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.

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.

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.

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.

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.

UPLC-ESI/Q-TOF MS/MS Method for Determination of Vildagliptin and its Organic Impurities.

Vildagliptin (VLG) corresponds to a drug used for the treatment of diabetes mellitus. This disease requires continuous treatment, and so the control of impurities present in it is important to assure the quality of this drug. Thus, it is necessary to use sensitive and selective detection techniques and the ultra-performance liquid chromatography is a better option compared with high-performance liquid chromatography because it enhances the separation efficiency with a shorter analysis time and an increased resolution. This research analysis was accomplished by using liquid chromatography/tandem mass spectrometry, and the quantification was performed by using an extracted ion from the VLG drug and its main organic impurities of synthesis. During the validation process, following international standards, the method proved to be linear for the tree substances (R2 = 0.997-0.998) and the analysis of variance showed a non-significant linearity deviation (P > 0.05). Three critical factors were selected to evaluate method robustness with a full factorial experimental design, and the changes in the parameters were found to be not significant for the quantification of VLG and its impurities. The ultra-performance liquid chromatography-tandem mass spectrometry for the determination of impurities in VLG was precise, accurate and robust proving to be effective for analysis in the pharmaceutical industry and to improve the quality, safety and effectiveness of the new drug developed.

The application of quality by design in the development of the liquid chromatography method to determine empagliflozin in the presence of its organic impurities.

Analysis of impurities is an important step in the quality control of pharmaceutical ingredients and final products. From drug synthesis or excipients, even in small concentrations, impurities may affect efficacy and safety. The method was developed following Quality by Design (QbD) for the analysis of the antidiabetic empagliflozin. The concept of QbD is used as a tool for the development of methods and formulations. Through predefined objectives and risk analysis, robust methodologies and reduced solvent consumption are developed. A simple HPLC method was developed and validated for the quantitative determination of empagliflozin and its organic impurities from the synthesis process. The method was carried out in a Shim-pack phenyl column with a mobile phase consisting of an acetonitrile/water mixture (72 : 28), with isocratic elution and the detector wavelength was 230 nm. The validation process, in accordance with international guidelines, shows that the method was linear, precise and accurate for empagliflozin, impurity 1 and impurity 2. Limits of detection (0.01, 0.02 and 0.01 µg mL-1) and quantification (0.10, 0.10 and 0.05 µg mL-1) were determined for EMPA, IMP1 and IMP2, respectively. The HPLC method for impurity determination in empagliflozin was linear, precise, accurate and robust. It can be successfully applied in the quality control of empagliflozin and the synthesis of impurities, being adequate for routine analysis.

In vitro toxic evaluation of two gliptins and their main impurities of synthesis.

BACKGROUND: The presence of impurities in some drugs may compromise the safety and efficacy of the patient's treatment. Therefore, establishing of the biological safety of the impurities is essential. Diabetic patients are predisposed to tissue damage due to an increased oxidative stress process; and drug impurities may contribute to these toxic effects. In this context, the aim of this work was to study the toxicity, in 3 T3 cells, of the antidiabetic agents sitagliptin, vildagliptin, and their two main impurities of synthesis (S1 and S2; V1 and V2, respectively). METHODS: MTT reduction and neutral red uptake assays were performed in cytotoxicity tests. In addition, DNA damage (measured by comet assay), intracellular free radicals (by DCF), NO production, and mitochondrial membrane potential (ΔψM) were evaluated. RESULTS: Cytotoxicity was observed for impurity V2. Free radicals generation was found at 1000 µM of sitagliptin and 10 µM of both vildagliptin impurities (V1 and V2). A decrease in NO production was observed for all vildagliptin concentrations. No alterations were observed in ΔψM or DNA damage at the tested concentrations. CONCLUSIONS: This study demonstrated that the presence of impurities might increase the cytotoxicity and oxidative stress of the pharmaceutical formulations at the concentrations studied.

