Analysis of omarigliptin forced degradation products by ultra-fast liquid chromatography, mass spectrometry, and in vitro toxicity assay.

Omarigliptin (OMG) is an antidiabetic drug indicated for the treatment of type 2 diabetes mellitus. Forced degradation studies are practical experiments to evaluate the stability of drugs and to establish degradation profiles. Herein, we present the investigation of the degradation products (DPs) of OMG formed under various stress conditions. OMG was subjected to hydrolytic (alkaline and acidic), oxidative, thermal, and photolytic forced degradation. A stability-indicating ultra-fast liquid chromatography method was applied to separate and quantify OMG and its DPs. Five DPs were adequately separated and detected in less than 6 min, while other published methods detected four DPs. MS was applied to identify and obtain information on the structural elucidation of the DPs. Three m/z DPs confirmed previously published research, and two novel DPs were described in this paper. The toxicity of OMG and its DPs were investigated for the first time using in vitro cytotoxicity assays, and the sample under oxidative conditions presented significant cytotoxicity. Based on the results from forced degradation studies, OMG was found to be labile to hydrolysis, oxidation, photolytic, and thermal stress conditions. The results of this study contribute to the quality control and stability profile of OMG.

Development and validation of capillary zone electrophoresis and high-performance liquid chromatography methods for the determination of oral anticoagulant edoxaban in pharmaceutical tablets.

The incidence of thrombotic complications in SARS-CoV-2 infections has become a global concern; thus, anticoagulants are an integral part of the treatment. Edoxaban (EDX) is an oral anticoagulant suitable for pharmacologic thromboprophylaxis. Herein, two novel analytical methods for EDX determination in tablets are developed and validated using capillary zone electrophoresis (CZE) and high-performance liquid chromatography (HPLC). Operating conditions such as the electrolyte's concentration and pH value, injection time, volume, and the capillary temperature, were optimized. The methods were successfully validated by establishing the linearity, intra- and inter-day precisions (relative standard deviation [%]), accuracy, and robustness. Adequate separation of excipients and degradation products of EDX generated by stress degradation conditions demonstrated the stability-indicating capability of the methods. The analytical procedures were linear in the range of 25-125 µg/ml (r > 0.999), with the limits of detection and quantification of 3.26 and 10.87 µg/ml for CZE and 0.740 and 2.78 µg/ml for HPLC. Although both methodologies are suitable for determining EDX in tablets, CZE provides a greener alternative due to low-cost analysis using less organic solvents and minimizing waste generation.

Development, Quality by Design-Based Optimization, and Stability Assessment of Oral Liquid Formulations Containing Baclofen for Hospital Use.

The absence of oral liquid pharmaceutical forms appropriate for use in pediatric and adult patients with difficulty swallowing is a public health problem, especially in the hospital context. Baclofen is a muscle relaxant of choice for treating spasticity, generally marketed only in tablet form, highlighting the need for liquid formulations to facilitate dose adjustment, administration, and swallowing. The present study aimed to develop oral liquid formulations containing baclofen, optimize them through the quality by design approach, and evaluate their physicochemical and microbiological stability. Preformulation and preliminary stability studies were carried out for the development of formulations. Experimental screening and optimization designs resulted in eleven experiments for each step that were evaluated for 28 days. A stability-indicating method by high-performance liquid chromatography presented linearity, low limits of detection and quantification, precision, accuracy, and robustness. The experimental design led to two optimized formulations containing baclofen, glycerin, potassium sorbate, citric acid, ultrapure water, flavor, and sucrose syrup or sodium carboxymethylcellulose solution as a vehicle, the last one with sucralose as a sweetener. The formulations were placed in amber glass flasks and subjected to a physicochemical and microbiological stability study. Both formulations showed physicochemical and microbiological stability when stored at room temperature and refrigerated for 84 days. The results of this study may serve as a reference in the preparation of liquid oral formulations containing baclofen in the hospital routine and collaborate with the safety and adherence to the treatment of adult and pediatric patients.

Microbial transformation of ambrisentan to its glycosides by Cunninghamella elegans.

