Linagliptin Research Articles

463-P: Linagliptin Ameliorated Heart Damage Associated with the Suppression of Necroptosis in Type 1 Diabetic Mice

Background: In diabetic patients, the incident of heart failure is two to five times greater when compared to that of general population. The influence of DPP-4 inhibitor on the heart failure and cardiac damage in diabetes is not completely elucidated yet. Therefore, to understand the pathobiology of heart damage in diabetes and the influence of DPP-4 inhibitor is emerged as significant. Necroptosis, recently identified as programmed cell death, had shown to be involved in heart damage of ischemic heart disease model. Here we found that intervention with DPP-4 inhibitor linagliptin (LINA) ameliorated heart damage in diabetic mice associated with the suppression of necroptosis. Method: We utilized streptozotocin-induced diabetic CD-1 mice (STZ:200mg/kg). At 20 weeks after the onset of diabetes, diabetic mice were treated with LINA (STZ+LINA) for 4 weeks. Result: Blood pressure, blood glucose, body and heart weights were not different between STZ and STZ+LINA. Ultrasonic Echocardiography analysis revealed that LVDd and LVDs were significantly decreased in STZ and STZ+LINA compared with control. STZ-induced diabetic CD-1 mice exhibited perivascular fibrosis evaluated by picrosirius red staining and strong immunoreactivity for DPP-4 expression in cardiac interstitium; STZ+LINA exhibited suppression of DPP-4 and amelioration of heart fibrosis. Diabetic CD-1 mice exhibited deficiency in myocardial stripe structure and endothelial damage in electron microscopy; LINA normalized all. When necroptosis was evaluated by associated kinases, RIP3 and MLKL, diabetic CD-1 mice were exhibited a strong RIP3 and MLKL mRNA and protein expression levels in myocyte; LINA suppressed RIP3 and MLKL levels in myocyte. Conclusion: These results indicated that LINA restored cardiac structure associated with suppression of necroptosis in type 1 diabetic mice. Disclosure T. Hirai: None. Y. Takagaki: None. K. Kanasaki: Other Relationship; Self; Astellas Pharma Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Mitsubishi Tanabe Pharma Corporation, Ono Pharmaceutical Co., Ltd., Sanofi, Taisho Toyama Pharmaceutical. D. Koya: Research Support; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Mitsubishi Tanabe Pharma Corporation. Speaker's Bureau; Self; Astellas Pharma Inc., Astellas Pharma Inc., AstraZeneca, Merck & Co., Inc., Mitsubishi Tanabe Pharma Corporation, Taisho Pharmaceutical Co., Ltd. Funding Japan Society for the Promotion of Science

1459-P: Comparative Cardiovascular Safety and Effectiveness of Linagliptin in Routine Care: Final Results from a 5-Year Post-Marketing Monitoring Program

Real world data on the cardiovascular (CV) safety and effectiveness of linagliptin (LINA) complement trial data from CARMELINA, which showed CV safety, and CAROLINA (results pending). As part of a 5-year (05/2011-12/2016) post-marketing monitoring program, using 2 large insurance claims databases, we assessed the risk of a composite CV (cCV) outcome (hospitalization for myocardial infarction, stroke, unstable angina, or coronary revascularization). We identified three 1:1 propensity score (PS)-matched cohorts of type 2 diabetes mellitus patients who initiated linagliptin or a comparator [other DPP-4is (n=39,834 pairs), pioglitazone (PIO; n=29,646 pairs), or sulfonylureas (SU; n=25,285 pairs). We estimated pooled HR and 95% CI controlling for over 180 baseline characteristics. After PS-matching, patient characteristics were similar (Table 1) and mean follow-up was 0.8 years. LINA had a similar risk of the cCV outcome compared to other DPP-4is [HR (95% CI) = 0.90 (0.80-1.02)] and PIO [HR (95% CI) = 0.99 (0.86-1.13)], but was associated with a reduced risk compared to SU [HR (95% CI) = 0.77 (0.66-0.90)] (Table 1). Results were robust across numerous sensitivity analyses. These real-world data show that LINA has reassuring effectiveness and safety on a cCV outcome compared to other DPP-4is and PIO, and is associated with a decreased risk compared to SU. Disclosure E. Patorno: Research Support; Self; National Institute on Aging. Other Relationship; Self; Boehringer Ingelheim International GmbH. C. Gopalakrishnan: None. M. Mahesri: None. K.G. Brodovicz: Employee; Self; Boehringer Ingelheim Pharmaceuticals, Inc. D. Bartels: Employee; Self; BI X GmbH, Boehringer Ingelheim International GmbH. A. Meyers: Employee; Self; Boehringer Ingelheim Pharmaceuticals, Inc. J. Barberio: None. J. Liu: None. S. Schneeweiss: Consultant; Self; Aetion, WHISCON, LLC. Funding Boehringer Ingelheim

