Linagliptin Research Articles

Insights into the lipophilicity of four commonly prescribed antidiabetic drugs and their simultaneous analysis using a simple TLC-spectrodensitometric method: Application to fixed-dose combination tablets and human plasma

The retention and lipophilicity characteristics of four oral antidiabetic drugs namely; Metformin (MET), Linagliptin (LIN), Empagliflozin (EMP), and Dapagliflozin (DAP) were evaluated by a facile TLC-spectrodensitometric method. The developed method was validated and employed for simultaneous determination of the investigated drugs in their synthetic quaternary mixture, single- and multi-component tablets, and human plasma. The separation of the cited drugs was achieved using silica gel G 60F254-TLC plates and a mobile system consisting of n-butanol: water: glacial acetic acid (7: 3: 1, v/v/v). After scanning at 234 nm, good linearities (10.0–2000.0 ng/band for each drug) and correlation coefficients (r = 0.99882–0.99972) with lower limits of detection and quantitation (2.17–3.58 and 6.57–10.85 ng/band, respectively) were statistically calculated. The obtained recoveries (98.35–101.38%) proved the wide applicability of the established method for concurrent estimation of the studied antidiabetics in fixed-dose combination tablets and human plasma. Besides, the present work was extended to estimate the lipophilicity parameters of the targeted drugs. Molecular lipophilicity (RM), relative lipophilicity (RM0), and lipophilic descriptor (C0) were calculated for MET, LIN, EMP, and DAP. Good correlations (r = 0.8729–0.9933) between the chromatographic retention data and molecular descriptors of the studied drugs were attained. The obtained results confirmed the poor lipophilicity of MET and LIN compared to EMP and DAP. Lastly, understanding the lipophilicity of the cited drugs may be promising for the future design of safer and more effective formulations for diabetes mellitus, cancer, and Alzheimer’s disease. Over and above, this work may be further applied to QSAR studies.

Analytical quality by design based on design space in reversed-phase-high performance liquid chromatography analysis for simultaneous estimation of metformin, linagliptin and empagliflozin.

Employing the Quality by Design paradigm through this work helped conclude the method operable design region for optimizing the high performance liquid chromatography (HPLC) assay using Design of Experiments and response surface methodology to obtain a good resolution and determination of all analysed compounds and to achieve a suitable analysis time. A deep understanding of the quality target product profile, analytical target profile and risk assessment for parameters that affect the method performance led to developing an accurate, precise and cost-effective method. Quality risk management principles were applied for determining the critical method parameters affecting the simultaneous determination of metformin hydrochloride (MET), linagliptin (LIN) and empagliflozin (EMP) by reversed-phase HPLC . The ternary mixture was successfully resolved in 5 min with a linearity range of (0.1–600) µg ml−1 for MET and (0.05–50) µg ml−1 for LIN and EMP. The newly developed method was validated according to the International Council for Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines. Good agreement was observed with the assay results of the reported UPLC one. To evaluate the greenness of the proposed method, an analytical Eco-Scale method was used.

Application of Molecularly Imprinted Poly-Itaconic/Multiwalled Carbon Nanotubes for Selective and Sensitive Electrochemical Detection of Linagliptin

In this work, we report the first molecularly imprinted polymer (MIP) based electrochemical sensor for the determination of the antidiabetic drug Linagliptin (LNG) in pure sample, tablets, and spiked human urine and serum samples. Using a graphite electrode, differential pulse voltammetry (DPV) was applied to study the electrochemical behavior of LNG in a Britton Robinson (BR) universal buffer of pH 8 with Ag/AgCl electrode and Pt wire. The sensor is based on the modification of the traditional carbon paste sensor with Itaconic acid (IA) as monomer, which cross-linked using ethylene glycol dimethacrylate (EGDMA) and multiwalled carbon nanotubes (MWCNTs) as a modifier. The different factors were optimized, such as ratio of MIP components, percentage of multiwalled carbon nanotubes (MWCNT), pH, accumulation time, accumulation potential and scan rate. The proposed sensor was characterized morphologically using: Scanning electron Microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) and electrochemically applying electrochemical impedance spectroscopy (EIS)and cyclic voltammetry (CV). DPV was applied to obtain the calibration curve and optimization of different factors, the proposed sensor shows a wide linear range of 1 × 10−12M (0.47 ng l−1) to 1 × 10−7M (47.26 μg l−1) and limit of detection (LOD)1 × 10−13M (0.05 ng l−1) while the limit of quantification (LOQ)was found to be 3.3 × 10−13M (0.16 ng l−1) in addition to good reproducibility and selectivity.