The purpose of this paper is to describe the glycosylation of ambrisentan (AMB) by cultures of Cunninghamella elegans ATCC 9245. AMB is an endothelin receptor antagonist, which is used to treat pulmonary arterial hypertension. Filamentous fungi are morphologically complex and may exhibit different forms depending on the species and the nature of the culture medium. A biotransformation study was conducted to investigate the ability of C. elegans to metabolize AMB. Parameters were optimized by testing on different culture media and concentrations, pH, drug concentration, static and shaking conditions. Ambrisentan's metabolite, obtained after 240 h of incubation as a result of glycosylation pathway, was separated by HPLC and determined by high-resolution mass spectrometry. The method showed linearity over 300-1000 µg mL-1 (r = 0.998). Accuracy, precision, robustness and stability studies agree with international guidelines. Results are consistent in accordance with the principles of green chemistry as the experimental conditions had a low environmental impact, and used little solvent.

In vitro toxicity assessment of rivaroxaban degradation products and kinetic evaluation to decay process.

Degradation kinetics of oral anticoagulant rivaroxaban (RIV) was assessed in acid and alkaline media and while exposed to UVC radiation. Among all stress conditions tested, kinetic degradation process was better described by a zero-order model. A stability indicating method was validated for the analysis of the anticoagulant RIV in tablets by high-performance liquid chromatography. Robustness was evaluated with a two-level Plackett-Burman experimental design. The effect of acute exposition of the human hepatoblastoma HepG2 cell line to RIV stressed samples (100 and 500 µM) was assessed through in vitro toxicity tests. MTT reduction, neutral red uptake, mitochondrial membrane potential, and low molecular weight DNA diffusion assays were employed for cytotoxicity evaluation (5×104 cells/well). The genotoxic potential was assessed by comet assay (2×104 cells/well). Acute toxicity to HepG2 cells was assessed after 24 h incubation with sample solutions, for each test. A direct relationship between the increased amount of alkaline degradation products and higher cytotoxic potential was found. Results obtained by viability assay investigations support the concerns on risks associated with acute toxicity and genotoxicity of pharmaceutical samples containing degradation products as impurities.

In vitro dissolution method fitted to in vivo absorption profile of rivaroxaban immediate-release tablets applying in silico data.

OBJECTIVE: This study aimed to develop and validate an in vitro dissolution method based on in silico-in vivo data to determine whether an in vitro-in vivo relationship could be established for rivaroxaban in immediate-release tablets. SIGNIFICANCE: Oral drugs with high permeability but poorly soluble in aqueous media, such as the anticoagulant rivaroxaban, have a major potential to reach a high level of in vitro-in vivo relationship. Currently, there is no study on scientific literature approaching the development of RIV dissolution profile based on its in vivo performance. METHODS AND RESULTS: Drug plasma concentration values were modeled using computer simulation with adjustment of pharmacokinetic properties. Those values were converted into drug fractions absorbed by the Wagner-Nelson deconvolution approach. Gradual and continuous dissolution of RIV tablets was obtained with a 30 rpm basket on 50 mM sodium acetate +0.2% SDS, pH 6.5 medium. Dissolution was conducted for up to 180 min. The fraction absorbed was plotted against the drug fraction dissolved, and a linear point-to-point regression (R2 = 0.9961) obtained. CONCLUSION: The in vitro dissolution method designed promoted a more convenient dissolution profile of RIV tablets, whereas it suggests a better relationship with in vivo performance.

Anti-inflammatory effect of geranium nanoemulsion macrophages induced with soluble protein of Candida albicans.