Diarylpyrrolone based fluorophore for the selective spectrofluorometric method for determination of Linagliptin antidiabetic drug in pharmaceutical tablets

Linagliptin (LNG) is a type 2 antidiabetic drug which belongs to dipeptidyl peptidase 4 inhibitors. In this paper a simple and sensitive spectrofluorometric method was developed and validated for the determination of LNG. The method employed the interaction of the primary amino group of the cited drug with fluorescamine reagent in aqueous borate buffer (pH 8.5) to produce a highly fluorescent product. The emission of the formed product was measured at 479 nm after excitation at 390 nm. Different experimental parameters that may affect the product formation or its fluorescence intensity were investigated and adjusted. The method has a good linearity in the concentration range of 0.2 – 2.0 μg mL−1of LNG with a detection limit of 0.079 μg mL−1.The performance of the developed method was evaluated according to the International Conference for Harmonization (ICH). The method was successfully applied for the analysis of tablets dosage form that contained the cited drug. The results of the analysis were compared with the reported method and indicated good accuracy and precision of the proposed procedure.

SUN-LB015 Baseline Characteristics and Effects on CV and Kidney Outcomes with Linagliptin Versus Placebo, Across GFR Categories in CARMELINA

People with type 2 diabetes (T2D) with concomitant chronic kidney disease (CKD) and cardiovascular (CV) disease are at increased risk for recurrent CV events and hypoglycemia. Treatment of these individuals is clinically challenging, where the evidence-base for safety and efficacy of glucose lowering drugs is scarce, in particular in GFR categories G3b (eGFR 30-44 ml/min/1.73m2), G4 (eGFR < 30) and G5 (eGFR < 15). We analyzed baseline characteristics and effects on CV and kidney outcomes with the DPP-4 inhibitor linagliptin (LINA) vs. placebo (PBO), across GFR categories in CARMELINA (NCT01897532). People with T2D and either i) UACR >30 mg/g with concomitant CV disease, or ii) eGFR <45 ml/min/1.73m² regardless of UACR, or eGFR ≥45 - 75mL/min/1.73m² and UACR > 200 mg/g, were randomized to LINA 5 mg or placebo (PBO) q.d. in a double-blind fashion. The primary outcome was first occurrence of CV death, non-fatal myocardial infarction, or non-fatal stroke (3P-MACE), with an adjudicated secondary composite outcome of ESKD, renal death, or sustained ≥40% decrease in eGFR from baseline. Other adjudicated outcomes included hospitalized heart failure (hHF) and the 3P-MACE components. Subgroup-effects across GFR categories (G≤2, G3a, G3b and G≥4) were also assessed. Of the 6979 participants, 15.2% were in GFR category G≥4, 27.8% G3b, 19.3% G3a, and 37.7% G≤2 at baseline. Participants in G≥4 (mean±SD eGFR 23.4±4.2 mL/min/1.73m²) or G3b (eGFR 37.2±4.1) as compared with G3a (eGFR 51.4±4.4) and G≤2 (eGFR 81.6±16.7) had more albuminuria, longer T2D duration and were more frequently treated with insulin, but less often with sulfonylureas and metformin. Over a median 2.2 years, LINA did not affect the risk for 3P-MACE (HR.1.02 [95% CI, 0.89, 1.17]), the secondary kidney composite outcome (1.04 [0.89, 1.22]), hHF (0.90 [0.74, 1.08]), or CV mortality (0.96 [0.81, 1.14]). Incidences were higher by declining kidney function, e.g. the 3P-MACE PBO incidence rate was 2.4 fold higher in G≥4 (9.6 per 100 patient-yrs) relative to G≤2 (4.0 per 100-patient yrs), whereas the kidney composite 9.8 fold (14.7 vs 1.5 per 100 patient-yrs), hHF 4.1 fold (6.2 vs 1.5 per patient-yrs) and CV death 3.0 fold (6.8 vs 2.3 per 100 patient-yrs) higher, respectively. A consistent neutral effect was observed across all GFR categories (interaction p-values: 0.84 [3P-MACE], 0.36 [kidney composite], 0.88 [hHF], 0.23 [CV mortality]). Adverse events (AE) increased with declining kidney function, but the proportion with ≥1 AE, or ≥1 serious AE were balanced between LINA and PBO across the GFR categories. HbA1c was reduced significantly, but without increased risk for hypoglycemia with LINA vs PBO, across all GFR categories. These findings in a large, international CV outcome trial in patients with T2D and concomitant CV and renal disease support the safety and tolerability of LINA as a T2D therapy that can be used across a broad range of kidney disease. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

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.