New enantioselective liquid chromatography method development and validation of dipeptidyl peptidase IV inhibitors using a macrocyclic glycopeptide (vancomycin) chiral stationary phase under polar ionic mode condition.

The direct separation of dipeptidyl peptidase IV (DPP-4) inhibitors such as Sitagliptin (STG), Linagliptin (LIG), and Saxagliptin (SAG) enantiomers in normal phase conditions have been achieved on immobilized polysaccharide-based chiral stationary phases (CSPs), as well as on the macrocyclic glycopeptide vancomycin chiral stationary phase (Chirobiotic V2) under polar ionic mode. The enantiomers of these targets could be separated completely (resolution factor Rs > 2) using the Chirobiotic V2 column in polar ionic mode with the mobile phase (MeOH/AcOH/TEA 100/0.3/0.1 v/v/v) in an isocratic elution at 1.0 ml min-1 . The effect of the mobile phase composition on separation, including buffer salts, acid-base modifiers, and analyte structures, was evaluated. The developed technique was validated in the polar ionic mode according to the International Conference on Harmonization (ICH) Q2R1 guidelines in terms of accuracy, precision, selectivity, linearity, limit of detection (LOD), and limit of quantification (LOQ). The calibration curve was linear in a concentration range from LOQ to 3.75 μg/ml. The LOD and LOQ of STG, LIG, and SAG were 0.15 and 0.45, 0.15 and 0.50, 0.16 and 0.50, respectively. The proposed method is said to be selective, accurate, and precise. Finally, the validated method was used successfully for the quantitative determination of DPP-4 enantiomers in pharmaceutical analytes.

Synthesis and characterization of a new reusable calix[4]arene-bonded silica gel sorbent for antidiabetic drugs

A novel calix[4]arene-bonded silica gel (C4BS) is prepared by covalent attachment of a calix[4]arene derivative to silica gel through a thiol–ene process. The structure and properties of C4BS were studied by Fourier Transform Infra-Red (FTIR) spectroscopy, thermal gravimetric analysis (TGA), elemental analysis (CHN), scanning electron microscopy (SEM), and surface area analysis (BET). In addition, the binding affinity of some antidiabetic drugs towards C4BS was investigated, by quantitative measurement of the drugs in aqueous solution using UV-visible spectroscopy. Results showed that C4BS has higher affinities than plain silica gel for binding to empagliflozin, dapagliflozin and linagliptin at neutral pH, while metformin hydrochloride was not adsorbed efficiently using either C4BS or plain silica gel. Thus, C4BS can be introduced as a promising binder for selective adsorption of the quoted antidiabetic drugs in pharmaceutical effluents, while being reusable by aqueous/acetonitrile (1 : 1) extraction.

