virtual BE studys were conducted on original research formulation and the formulation of the boundary dissolution rate (f2 = 50) prescribed by the biowaiver guideline. The virtual BE results showed dissolution rate changes within the biowaiver range will not cause high non-BE ratio, indicate waive of DEX generic drugs would not lead the risk of Cmax when generic products satisfy the requirements of biowaiver guideline. However, the effect of excipients on gastric emptying as a sensitive factor needs to be further studied when the rapid elimination of BCS class I drug is biowaived.

Development of a methodological approach to determine regression equations in the study of the technology for manufacturing tablets based on quercetin

When developing the technology of tablets and tablet masses one of the tasks is to determine the amounts of excipients required to obtain pharmaco-technological quality indicators that meet the requirements of the State Pharmacopoeiaof Ukraine (SPhU). Aim. To develop an algorithm for determining the type of three-factor mathematical models with dependent variables. Materials and methods. The study object was experimental observations of the quantitative effect of excipients in the tablet composition based on a solid dispersion of quercetin on the pharmacopeial characteristics of this dosage form, in particular on its flowability. The experimental data were processed by the planned experiment using Mathcad 15 and MS Excel software according to the algorithm proposed. Results and discussion. It has been found that the identification of mathematical models in pharmaceutical studies with three dependent factors, which total value is determined by the quantitative composition of the dosage formand fixed at a certain level, is difficult to perform due to the difficulty of interpreting the multiple regression parameters as characteristics of factors in isolation through their correlability. It has been proven that the replacement of variablesleads to the determination of a mathematical model that does not reveal the mechanism of the factors’ action and is a static description of their overall impact on the indicator studied. Conclusions. As a result of the research conducted, regression equations were found to determine the effect of the amount of these excipients on the tablet flowability. It has been found that the most influential role in determining the target in the factor space studied is played by the interaction of factors. The algorithm for determining the mathematical description of the dependence with three variables has been proposed. Based on the fact that the research is conditioned by strict conditions in the quantitative composition, the chosen mathematical model of the dependence of the quadratic equation with two factors, for which there are limitations, has no correlation. The model determined is characterized by the possibility of providing the graphical interpretation and simplification of analysis and can be used for forecasting and optimization.

Adaptation of the Kirkstall QV600 LLI Microfluidics System for the Study of Gastrointestinal Absorption by Mass Spectrometry Imaging and LC-MS/MS.

Absorption studies on oral drugs can be difficult due to the challenge of replicating the complex structure and environment of the GI tract. Drug absorption studies can be conducted using in vivo and ex vivo animal tissue or animal-free techniques. These studies typically involve the use of Caco-2 cells. However, Caco-2 cells do not incorporate all the cell types found in intestinal tissue and lack P450 metabolizing enzymes. The QV600 LLI system is a microfluidics system designed for use with cell culture. Here, it has been adapted to house appropriate sections of ex vivo porcine tissue to act as a system that models the duodenum section of the small intestine. A pH regulated solution of Atorvastatin was flowed over the apical layer of the GI tissue and a nutrient solution flowed over the basal layer of the tissue to maintain tissue viability. The tissue samples were snap-frozen, cryosectioned, and imaged using MALDI Mass Spectrometry Imaging (MSI). A proof-of-concept study on the effect of excipients on absorption was conducted. Different concentrations of the solubilizing agent were added to the donor circuit of the QV600 LLI. The amount of Atorvastatin in the acceptor circuit was determined to study the effect of the excipient on the amount of drug that had permeated through the tissue. Using these data, Papp, pig values were calculated and compared with the literature.

Study on the Effect of Polymer Excipients on the Dispersibility, Interaction, Solubility, and Scavenging Reactive Oxygen Species of Myricetin Solid Dispersion: Experiment and Molecular Simulation.

Although the preparation of amorphous solid dispersions can improve the solubility of crystalline drugs, there is still a lack of guidance on the micromechanism in the screening and evaluation of polymer excipients. In this study, a particular method of experimental characterization combined with molecular simulation was attempted on solubilization of myricetin (MYR) by solid dispersion. According to the analysis of the dispersibility and hydrogen-bond interaction, the effectiveness of the solid dispersion and the predicted sequence of poly(vinyl pyrrolidone) (PVP) > hypromellose (HPMC) > poly(ethylene glycol) (PEG) as the polymer excipient were verified. Through the dissolution, cell viability, and reactive oxygen species (ROS)-level detection, the reliability of simulation and micromechanism analysis was further confirmed. This work not only provided the theoretical guidance and screening basis for the miscibility of solid dispersions from the microscopic level but also served as a reference for the modification of new drugs.