THE IN VITRO CYTOTOXICITY, GENOTOXICITY AND OXIDATIVE DAMAGE POTENTIAL OF THE ORAL DIPEPTIDYL PEPTIDASE-4 INHIBITOR, LINAGLIPTIN, ON CULTURED HUMAN MONONUCLEAR BLOOD CELLS.

Linagliptin (LNG) is a selective dipeptidyl peptidase-4 (DPP-4) inhibitor that ameliorates blood glucose control of patients with type 2 diabetes, without developing hypoglycemic risk and weight gain with a good clinical and biological tolerance profile. To the best of our knowledge, its cytotoxic, genotoxic and oxidative effects have never been studied on any cell line. To evaluate the in vitro cytotoxic, genotoxic damage potential and antioxidant/oxidant activity of LNG in cultured peripheral blood mononuclear cells (PBMC). After exposure to different doses (from 0.5 to 500 mg/L) of LNG, cell viability was measured by the MTT (3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and lactate dehydrogenase (LDH) leakage tests. The antioxidant activity was assessed by the total antioxidant capacity (TAC) and total oxidative stress (TOS) assays. To evaluate the genotoxic damage potential, chromosomal aberration (CA) frequencies and 8-oxo-2'-deoxyguanosine (8-oxo-dG) levels were determined. Treatment with LNG did not cause statistically significant decreases of cell viability at lower concentrations than 100 mg/L as compared to untreated cultures. However, LNG exhibited cytotoxic action at 250 and 500 mg/L. Also, IC20 and IC50 values of LNG were determined as 8.827 and 70.307 mg/L, respectively. In addition, the oxidative analysis revealed that LNG supported antioxidant capacity at concentrations of 2.5, 5, 10, 25, 50 and 100 mg/L without generating oxidative stress. Besides, the results of CA and 8-oxo-dG assays showed in vitro non-genotoxic feature of LNG. As a conclusion, our findings clearly revealed that LNG had no cytotoxic and genotoxic actions, but exhibited antioxidative activity. In conclusion, therefore it is suggested that LNG use in diabetic patients is safe and provides protection against diabetic vascular and oxidative complications.

Cardiovascular Effects of Linagliptin

New diabetes medications must demonstrate cardiovascular (CV) safety. In this manufacturer-sponsored, randomized trial, researchers examined the CV

Effect and its mechanism of Linagliptin on mild cognitive impairment in elderly type 2 diabetes mellitus patients

Objective To investigate the effect and its underlying mechanism of Linagliptin on mild cognitive impairment(MCI)in elderly type 2 diabetes mellitus (T2DM) patients. Methods Montreal Cognitive Assessment(MoCA)scale was used to prospectively screen T2DM patients for MCI in our hospital from December 2016 to June 2017, and a total of 98 elderly T2DM patients with MCI were recruited.They were randomly divided into the linagliptin group(Linagliptin + metformin, n=50)and the non-linagliptin group(gliclazide + metformin, n=48). Serum fasting plasma glucose(FPG), glycosylated hemoglobin(HbAlc), blood lipids and amyloid β-protein 1-42(Aβ1-42)levels were determined, and MoCA score and homeostasis model assessment of insulin resistance(HOMA-IR)were calculated, and were compared between the two groups before and after 24 weeks of treatment. Results In the linagliptin group, serum FPG, HbA1c, HOMA-IR, Aβ1-42 levels were significantly decreased and MoCA score was increased after 24 weeks of treatment as compared with pre-treatment[(7.29±1.00)mmol/L vs.(9.16±1.60)mmol/L, (7.19±0.99)% vs.(9.36±1.07)%, (3.05±1.12) vs.(4.05±1.30), (0.463±0.093)g/L vs.(0.528±0.110)g/L, (24.48±1.18) vs.(23.22±1.37), all P 0.05]. It is worth to pay close attention to the key discovery of this paper that HOMA-IR and Aβ1-42 levels were significantly lower and MoCA score was significantly higher in the linagliptin group than in the non-linagliptin group after 24 weeks of treatment(all P<0.05). Conclusions Linagliptin as one of DPP-4 enzyme inhibitors can improve the cognitive function in elderly patients with T2DM, which might be relevant to reducing serum Aβ level and improving HOMA-IR.DPP-4 enzyme inhibitor may be a good option for treatment of mild cognitive dysfunction in T2DM patients in the future. Key words: Diabetes mellitus, type 2; Cognitive impairment; Linagliptin; Amyloid β-protein