Novel UV Spectrophotometer Methods for Quantitative Estimation of Empagliflozin (EMPA) and Linagliptin (Lina) Using Mixed Hydrotropy Solubilization

Simple, precise accurate, novel and safe UV-Spectrophotometric simultaneous equation method developed for the simultaneous estimation of poorly water-soluble drugs Empagliflozin (EMPA) and Linagliptin (LINA) in tablet dosage form using 2M ammonium acetate: 2M sodium citrate and (50:50% W/W) as mixed hydrotropic solution and validated as per ICH guidelines. This Method involves solving of simultaneous equations based on measurement of absorbance at two wavelengths 270 nm and 294 nm (λmax of EMPA and LINA) in hydrotropic solutions. Ammonium acetate and sodium citrate solution did not show any absorbance above 240 nm and thus no interference in the estimation of drugs was seen. EMPA and LINA follow Beers law in the concentration range of 10-50mg/ml and 5-25mg/ml (r2 = 0.999). % Recovery for both the drugs was in the range of 98.50 to99.23 % indicating excellent accuracy. The methods were precise, with a relative standard deviation of less than 2% for both drugs. The developed methods were validated according to ICH guidelines and values of accuracy, precision and other statistical analysis were found to be in good accordance with the prescribed values. Thus, method can be used for routine monitoring of drugs in industry for the assay of bulk drugs and commercial formulation.

Green chromatographic methods for simultaneous micro-determination of empagliflozin, linagliptin with metformin and its pharmacopoeial impurities in pure form and triple combination tablets: A comparative study

Green analytical chemistry (GAC) is gaining great interest with the respect of global environmental pollution control (EPC). Consequently, we have developed two green chromatographic methods for the simultaneous precise and selective estimation of empagliflozin (EMP), linagliptin (LNA) with Metformin (MET) and its pharmacopoeial impurities cyanoguanidine (CGN) and melamine (MLN). The scientific database lacks any analytical reports tackling such concurrent estimation of the five cited analytes. The first developed method is a reversed phase HPLC-DAD employing Agilent C18 column (4.6 × 250 mm, 5 μm p.s.) and a mobile phase composed of methanol and 0.01 M sodium dihydrogen orthophosphate buffer of pH 2.55 (adjusted with orthophosphoric acid) eluted in a gradient mode with detection at 218 and 224 nm.The second method is HPTLC using Merk TLC plates precoated with 60 F 254 silica gel on aluminium sheet as the stationary phase developed with ethanol: ethylacetate: water (3.5: 3:1, v/v/v, respectively) as mobile phase and scanned at 216 and 224 nm. The proposed methods offered neat separation and quantitation of the five analytes in their pure form and in the triple combination tablets. Both methods were validated as per the ICH guidelines in terms of linearity, range, accuracy, precision, specificity and robustness. Moreover, Greenness assessment of the developed methods was carried out using the Analytical Eco-Scale. Further evaluation of the methods’ ecofriendliness and comparison with previously reported methods was performed using NEMI, GAPI and the novel AGREE tool.

An electrochemical molecularly imprinted sensor based on CuBi2O4/rGO@MoS2 nanocomposite and its utilization for highly selective and sensitive for linagliptin assay

The molecularly imprinted polymers (MIP) is an outstanding electrochemical tool that demonstrates good chemical sensitivity and stability. These main advantages, coupled with the material's vast microfabrication flexibility, make molecularly imprinted sensors an attractive sensing device. Herein, it was aimed to develop a state-of-art molecularly imprinted sensor based on CuBi2O4/rGO@MoS2 nanocomposite to be utilized for the detection of linagliptin (LNG), a novel hypoglycemic drug. The electrochemical characterizations of linagliptin on the surface of the modified electrode was examined via cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Several characterization methods including transmission electron microscope (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Energy-dispersive X-ray spectroscopy(EDX), were utilized for electrode characterization. The LNG imprinted voltammetric sensor was developed in 80.0 mM phenol containing 20.0 mM LNG. CuBi2O4/rGO@MoS2 nanocomposite on LNG imprinted screen-printed carbon electrode (SPCE) (MIP/CuBi2O4/rGO@MoS2 nanocomposite/SCPE) exhibited a linear relationship between peak current and LNG concentration in the range 0.07–0.5 nM with a detection limit of 0.057 nM. In the existence of interfering substances, an LNG imprinted electrode was utilized to analyze urine, human plasma, and tablet samples with adequate selectivity. The developed sensor was also illustrated for stability, repeatability, reproducibility, and reusability.