Pelargonium graveolens is a member of the Geraniaceae family and has been used in folk medicine in many countries because of its anti-inflammatory activity. No studies have yet been reported to evaluate the anti-inflammatory activity of a nanoemulsion containing geranium oil (GO) model in macrophages. In this study the anti-inflammatory effect of Geranium nanoemulsion (NEG) macrophages induced with soluble proteins of Candida albicans was investigated. GO presented citronellol (17.74%) and geraniol (14.43%) as main constituents. The characterization in NEG was demonstrated, showing the particle size of 164 ± 3.5 nm, PDI of 0.12 ± 0.006 and zeta potential -10 mV ± 1.7. The MIC obtained for NEG and GO were 3.64 µg ml-1 and 1.82 µg ml-1, respectively. The viability of the macrophages treated with NEG and GO concentrations (1/2 x, 1x and 2x MIC) was evaluated. There was a significant reduction of viability and the MTT assay was not confirmed after the LDH assay. Anti-inflammatory activity was evaluated by determining nitric oxide (NO), cytokines (interleukin IL-1, IL-6 and IL-10), tumor necrosis factor-α (TNF) and the expression levels gene of interleukin (IL-2), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). The apoptosis inhibition capacity was assessed by determination of INFγ, caspase 3 and caspase 8. The results indicated that there was a significant increase of NO in the levels after treatment with NEG and significantly reduced levels after treatment with GO. The cytokines (IL-1, IL-6, IL-10, and TNF) were evaluated and NEG (½ x, 1x MIC) decreased IL-1 levels by 1.25-1.37 times, respectively. The NEG did not decrease IL-6 levels and a significant increase was observed for IL-10. GO significantly decreased IL-6 and IL-10 levels. There was a significant decrease in IL-2 and COX-2 levels and increased levels of iNOs. The levels of IFNγ and caspase-3 after treatment with NEG decreased indicating an anti-inflammatory effect and can inhibit apoptosis. Finally, the levels of caspase-8 do not change. Thus, pretreatment with NEG induced an anti-inflammatory effect against soluble proteins of C. albicans model macrophages.

Anti-Candida activity assessment of Pelargonium graveolens oil free and nanoemulsion in biofilm formation in hospital medical supplies.

Infections due to microbial biofilm formation on the surface of catheters and other medical devices are constantly reported as a major cause of morbidity and mortality in patients admitted to hospitals. Furthermore, sessile cells are more resistant to phagocytosis and most antimicrobial, which complicates the treatment of such infections. Researches aimed at new antimicrobial originating mainly from plants have increased in recent years and the development of new strategies for their release is critical in combating the formation of biofilms. Geranium oil (GO) has proven antimicrobial activity. Because of this, the aim of this study was to develop nanoemulsions containing this oil (NEG) and evaluate its activity after the biofilm formation of Candida albicans, Candida tropicalis, Candida glabrata, and Candida krusei in hospital medical supplies. For quantification of the biofilm, crystal violet, total protein, and ATP-bioluminescence assays were used. The results revealed that GO and NEG showed lower MIC for C. albicans and C. tropicalis. The biofilms formed by different species of Candida on the surfaces of polyethylene and polyurethane were quantified. GO and NEG significantly inhibited the formation of biofilms in all species tested on the surfaces of polyethylene. However, NEG antibiofilm has had better activity than GO for C. albicans, C. tropicalis and C. glabrata, according to the surface potential analysis by atomic force microscopy (AFM). The analysis of the biofilm formation on the polyethylene surface by ATP-bioluminescence and CFU showed similar results. In both methods the formation of biofilm in the catheter occurred in greater quantity for C. albicans and C. tropicalis. GO did not significantly inhibit the formation of biofilms only in C. krusei, although NEG significantly increased this activity GO in all species tested when compared to the control training biofilm. The following study shows that the development of NEG may become an effective alternative to reduce the adhesion of microorganisms and prevent infections resulting from the use of some hospital medical materials.

Structural elucidation of gemifloxacin mesylate degradation product.

Gemifloxacin mesylate (GFM), chemically (R,S)-7-[(4Z)-3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl]-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate, is a synthetic broad-spectrum antibacterial agent. Although many papers have been published in the literature describing the stability of fluorquinolones, little is known about the degradation products of GFM. Forced degradation studies of GFM were performed using radiation (UV-A), acid (1 mol L(-1) HCl) and alkaline conditions (0.2 mol L(-1) NaOH). The main degradation product, formed under alkaline conditions, was isolated using semi-preparative LC and structurally elucidated by nuclear magnetic resonance (proton - (1) H; carbon - (13) C; correlate spectroscopy - COSY; heteronuclear single quantum coherence - HSQC; heteronuclear multiple-bond correlation - HMBC; spectroscopy - infrared, atomic emission and mass spectrometry techniques). The degradation product isolated was characterized as sodium 7-amino-1-pyrrolidinyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylate, which was formed by loss of the 3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl ring and formation of the sodium carboxylate. The structural characterization of the degradation product was very important to understand the degradation mechanism of the GFM under alkaline conditions. In addition, the results highlight the importance of appropriate protection against hydrolysis and UV radiation during the drug-development process, storage, handling and quality control.