Biological Safety Studies and Simultaneous Determination of Linagliptin and Synthetic Impurities by LC-PDA.

A stability-indicating LC method was developed for quantification of linagliptin (LGT) and three synthetic impurities. The method utilizes a Thermo Scientific® RP-8 column (100 mm × 4.6 mm; 5 µm) with the PDA detector for quantitation of impurities. A mixture of 0.1% formic acid with pH 3.5 (A) and acetonitrile (B) was used as the mobile phase at a flow rate of 0.6 mL·min-1 with gradient elution. The percentage of mobile phase B increases from 30% to 70% over 5 min and decreases from 70% to 30% between 5 and 8 min. The method was validated according to International Council for Harmonization (ICH) guidelines. The LOD values obtained were 0.0171 µg·mL-1 and 0.015 µg·mL-1 for LGT and impurities, respectively. The LOQ values were 0.06 µg·mL-1 for LGT and impurities. In all cases, the correlation coefficients of LGT and impurities were >0.999, showing the linearity of the method. The % recovery of the LGT and added impurity were in the range of 92.92-99.79%. The precision of the method showed values less than 1.47% for LGT and less than 4.63% for impurities. The robustness was also demonstrated by small modifications in the chromatographic conditions. The selectivity was evidenced because the degradation products formed in stress conditions did not interfere in the determination of LGT and impurities. Toxicity prediction studies suggested toxicity potential of the impurities, which was confirmed using biological safety studies in vitro.

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.

Quantitative Assessment of Poorly Soluble Anticoagulant Rivaroxaban by Microemulsion Electrokinetic Chromatography.

Microemulsion electrokinetic chromatography (MEEKC) is an electrophoretic methodology based on the separation of compounds by a microemulsionated electrolyte. There are few options for the evaluation of the stability and content of the oral anticoagulant rivaroxaban (RIV) in pharmaceutical formulations. RIV has low water solubility and undergoes ionization only under restricted pH conditions (pH < 1 or pH > 13), thus, hindering the application of free zone capillary electrophoresis as an analytical method. Therefore, the work aimed at developing and validating a stability-indicating MEEKC method for the analysis of RIV in pharmaceutical formulations. Separation was performed in a fused-silica capillary applying a voltage of 30 kV. The microemulsion system consisted of 13 mM tetraborate, pH 9.75 + 1.2% SDS + 1.0% ethyl acetate + 2.4% butanol. The linearity range was 25-150 µg mL-1, with r = 0.9982. Drug degradations were performed in acid and basic media (HCl 1 M and NaOH 0.1 M, respectively), oxidation with 3%H2O2, 60°C temperature and exposure to UV-C radiation. No interferences with RIV or internal standard peaks were detected. Method robustness was accessed through Plackett-Burman experimental design, after evaluation of model validity. Trueness values between 100.49 and 100.68% were obtained with repeatability. The method developed was found appropriate for quality control of RIV tablets, as a consistent analytical technique that is considered less damaging to the environment due to its low consumption of organic reagents.

Application of Quality by Design to optimize a stability-indicating LC method for the determination of ticagrelor and its impurities.

Simultaneous analysis of drug compounds and their impurities of degradation and synthesis became constant in the modern pharmaceutical analysis. Likewise, analytical techniques must improve sensitivity and selectivity for the monitoring of pharmaceutical products, allowing a full assessment of impurities in drug products and, therefore, ensure safety and efficacy of pharmacological treatments. The application of Quality by Design (QbD) principles has proved to be feasible on the elaboration of analytical methods, allowing the comprehensive evaluation and measurement of different analytical parameters and their effects on critical properties of the methodology in development. QbD approach was applied to the development of a fast and selective HPLC method for the analysis of the antiplatelet aggregation drug ticagrelor and its degradation products in presence of three impurities of synthesis. Fractional factorial resolution V was the screening experimental design applied to five method parameters. Response surface methodology was carried by central composite star face design on the two critical method parameters selected. Analytical design space, established after the application of Monte-Carlo simulations, verified whether predicted results were in accordance with critical quality attributes. The developed and validated HPLC method with DAD detection at 225 nm was able to resolve eight related compounds in less than three minutes.