Rapid simultaneous quantitative determination of linagliptin and empagliflozin as antidiabetic drugs using spectrophotometric method based on fuzzy systems and radial basis function neural network in tablet formulation and biological sample

In this study, spectrophotometry method was combined with artificial intelligence techniques for developing a simple, rapid, low-cost, and accurate approach for the simultaneous determination of Linagliptin (LIN) and Empagliflozin (EMPA) as antidiabetic drugs in mixtures and pharmaceutical formulation. Fuzzy inference system (FIS), adaptive Neuro-fuzzy inference system (ANFIS), and radial basis function neural network (RBF-NN) were proposed to predict the concentration of pharmaceutical components. The mean recovery and root mean square error (RMSE) of FIS were 98.44%, 103.50% and 0.0668, 0.1982 for LIN and EMPA, respectively. The mean recovery percentage of 100.07 and 99.83, as well as RMSE of 0.0033 and 0.0176 were obtained for LIN and EMPA, respectively. On the other hand, MSE related to the RBF-NN was found 1.46 × 10−26 and 1.72 × 10−25 for LIN and EMPA, respectively. Analysis of variance (ANOVA) test did not show a significant difference between high-performance liquid chromatography (HPLC) and proposed methods. The mean recovery (between 91.40% and 98.29%) and relative standard deviation (RSD) (lower than 0.5%) revealed that the suggested methods in a complex matrix such as urine had good predictive ability. Due to the obtained results, these methods can be used in quality control.

Spectroscopic characterization and Electronic structure of Linagliptin by DFT analysis method

Linagliptin (LGP) is the one of the most important drug in type 2 diabetes. In this compound to study on the spectroscopic and electronic behavior by the quantum mechanical method. The optimized molecular structure, electronic properties, dipole moment, rotational constants and important thermodynamic parameters of LGP molecule are computed and compared using HF (Hartree-Fock) and DFT( Density Functional Theory ) methods with 6-311++G (d,p) basis sets. Spectroscopic characterization of experimental FT-IR and Raman frequencies are compared with the calculated scaled vibrational frequencies and also compared theoretical and experimental obtained wavelengths of maximum absorption (λmax) of LGP in different solvents of water, ethanol, and methanol are calculated by the TD-DFT method. The various types of intra-molecular interactions such as conjugative, hyper conjugative and other structural effects are analyzed in Natural bonds orbital of LGP. The relationship between linear polarizability (α) and refractive index (n) was used to describe the polarization behavior of LGP in a different solvent. The electronic charge density at different positions and reactivity descriptors of LGP are used in identifying the site of drug interaction. The various intra-molecular interactions were explained in terms of HOMO and LUMO energies. Mulliken charges and thermodynamic properties of LGP are discussed.

Stability indicating HPLC-Fluorescence detection method for the simultaneous determination of linagliptin and empagliflozin in their combined pharmaceutical preparation

A sensitive, accurate, and precise liquid chromatographic method has been developed and validated for the determination of Linagliptin (LNG) and Empagliflozin (EMP) in their combined tablets. Chromatographic separation was carried out on ODS-3 Inertsil® C18 column (150×4.6 mm, 5 µm). The mobile phase A (consisting of 0.30% Triethyl amine buffer (TEA) at pH = 4.5, adjusted using ortho-phosphoric acid); the mobile phase B (consisting of acetonitrile) was pumped through the column whose temperature was maintained at 40 °C, with a flow rate 1.7 mL/min, using gradient elution from 0-3 min A:B (75:25, v:v), then from 3-6 min the ratio changed to be A:B (60:40, v:v). Fluorescence detection (FLD) was performed at 410 nm after excitation at 239 nm. Acceptable linearity, accuracy and precision values of the proposed method were found over the concentration ranges of 0.5-15 µg/mL for LNG and 1.0-30 µg/mL for EMP with correlation coefficients of 0.9997 and 0.9998 in the case of LNG and EMP, respectively. The recoveries and relative standard deviations percentages were found in the following ranges: 98.56-101.85 and 0.53-1.52% for LNG and 98.00-101.95 and 0.31-1.05% for EMP. The detection and quantification limits were 0.15 and 0.45 µg/mL for LNG and 0.22 and 0.67 µg/mL for EMP. The optimized method was validated and proved to be specific, robust, accurate and reliable for the determination of the drugs in pure form or in their combined pharmaceutical preparations. No significant difference was found regarding accuracy and precision upon statistical comparison between the obtained results of the proposed method and those of the reported method. Furthermore, the proposed method is proved to be a stability-indicating assay after exposure of the studied drugs to variable forced degradation parameters, such as acidic, alkaline and oxidative conditions, according to the recommendations of the International Conference on Harmonization guidelines. The simplicity and selectivity of the proposed method allows its use in quality control laboratories.