Gemifloxacin mesylate (GFM): dissolution test based on in vivo data.

Gemifloxacin mesylate (GFM) is a synthetic, broad-spectrum, fluoroquinolone antibacterial agent. It is different from other class members because it achieves adequate plasma concentrations to inhibit both topoisomerase IV and gyrase. The aim of this study was to develop and validate a dissolution test for GFM in coated tablets, using a simulated absorption profile based on in vivo data obtained from the literature. The fraction and percentage of the dose absorbed were calculated using model-dependent Loo-Riegelman approach for two compartments. The best in vitro dissolution profile was obtained using 900 mL of pH 6.0 phosphate buffer as a dissolution medium at 37 °C ± 0.5 °C and paddles at 50 rpm. The in vitro dissolution samples were analyzed using a liquid chromatography method, and the validation was performed according to USP 34 (2011). The method showed specificity, precision, accuracy, robustness and linearity. Under these conditions, a level-A in vitro-in vivo correlation was suggested (r = 0.9926). The prediction errors were calculated to determine the validity and accuracy of the suggested correlation. The dissolution test can be used to evaluate the dissolution profile of GFM-coated tablets and minimize the number of bioavailability studies as part of new formulation development.

Highly selective colorimetric method to determine gemifloxacin mesylate in the presence of a synthetic impurity.

A simple visible spectrophotometric method was developed for the determination of gemifloxacin mesylate (GFM) in tablets. The method was based on the formation of a yellow ion-pair complex between the basic nitrogen of the drug and the sulfonphthalein acid dye in phthalate buffer. The method was validated by the study of its specificity, linearity, precision, accuracy, and robustness. The assay was compared with an LC and a microbiological method, and the analysis of variance showed no significant difference between the methods (P>0.05). The results demonstrated that the visible spectrophotometric method is suitable for determination of GFM in tablets, even in the presence of a synthetic impurity.

Losartan potassium liquid formulation for paediatric hospital use: development and stability evaluation.

OBJECTIVES: This study aimed to develop a liquid oral formulation containing losartan potassium, an angiotensin II receptor antagonist drug used for its antihypertensive activity, and to perform a preliminary stability assessment under different temperatures and packages to ensure paediatric therapeutic adherence and facilitate the hospital routine. METHODS: A syrup containing losartan potassium (1.0 and 2.5 mg/mL) (excipients: potassium sorbate, sucrose (85%), water, citric acid and raspberry flavouring) was prepared. The packaging was carried out in amber polyethylene terephthalate (PET) and amber glass bottles (in triplicate) under the following conditions: (a) room temperature (15-30°C); (b) refrigeration (2-8°C); and (c) oven temperature (40°C) for 28 days. An analytical method by high performance liquid chromatography using a reverse-phase column was also developed and validated for quantitative determination of the drug in the formulations. RESULTS: The analytical method showed satisfactory linearity, detection and quantification limits, precision, accuracy and robustness. Samples at room temperature maintained content values between 90% and 110% for 7 days, while those stored under refrigeration maintained a homogeneous appearance and content between 90% and 110% for a period of 21 days. Values of pH stayed in a narrow range. Viscosity results were between 40.1 and 49.2 centipoise (cp) for glass bottles and 42.4 and 54.7 cp for PET bottles. CONCLUSIONS: A simple and economical losartan potassium liquid formulation was produced and was shown to be stable under refrigeration for 21 days in both PET and glass packages.

Biological safety studies of gemifloxacin mesylate and related substances.

PURPOSE: The aim of this study was to evaluate the cytotoxic, phototoxic, genotoxic and photogenotoxic potential of gemifloxacin mesylate (GFM), its main synthetic impurity (SI) and one isolated and structurally elucidated degradation product (DP). METHODS: The neutral red uptake (NRU) and reduction of 2,5-diphenyl-3,-(4,5-dimethyl-2-thiazolyl)tetrazolium bromide (MTT) assays were performed as in vitro endpoints to evaluate cytotoxicity and phototoxicity in a 3T3 cell line, and predict toxicity and/or phototoxicity after systemic administration of the drug. The in vitro alkaline single-cell electrophoresis (comet) assay was used to evaluate the genotoxic and photogenotoxic potential of the substances using the same cell line. RESULTS: The results showed that the SI and the DP are more cytotoxic and phototoxic than the drug GFM using the 3T3 cell line. In the comet assay, the drug GFM was found to be more genotoxic and photogenotoxic than its related substances. CONCLUSIONS: Our findings highlight the relevance of the biological safety studies to increase the knowledge regarding the toxic potential of the related substances, which can be associated with the drug side effects and toxicity.