Combination Linagliptin and Empagliflozin Therapy Improves Diastolic Function in Female Diabetic db/db Mice

We recently reported that linagliptin (LINA) and empagliflozin (EMPA) monotherapies exhibit favorable effects in the heart, vasculature and kidneys in murine models of prediabetes and diabetes. Herein, we extend those studies by testing whether these two drugs used in combination improve diastolic function in diabetic female db/db mice. Eleven week old db/db mice were fed a diet containing LINA (2mg/kg/day) or EMPA (10mg/kg/day) monotherapy for 10 weeks (dbE10, dbL10). Additional groups received add-on therapy after 5 weeks on monotherapy (LINA added to EMPA (dbE10/L5) or EMPA added to LINA (dbL10/E5)). One group received LINA and EMPA combination therapy for the entire 10 week test period (dbL10/E10). One group was untreated (DbC). Glycemia, cardiac function, fibrosis and hypertrophy were examined by HbA1c, tissue Doppler ultrasound and histology. With the exception of LINA monotherapy, HbA1c was reduced in all other treated groups (p&amp;lt;0.05). Compared to lean mice on background strain (CkC), myocardial wall motion during diastole was impaired in untreated db/db mice, indicated by increased E/E’ ratio (LV filling pressure), and this was improved with mono- and add-on therapies. Myocardial fibrosis and hypertrophy were improved with mono- and add-on therapies. In summary, the combination of LINA and EMPA appeared to be as cardioprotective as monotherapies of each drug.# weeks on E or LType of therapyDiastolic FunctionGlycemiaCardiac RemodelingE, EMPA L, LINAE/E’ RatioHbA1c %Intersititial Fibrosis (AGSI)Cardiomyocyte cross sectional area (μm2)CkCuntreated18 ± 34.3 ± 0.2---368 ± 33DbCuntreated56 ± 3*11.0 ±0.6*4.9 ± 0.6533 ± 34†db E10mono38 ± 3*†5.9±0.2*†2.8 ± 0.2†433 ± 15†dbL10mono36 ± 2*†10.8±0.5*2.8 ± 0.2†411 ± 11†dbE10/L5L added to E35 ± 4*†6.5±0.2*†3.2 ± 0.2†421 ± 26†dbL10/E5E added to L34 ± 2*†6.9±0.3*†2.8 ± 0.1†358 ±12†dbL10/E10combo44 ± 6*†6.1±0.2*†3.2 ± 0.1†430 ± 21†*p&amp;lt;0.vs CkC †p&amp;lt;0.vs DbC Disclosure J. Habibi: None. A.R. Aroor: None. T. Klein: Employee; Self; Boehringer Ingelheim GmbH. E. Mayoux: None. V. DeMarco: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc..

Dipeptidyl Peptidase-4 Inhibition with Linagliptin Promotes Angiogenesis/Vasculogenesis in the Hearts of Female Diabetic db/db Mice