Interactions of linagliptin, rabeprazole sodium, and their formed complex with bovine serum albumin: Computational docking and fluorescence spectroscopic methods.

The foremost aim of this thermodynamic study was to evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) profiles of linagliptin (LG), rabeprazole sodium (RS), and their 1:1 formed complex by interacting with bovine serum albumin (BSA) at physiological pH 7.4. The molecular interactions of these ligands with the desired biomolecule were substantiated by the spectral quelling of fluorescence intensity of BSA. The fluorescent test and molecular docking revealed that the quenching mechanism was a spontaneous and exothermic static process, and the protein gained its secondary structure due to the interactions. The spectroscopic method was exercised to determine the thermodynamic factors that supported the interactions mediated by van der Waals forces and hydrogen bonds. The activation energy of the formed complex was higher than its precursor drugs while interacting with BSA, and the energy transformation profiles were studied by UV-fluorescence overlaid curves according to Förster resonance energy transfer (FRET) theory. The double log plot verified that these ligands bound with protein at a 1:1 ratio, which was confirmed by the approximately estimated values of the binding parameters. The drastically lower value of the binding constant of the formed complex suggested the lower half-life as well as its triggered elimination rate from the cardiovascular system, which may be an initial indicator of the reduced hypoglycemic property of linagliptin. Moreover, the UV-vis and synchronous fluorescence spectroscopic methods affirmed the conformational changes of the BSA due to drug-protein complexation and polarity alterations in the microenvironment of disparate chromophores of the biomolecule.

Developed rapid spectrophotometric method for simultaneous quantitative determination of metformin and linagliptin mixture as antidiabetic drugs by artificial intelligence methodology in biological fluid and pharmaceutical sample

In this study, simultaneous measurement of metformin (MET) and linagliptin (LIN) present in synthetic mixtures, antidiabetic tablet, and the biological sample was studied by chemometrics methods along with spectrophotometric technique. These procedures involved feedforward-backpropagation neural network (FFBP-NN) with Levenberg–Marquardt (LM) and comprehensive Grobner bases (CGB) algorithms, as well as least square support vector machine (LS-SVM). The mean square error (MSE) of the LM algorithm was obtained 1.22 × 10−28 (layer=2 with 10 neurons) and 1.93 × 10−27 (layer=3 with 8 neurons) for MET and LIN, respectively. In the CGB algorithm, layer 2 with 10 neurons for both components was introduced as the best layer and neurons with the least error. The optimal parameters of the LS-SVM method, including regularization (γ) and width (σ) parameters with the root mean square error (RMSE) of 0.4416 and 0.1634 were found for MET and LIN, respectively. The proposed methods were implemented on antidiabetic tablet and the results were compared with high-performance liquid chromatography (HPLC) using analysis of variance (ANOVA) test. The urine sample was also studied as a complex matrix by these methods. A combination of spectrophotometry and chemometrics can be used to improve the quality of pharmaceutical products due to its fast and low-cost and no need for the separation step.