Determination of fesoterodine in a pharmaceutical preparation by a stability-indicating capillary zone electrophoresis method.

A simple, stability-indicating capillary zone electrophoresis (CZE) method was developed and validated for the analysis of fesoterodine (FESO) in tablets. Optimal conditions for the separation of FESO and its degradation products were investigated. The method used 10 mM sodium phosphate buffer at pH 6.5 as the background electrolyte with an applied voltage of 30 kV (positive polarity).The capillary length was 80.5 cm (72 cm to the detector), and the detection wavelength was 208 nm. The method was validated in accordance with the International Conference on Harmonization requirements, which involved specificity, linearity, precision, accuracy, robustness, LOD, and LOQ. The stability-indicating capability of the method was established by stress degradation studies combined with peak purity assessment using photodiode array detection. The method was linear over the concentration range of 2-100 microg/mL (r2 = 0.9998) of FESO. Intraday and interday precision and accuracy evaluated by RSD, respectively, were all lower than 2%. The LOD and LOQ were 0.57 and 1.90 microg/mL, respectively. The method proved to be robust by a fractional factorial design evaluation. The proposed CZE method was successfully applied for the quantitative analysis of FESO in extended-release tablets to support its QC.

Micellar electrokinetic chromatographic method for mianserin hydrochloride and analysis of degradation products by mass spectrometry.

A simple, stability-indicating micellar electrokinetic chromatography (MEKC) method was developed and validated for the analysis of mianserin hydrochloride in coated tablets. The method employed (hydroxymethyl)aminomethane (TRIS) 50 mM to which sodium dodecyl sulfate (SDS) 50 mM was added at pH 10.6 as the electrolyte and the voltage applied was 25 kV. The capillary used was 48.5 cm long (40.0 cm effective length and 50.0 µm i.d.) and the detection wavelength was 220 nm. Tetracycline was used as internal standard. The method was validated in accordance with the International Conference on Harmonization (ICH) requirements, which involved specificity, linearity, precision, accuracy and robustness. The stability-indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using photodiode array detection. The degradation products formed under photolytic and oxidative conditions were investigated by electrospray ionization mass spectrometry. The method was linear over the concentration range of 50-130 µg/mL. The method was precise as demonstrated by an inter-day and intra-day relative standard deviation of less than 2.0%. The proposed validated MEKC method showed recoveries between 98.16 and 102.80% of the nominal contents. The Plackett-Burman design was applied for the robustness test in order to examine potential sources of variability by screening a large number of factors in a relatively small number of experiments.

Second-Order Derivative UV Spectrophotometric Method for the Determination of Fesoterodine and Comparison with LC, CE and LC-MS/MS in Commercial Extended-Release Tablets.

The present work describes a second-order derivative UV spectrophotometric method for determination of a potent antimuscarinic drug, fesoterodine, in extended-release tablets. The method was developed and satisfactory validated according to ICH guideline with respect to specificity, linearity, precision, accuracy, and robustness. The response was linear in the concentration range of 2-24 µg mL-1 (r2 = 0.9999, n = 7) at wavelength 228 nm, which was the zero crossing point of excipient solutions. The detection and quantitation limits were 0.38 and 1.27 µg mL-1, respectively. Precision and accuracy data evaluated by relative standard deviation were lower than 2%. The method proved to be robust by a Plackett-Burman design evaluation. It is simple, it has low cost, and it has low use of polluting reagents. Therefore, the proposed method was successfully applied for the quantitative analysis of fesoterodine in commercial tablets, and the results were compared to validated methods by liquid chromatography, capillary electrophoresis and liquid chromatography-tandem mass spectrometry showing non-significant difference (P > 0.05).