We have previously reported that the DPP-4 inhibitor linagliptin (LINA) prevents diastolic dysfunction and myocardial fibrosis in a mouse model of diet-induced obesity, a pre-clinical model of prediabetes. LINA suppressed WD-induced pro-inflammatory mediators, such as TRAF3IP2 and downstream signaling intermediates, NF-κB, AP-1 and p38-MAPK in the heart. Herein, we extend that study by testing whether LINA slows progression of diastolic dysfunction in diabetic db/db mice, and improves the underlying maladaptive immune/inflammatory response. To accomplish this, we fed db/db mice normal mouse chow with or without linagliptin (38 mg/kg chow). After performing echocardiography on mice treated or not for 10 weeks, we analyzed expression of 200 cytokines in myocardial extracts and performed Ingenuity Pathway Analysis (IPA) in an effort to determine what signaling pathways are predicted to be differentially activated in the heart. Mice treated with linagliptin had improved diastolic function indicated by lower LV filling pressure compared to untreated mice (E/E’; 35 vs. 50; p&amp;lt;0.05). IPA predicted that LINA activates pathways contributing to cardiovascular development of the vasculature (32 molecules, Activiation z-score = 3.7), angiogenesis (31 molecules, Activation z-score = 3.7) and vasculogenesis (27 molecules, Activation z-score = 3.7). Cardiomyocyte size (i.e., cross-sectional area) was reduced by 23% (533±30 vs. 411±18 μm2; p&amp;lt;0.05) and myocardial capillary density was two-fold higher with LINA treatment compared to untreated mice (p&amp;lt;0.05). In addition, the proteome analysis showed a significant decrease in TNF-α related apoptosis inducing ligand, a cytokine that induces endothelial nitric oxide, in untreated mice, however, this deficiency was prevented by LINA. These data suggest that linagliptin exerts a beneficial immune/inflammatory response in the diabetic heart that confers myocardial vasculoprotection. Disclosure R. Toedebusch: None. A.R. Aroor: None. J. Habibi: None. T. Klein: Employee; Self; Boehringer Ingelheim GmbH. L. Pulakat: None. V. DeMarco: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc..

Simultaneous spectrophotometric determination of compounds having relatively disparate absorbance and concentration ranges; application to antidiabetic formulation of linagliptin and metformin

The limited linear range of UV–Visible spectrophotometry may be insufficient to occupy multiple components with wide variations in their concentrations or absorptivities that will hinder the simultaneous spectrophotometric determination and may require spiking or measurements in subsequent dilution steps. The current work introduces the absorptivity target concentration (ATC) values, a simple way for the proper choice of the working spectral region to execute accurate and linear spectrophotometric measurements. Simultaneous spectrophotometric determination of linagliptin (LNG) and metformin (MET) that are present in a ratio of 1:400 was carried out using traditional spectrophotometric techniques such as third derivative and derivative ratio as well as recently developed techniques such as ratio difference and factorized dual wavelength. The proposed methods were able to determine MET in the concentration range of 50–1200 μg mL−1. On the other hand, LNG was successfully determined from its zero-order absorption UV-spectrum at λmax (296 nm) in the concentration range 2.5–25 μg mL−1. The mentioned methods were successfully applied for the determination of the LNG and MET in their combined dosage form. The methods were validated according to the ICH guidelines. The proposed ATC value can be employed as a novel concept for the proper choice of the working spectral region where spectrophotometric measurements can be deployed accurately and precisely.

A localized painfull rash induced by linagliptin in a patient with type 2 diabetes

A localized painfull rash induced by linagliptin in a patient with type 2 diabetes

Hypoglycemic Agents: Micro-Determination by Highly Sensitive and Validated Spectrophotometric Techniques

The objectives of our present study is to analyse the hypoglycemic agents, Linagliptin (LNG) and Alogliptin (ALG) in pure and bulk forms by simple, reproducible and highly sensitive spectrophotometric assays with detection at 530 (method A) and 520 nm (method B). The methods developed are based on the bleaching of above drugs with known excess of bromine. The unreacted bromine is determined based on its ability to bleach the dye Eriochrome blue black R (method A) and methyl red (method B) quantitatively at 530 (method A) and 520 nm (method B) for both the drugs obeying Beer’s law in the range, 0.0-10.0 and 0.0-8.0 μg ml-1 in both the methods A and B for LNG and ALG, respectively. The values of molar absorptivity were found to be 1.53 × 104 and 2.51 × 104 l mol-1 cm-1 in method A and 1.64 × 104 and 2.82 × 104 l mol-1 cm-1 in method B, respectively with the corresponding Sandell’s sensitivity values 0.0217 and 0.0188 μg cm-2 in method A and 0.0207 and 0.0167 μg cm-2 in method B. According to the current ICH guidelines, various validation parameters of proposed techniques were confirmed by applying the standard addition technique and the results were evaluated in terms of Student’s t-test and variance ratio F-test to find out the significance of proposed methods over the earlier reported methods.