Voltammetric determination of linagliptin in bulk and plasma sample using an electrochemical sensor based on L-cysteine modified 1T-MoS2 nanosheets

In this work, a sensitive and selective electrochemical method using L-cysteine (L-cys) decorated MoS2 modified glassy carbon electrode (L-cys@MoS2/GCE) was developed for the determination of linagliptin (LIN). The characterization of L-cys@MoS2 was performed by Fourier transform infrared spectroscopy (FTIR), x-ray diffraction spectroscopy (XRD), x-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The method using differential pulse voltammetry (DPV) exhibited two linear working ranges in the concentration ranges of 1.0–75.0 µM and 75.0–153.4 µM with a limit of detection (LOD) value of 0.19 µM. The method was also applied to detect the LIN quantity of the plasma sample with satisfactory recovery results. To sum up, the developed method was successfully applied to the determination of LIN in bulk and plasma samples, and it may be a promising way for the detection of LIN for quality evaluation and clinical monitoring.

Electrochemical sensor based on GCE modified with E-rGO/Poly (B-CD)/magnetic ZIF-67 nanocomposite for the measurement of Linagliptin

Linagliptin (LNG) is one of the drugs that was entered the market in 2011 to treat type 2 diabetes. The drug inhibits the dipeptidyl peptidase-4 enzyme in human body and regulates the insulin level which decreases blood sugar in diabetics. In this work, firstly, GO and magnetic ZIF-67 were synthesized. The modification of the glassy carbon electrode (GCE) was performed layered by layer. GO was reduced on the electrode surface by the electrochemical method (E-rGO). Then β-cyclodextrin was electrodeposited (Poly (β-CD)) on the E-rGO. Finally, Fe3O4@ZIF-67 (magnetic ZIF-67) nanocomposite was cast on the E-rGO-Poly (β-CD) and was let dry at room temperature completely and was used as a very sensitive sensor to measure the LNG. The performance of the prepared electrodes was evaluated using cyclic voltammetry, electrochemical impedance, spectroscopy, and field emission scanning electron microscopy methods. The results showed that the oxidation current of LNG on the surface of the modified electrodes at a potential of 1.0 V is much higher than that of the GCE. The high surface area of GCE/E-rGO/Poly (B-CD)/magneticZIF-67 showed that the effective synergistic effect of rGO, B-CD, and magneticZIF-67 for the oxidation of LNG, so that the current at the surface of GCE/E-rGO/Poly (B-CD)/magnetic ZIF-67 was 4 times that of the unmodified electrode. Applicability of the sensor was monitored in various concentrations of LNG under linear ranges of 0.03–200 μM and a limit of detection of 0.01 μM was resulted. Also, the sensor showed a good ability to measure LNG in the presence of other species.

Innovative TLC-densitometric method with fluorescent detection for simultaneous determination of ternary anti-diabetic mixture in pharmaceutical formulations and human plasma

Co-administration of Glimepiride (GLIM), Empagliflozin (EMPA) and Linagliptin (LING) promote a preferred glycemic control, besides additional benefits such as reduction of high blood pressure and weight loss. In the present study a feasible TLC method with reflectance/ fluorescence mode for simultaneous determination of GLM, EMPA and LING was established. Separation of the cited drugs was performed on aluminum plates pre-coated with silica gel 60 F254 and developed with (toluene: methanol: ethyl acetate (4: 3: 2 v/v/v)) as a mobile phase. The mentioned drugs were adequately detected after exposing the plate to concentrated (30–34%) hydrochloric acid vapor for 15 min. The was scanned in the reflectance/fluorescence mode at 228 nm excitation wavelength using 320 nm emission filter. The three drugs were well separated with Rf values of 0.73 ± 0.02, 0.59 ± 0.02 and 0.10 ± 0.02 for GLIM, EMPA and LING, respectively. The developed method was validated according to ICH guideline with linearity (2.61–60, 5.53 –120 and 4.68–80 ng/band for GLIM, EMPA and LING, respectively) and precision (% RSD was ± 2.98 for GLIM, 2.76 for EMPA, 2.41 for LING). The correlation coefficients were 0.9915, 0.9940 and 0.9921 for GLIM, EMPA and LING, respectively. The developed method was successfully applied for the analysis of the cited drugs in their tablets and real human plasma samples with good accuracy and precision.