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.

Design, synthesis and structure-activity relationship studies of a novel focused library of 2,3,4-substituted oxazolidines with antiproliferative activity against cancer cell lines.

In the present work we describe the synthesis and antiproliferative evaluation of a focused library of 30 novel oxazolidines designed by modification of N-substituent, by ring variation, by alkyl variation or by extension of the structure. It was noted that carbamate and N,O-aminal groups were essential for activity. In general, replacement of the phenyl ring with pyridinyl was not tolerated. However, the introduction of a second phenyl ring with an appropriate spacer at the 3- or 4-position of the first phenyl ring generally enhanced the cytotoxic profile. Among all the prepared compounds, 24 was the most potent compound found in this class, being active on four of five cancer cell lines and it was 5-fold and 10-fold more potent than the lead compounds against HL60 and JURKAT cells, respectively. In addition, it showed relevant activity against MCF-7 and HCT-116 cells, which were resistant to lead. Moreover, 24 showed little antiproliferative activity against VERO, indicating low toxicity to normal cells. Thus, this compound has the potential to be developed as an anticancer agent.

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.

HPLC method for simultaneous analysis of ticagrelor and its organic impurities and identification of two major photodegradation products.

A simple, fast and sensitive analytical method by high-performance liquid chromatography (HPLC) was developed and validated for the simultaneous determination of ticagrelor and two synthesis impurities. The HPLC method was established using an Agilent 1200 Series equipment coupled to photodiode array detector (PDA) at 270nm with a Zorbax Plus C8 column (150×4.6mm, 5.0µm), injection volume of 20µL, and a constant temperature of 25°C. The mobile phase consisted of acetonitrile: ammonium acetate 50mM (57:43, v/v) and pH adjusted to 8.2 with ammonium hydroxide 6M, at a flow rate of 0.7mL/min. No interference peaks from excipients and diluent system indicated the specificity of the method. The calibration curves showed determination coefficients (r2)>0.99, calculated by linear regression. The limit of quantitation (LOQ) for impurities 1 and 2 were 2.0 and 0.2µg/mL, respectively. Intra and interday relative standard deviations (RSDs) were <2% for ticagrelor and <6% for the impurities, proving the precision of the method. Besides, two mayor degradation products formed when sample solutions of ticagrelor were exposed to UVC radiation were elucidated and the mechanisms involved in the photolytic degradation of ticagrelor were proposed.

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.

Determination of the main impurities formed after acid hydrolysis of soybean extracts and the in vitro mutagenicity and genotoxicity studies of 5-ethoxymethyl-2-furfural.

Soybean acid hydrolyzed extracts are raw-materials widely used for manufacturing of pharmaceuticals and cosmetics products due to their high content of isoflavone aglycones. In the present study, the main sugar degradation products 5-hydroxymethyl-2-furfural (HMF) and 5-ethoxymethyl-2-furfural (EMF) were quantitatively determined after acid hydrolysis of extracts from different soybean cultivars by a validated liquid chromatography method. The furanic compounds determined in samples cover the range of 0.16-0.21mg/mL and 0.22-0.33mg/mL for HMF and EMF, respectively. Complementarily, due to the scarce literature regarding the EMF toxicology, this study also assessed the EMF mutagenicity by the Salmonella/microsome test and genotoxicity by the comet assay. The results revealed that EMF did not show mutagenicity at the range of 50-5000µg/plate in S. typhimurium strains TA98, TA97a, TA100, TA102 and TA1535, but induced DNA damage in HepG2 cells at non-cytotoxic doses of 0.1-1.3mg/mL, mainly by oxidative stress mechanisms. Based on literature of HMF genotoxicity, and considering the EMF genotoxicity results herein shown, purification procedures to remove these impurities from extracts are recommended during healthcare products development to ensure the security of the products.