Simultaneous determination of aliskiren and hydrochlorothiazide from their pharmaceutical preparations using a validated stability-indicating MEKC method.

A stability-indicating MEKC method was developed and validated for the simultaneous determination of aliskiren (ALI) and hydrochlorothiazide (HCTZ) in pharmaceutical formulations using ranitidine as an internal standard (IS). Optimal conditions for the separation of ALI, HCTZ and its major impurity chlorothiazide (CTZ), IS and degradation products were investigated. The method employed 47 mM Tris buffer and 47 mM anionic detergent SDS solution at pH 10.2 as the background electrolyte. MEKC method was performed on a fused-silica capillary (40 cm) at 28°C. Applied voltage was 26 kV (positive polarity) and photodiode array (PDA) detector was set at 217 nm. The method was validated in accordance with the ICH requirements. The method was linear over the concentration range of 5-100 and 60-1200 µg/mL for HCTZ and ALI, respectively (r(2) >0.9997). The stability-indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using the PDA detection. Precision and accuracy evaluated by RSD were lower than 2%. The method proved to be robust by a fractional factorial design evaluation. The proposed MEKC method was successfully applied for the quantitative analysis of ALI and HCTZ both individually and in a combined dosage tablet formulation to support the quality control.

A set of synthetic data, antibacterial evaluation and bacterial interaction with lipid-core nanocapsules containing fusidic acid.

A set of synthetic data, of antibacterial evaluation against gram-positive bacteria, as well as, the interaction of bacterial with lipid-core nanocapsules containing fusidic acid is presented here. In this data set, the analytical data are detailed; serial microdilution; nanoparticle tracking analysis; transmission electron microscopy; minimum inhibitory concentration; diameter size and zeta potential, and infra-red of the formulations before and after contact with bacteria.

Determination of fesoterodine in pharmaceutical formulations by using liquid chromatography-tandem mass spectrometry.

A simple, fast, sensitive, and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of fesoterodine (FESO) in pharmaceutical formulations was developed and validated using manidipine as internal standard (IS). The LC-MS/MS method was carried out on a Luna C8(2) column (50 mm × 3.0 mm i.d., µm) with a mobile-phase consisting of methanol/0.1% formic acid (90:10, v/v). The mass spectrometry method was performed employing a positive electrospray ionization technique, operating in multiple reaction monitoring mode (MRM), monitoring the transitions of 412.2→223.0 and 611.1→167.0 for FESO and IS, respectively. The total analysis time was 2 min and it was linear in the concentration range of 5-1000 ng mL(-1). Placebo solution and mobile-phase components were evaluated on the specificity test and did not interfere with the analyte or the IS. Intra-day and inter- day precision and accuracy evaluated by RSDs and relative errors, respectively, were lower than 5% for all analytes. The method proved to be robust by a fractional factorial design evaluation. The proposed method was successfully applied for the quantitative analysis of FESO in tablet formulations to support the quality control.

Stress degradation studies and kinetic determinations of duloxetine enteric-coated pellets by HPLC.

A stability-indicating HPLC assay method was developed for the quantitative determination of duloxetine (DLX) in a pharmaceutical dosage form in the presence of its degradation products, and kinetic determinations were evaluated in acid conditions and UV-C radiation exposure. Chromatographic separation was achieved by use of an ACE C18 column (250 x 4.0 mm id, 5 microm particle size). The mobile phase was prepared by mixing aqueous 50 mM potassium phosphate buffer (pH 6.0 containing 0.3% triethylamine) and acetonitrile (60 + 40, v/v). DLX was rapidly degraded in an acid medium and in the presence of hydrogen peroxide and UV-C radiation; it was more stable in alkaline medium. The described method was linear over a range of 4.0-14.0 microg/mL for determination of DLX (r = 0.9998). The precision was demonstrated by the RSD of intraday (0.79-1.07%) and interday (0.85%) studies. The mean recovery was found to be 100.56%. The acid degradation of DLX in 0.1 M HCI solution showed an apparent zero-order kinetics (k = 0.177 microg/mL/min), and the photodegradation demonstrated an apparent first-order kinetics (k = 0.082 microg/mL/min). The developed method was found to be simple, specific, robust, linear, precise, and accurate for the determination of DLX in enteric-coated pellets.