Square Wave Anodic Voltammetric Determination of Antidiabetic Drug Linagliptin in The Dosage Form and Biological Fluids by Microparticles Copper Pencil Graphite Electrode

A new simple, cheap, and rapid method to increase the sensitivity of pencil graphite electrode (PGE) to determine Linagliptin (LNG) was developed by modified PGE with copper microparticles (Cu-PGE). The disposable modified sensor electrode's preparation depended on the electrodeposition of Cu-microparticles on the PGE that can be applied for determined LNG by complexed it with Cu+2 ions and measure the LNG-Cu complex onto the Cu-PGE improved. The preparation of this modified electrode is easy, simple, and cheap, and has high sensitivity. The modified electrode detected the LNG in the LNG-Cu complex range from 47.25 - 283.53 ng mL-1 with detection and quantitative limits of 6.0 and 20.0 ng mL-1, respectively, with a correlation coefficient of 0.9995. The proposed method was applied with success to determined LNG in the dosage form, spiked urine, and spiked plasma samples; additionally, the obtained modified electrode was put in comparison with the reported electrodes.

An RP-HPLC Method for Quantitative Analysis of Linagliptin Entrapped in Nanotransfersomes and its Application to Skin Permeation Studies

Background:Linagliptin (LNG) is an oral hypoglycemic agent that acts by inhibiting the enzyme dipeptidyl peptidase - 4 (DPP-4) and reduces blood sugar levels in type-II diabetic patients. To date, the literature presents few analytical methods for the determination of LNG. However, no reversed phase-high performance liquid chromatography (RP-HPLC) method has been reported for the determination of LNG in nanotransfersomes and in vitro skin permeation samples.Objective:The present study involves the development and validation of RP-HPLC method to quantify LNG in both nanotransfersomes and in vitro skin permeation and deposition samples.Methods:The chromatographic analysis was performed on Luna C18 (2) column (250 x 4.6 mm, 5μm particle size) with a mobile phase consisting of a mixture of methanol: 0.2% orthophosphoric acid (50:50, v/v) at a flow rate of 1.0 mL/min, detection wavelength of 227 nm, and column temperature of 40 °C.Results:The method was found to be specific, linear (r2≥ 0.999; 2-12 μg/mL), precise at both intra and inter-day levels (percentage relative standard deviation; % RSD < 2.00), accurate (percentage recovery 100.21-103.83%), and robust. The detection and quantification limits were 0.27 and 0.82 μg/mL, respectively. The mean % entrapment efficiency and the cumulative amount of LNG permeated across the rat skin from different transfersomal formulations ranged between 40.78 ± 2.54 % to 52.26 ± 2.15 % and 79.54 ± 16.67 to 200.74 ± 35.13 μg/cm2respectively.Conclusion:The method was successfully applied to determine the entThe method was successfully applied to determine the entrapment efficiency, in vitro skin permeation and deposition behavior of LNG-nanotransfersomes.rapment efficiency, in vitro skin permeation and deposition behavior of LNG-nanotransfersomes.

Effect of linagliptin versus placebo on cardiovascular and kidney outcomes in nephrotic-range proteinuria and type 2 diabetes: the CARMELINA randomized controlled trial.