Optimization of Spray-Drying Process Parameters to Study Anti-Sticking Effect of Hydroxypropyl Methyl Cellulose-VLV on Corni fructus Extracts.

To prevent the sticking of Corni fructus extract (CFE) during spray drying, the anti-sticking effects of different excipients were compared. Hydroxypropyl methylcellulose (HPMC)-VLV showed a higher powder yield at a lower dosage (8% of total solids), and a lower solution viscosity, compared with HPMC-E5. Therefore, HPMC-VLV is a more effective excipient for reducing CFE sticking during spray drying. The spray-drying process parameters were optimized by central composite rotatable design/response surface methodology, and spray drying was conducted under the following conditions: Inlet air temperature, 126 °C; atomization pressure, 1.05 bar; pump speed, 7.7 mL/min. Scanning electron microscopy showed that the powder comprised shrunken spherical particles with particle sizes in the range of 2-30 μm. Analysis of dynamic surface tension and chemical elements on the powder surface showed that HPMC-VLV rapidly moved to the droplet surface owing to its surface activity. HPMC covered the droplet surface and reduced surface tension, achieving an anti-sticking effect. In conclusion, HPMC-VLV at a solid content of 8% significantly improved the spray drying and reduced sticking of CFE. The spray-drying process parameters were nonlinearly related to the dry product yield. Graphical Abstract.

Relationship between sensorial and physical characteristics of topical creams: A comparative study on effects of excipients

Rising consumer demands for safer, more natural, and sustainable topical products have led to increased interest in finding alternative excipients, while retaining functionality and cosmetic appeal. Particle-stabilized Pickering creams have emerged as possible alternatives to replace traditional surfactant-stabilized creams and are thus one of the focuses in this study. The aim of this paper was to study relationships between sensorial characteristics and physical properties to understand how different excipients affect these aspects, comparing one starch particle–stabilized and three surfactant-stabilized formulations. A human panel was used to evaluate sensorial perception, while physical properties were deduced by rheology and tactile friction, together with in vivo and ex vivo skin hydration measurements.The results show that sensorial attributes related to the application phase can be predicted with rheology, while afterfeel attributes can be predicted with tactile friction studies. Differences in rheological and sensory properties among surfactant-based creams could mainly be attributed to the type of emollients used, presence of thickeners and surfactant composition. Differences between surfactant-based creams and a Pickering cream were more evident in relation to the afterfeel perception. Presence of starch particles in the residual film on skin results in high tactile friction and low perception of residual coating, stickiness, greasiness, and slipperiness in sensorial afterfeel.

Micellar-Enhanced Spectrofluorimetric Method for Quantification of Diclofenac Potassium in Pure Form, in Pharmaceutical Preparations and Human Plasma

Abstract A rapid, simple and economical spectrofluorimetric method for the determination of diclofenac potassium in pure form, in pharmaceutical preparations and in human plasma has been developed. The method is based on the enhancement of the fluorescence signal of diclofenac potassium by the addition of sodium dodecyl sulphate in McIvaine buffer with a pH of 5. Different experimental conditions such as buffer type, pH, type and concentration of surfactants were investigated. The fluorescence intensity of the solution was recorded at 361 nm after excitation at 243 nm. The method shows linearity in the concentration range of 0.2 μg mL–1–10 μg mL–1 with a good correlation coefficient of 0.997. The relative standard deviation value was 3.62 (n = 7). The limit of detection and limit of quantification were calculated to be 2.84 × 10–3 μg mL–1 and 9.47 × 10–3 μg mL-1, respectively. The effect of excipients and co-administrated drugs was investigated and no interference was observed. The method was successfully applied for the determination of diclofenac potassium in pure form, in pharmaceutical products and in human plasma. The percentage recoveries obtained ranged from 100.25% to 102.16% for pure form and 97.50% to 102.00% for pharmaceutical products and from 98.50% to 101.67% for human plasma.