BackgroundNephrotic-range proteinuria (NRP) is associated with rapid kidney function loss and increased cardiovascular (CV) disease risk. We assessed the effects of linagliptin (LINA) on CV and kidney outcomes in people with Type 2 diabetes (T2D) with or without NRP.MethodsCardiovascular and renal microvascular outcome study with LINA randomized participants with T2D and CV disease and/or kidney disease to LINA 5 mg or placebo (PBO). The primary endpoint [time to first occurrence of 3-point major adverse cardiac events (3P-MACE)], and kidney outcomes, were evaluated by NRP status [urinary albumin:creatinine ratio (UACR) ≥2200 mg/g] at baseline (BL) in participants treated with one or more dose of study medication.ResultsNRP was present in 646/6979 [9.3% (LINA/PBO n = 317/n = 329); median UACR 3486 (Q1: 2746/Q3: 4941) mg/g] participants, who compared with no-NRP were younger (62.3/66.1 years) and had lower estimated glomerular filtration rate (eGFR) (39.9/56.1 mL/min/1.73 m2). Over a median of 2.2 years, 3P-MACE occurred with a 2.0-fold higher rate in NRP versus no-NRP (PBO group), with a neutral LINA effect, regardless of NRP. The composite of time to renal death, end-stage kidney disease (ESKD) or decrease of ≥40 or ≥50% in eGFR, occurred with 12.3- and 13.6-fold higher rate with NRP (PBO group); evidence of heterogeneity of effects with LINA was observed for the former [NRP yes/no: hazard ratio 0.80 (0.63–1.01)/1.25 (1.02–1.54); P-interaction 0.005], but not the latter [0.83 (0.64–1.09)/1.17 (0.91–1.51), P-interaction 0.07]. No heterogeneity was observed for renal death or ESKD [0.88 (0.64–1.21)/0.94 (0.67–1.31), P-interaction 0.79]. Glycated haemoglobin A1c (HbA1c) was significantly reduced regardless of NRP, without increasing hypoglycaemia risk. Regression to normoalbuminuria [1.20 (1.07–1.34)] and reduction of UACR ≥50% [1.15 (1.07–1.25)] from BL, occurred more frequently with LINA, regardless of NRP status (P-interactions >0.05).ConclusionsIndividuals with T2D and NRP have a high disease burden. LINA reduces their albuminuria burden and HbA1c, without affecting CV or kidney risk.

Simultaneous Determination of Alogliptin, Linagliptin, Saxagliptin, and Sitagliptin in Bulk Drug and Formulation by UPLC Q-TOF-MS

Background: A simple and sensitive Ultra Performance Liquid Chromatography-Mass Spectrometry method was developed and validated to measure the concentrations of Alogliptin (ALO), Linagliptin (LIN), Saxagliptin (SAX), and Sitagliptin (SIT) using Pioglitazone (PIO) as an internal standard. Methods: Chromatographic separation of six gliptins was achieved on a C-18 column (100×2.1 mm, 2.7 μm) using a mobile phase consisting of formic acid in water, 0.1%v/v: acetonitrile in gradient elution. Electrospray ionization (ESI) source was operated in the positive ion mode. Targeted MS/MS mode on a QTOF MS was used to quantify the drug utilizing the transitions of 340.1(m/z), 473.2 (m/z), 316.2 (m/z), 408.1 (m/z), and 357.1 (m/z) for ALO, LIN, SAX, SIT and PIO respectively. Results: As per ICH Q2R1 guidelines, a detailed validation of the method was carried out and the standard curves were found to be linear over the concentration ranges of 1516.0-4548.1 ng mL-1, 519.8- 1559.4 ng mL-1, 1531.4-4594.3 ng mL-1and 1519.6-4558.8 ng mL-1 for ALO, LIN, SAX and SIT respectively. Precision and accuracy results were within the acceptable limits. The mean recovery was found to be 98.8 _ 0.76 % (GEM), 102.2 _ 1.59 % (LIN), 95.3 _ 2.74 % (SAX) and 99.2 _ 1.75 % (SIT) respectively. Conclusions: The optimized validated UPLC QTOF-MS/MS method offered the advantage of shorter analytical times and higher sensitivity and selectivity. The optimized method is suitable for application in quantitative analysis of pharmaceutical dosage forms for QC laboratory.