SIMULTANEOUS DETERMINATION OF METFORMIN, LINAGLIPTIN IN JENTADUETO AND METFORMIN, SAXAGLIPTIN IN KOMBIGLYZE BY LC-MS METHOD

Objective: The objective of the present investigation was to develop a novel, simple and economic method for the determination of metformin (MET), linagliptin (LIN) and saxagliptin (SAX) in jentadueto and kombiglyze sample by employing the liquid chromatography and mass spectrometric method for estimation in bulk and pharmaceutical dosage form in presence of degradation products.Methods: The chromatographic separation was achieved by using the mobile phase composition of methanol and ammonium acetate buffer pH 4.5 (85:15 % v/v) on the Hypurity advance C-18 column at a flow rate of 0.5 ml/min. Ion signals m/z “130.10/70.10, 473.10/420.40 and 316.30/180.20” for metformin, linagliptin and saxagliptin respectively measured in positive ion mode. The detailed validation of the method was performed as per ICH guidelines.Results: The results of all validation parameters found within acceptance limits. The linearity of the drugs was found to be in the concentration range of 50–5000 ng/ml for all the drugs. Accuracy of the drugs was found to be from 94-102% and precision was found 4.67% RSD for all three drugs. The validated method was employed for the determination of drugs in the formulation and also determined the drugs in the presence of degradation products under stress conditions.Conclusion: The method was developed and validated as per guidelines. Hence, this method can be used for the simultaneous determination of metformin, linagliptin and metformin, saxagliptin in bulk and combined dosage forms.

Structural re-positioning, in silico molecular modelling, oxidative degradation, and biological screening of linagliptin as adenosine 3 receptor (ADORA3) modulators targeting hepatocellular carcinoma

Chemical entities with structural diversity were introduced as candidates targeting adenosine receptor with different clinical activities, containing 3,7-dihydro-1H-purine-2,6-dione, especially adenosine 3 receptors (ADORA3). Our initial approach started with pharmacophore screening of ADORA3 modulators; to choose linagliptin (LIN), approved anti-diabetic drug as Dipeptidyl peptidase-4 inhibitors, to be studied for its modulating effect towards ADORA3. This was followed by generation, purification, analytical method development, and structural elucidation of oxidative degraded product (DEG). Both of LIN and DEG showed inhibitory profile against hepatocellular carcinoma cell lines with induction of apoptosis at G2/M phase with increase in caspase-3 levels, accompanied by a downregulation in gene and protein expression levels of ADORA3 with a subsequent increase in cAMP. Quantitative in vitro assessment of LIN binding affinity against ADORA3 was also performed to exhibit inhibitory profile at Ki of 37.7 nM. In silico molecular modelling showing binding affinity of LIN and DEG towards ADORA3 was conducted.

CHARACTERIZATION OF LINAGLIPTIN USING ANALYTICAL TECHNIQUES

Linagliptin (LGT) is a member of the class of gliptins that inhibit the enzyme dipeptidyl-peptidase-4. They are used to reduce glucose blood levels in patients with type 2 Diabetes mellitus. Due to its recent development and launching on the market, LGT has no official compendium monograph, national or international, or available registries for the qualitative determination of this drug. The objective of this work was to characterize LGT by using thermal techniques, nuclear magnetic resonance, mass and infrared spectrometry, liquid chromatography and ultraviolet spectrophotometry to be used as a chemical reference substance. The range and melting point obtained are in accordance with that described in the literature. The main groups of LGT molecule were observed in infrared spectroscopy and the molecular ion m/z 473.25 ratio was found in mass spectroscopy analysis. In UV spectroscopy, the maximum wavelength absorption of the substance in different solvents can be observed. The chromatographic methods provide selectivity for LGT and can be used to analyze it qualitatively. The proposed conditions have been successfully applied for identification and qualitative analysis of LGT as a chemical reference substance, contributing to studies of this gliptin, and to the quality control of medicines that contain it.

New LC–UV methods for pharmaceutical analysis of novel anti-diabetic combinations

New, simple, selective, and sensitive liquid chromatography–ultraviolet (LC–UV) methods have been developed and subsequently validated for simultaneous determination of linagliptin–empagliflozin combination and simultaneous determination of alogliptin benzoate–pioglitazone hydrochloride combination. Linearity was found to be acceptable over the concentration ranges of 2–50 μg mL−1, 4–100 μg mL−1, 0.5–25 μg mL−1, and 1–25 μg mL−1 for linagliptin (LNG), empagliflozin (EMG), alogliptin (ALG), and pioglitazone (PGN), respectively. All the methods were applied successfully to the analysis of the pharmaceutical dosage forms. The optimized methods were validated and proved to be robust and accurate for the quality control of the mentioned drugs in their different pharmaceutical dosage forms.

Time to exacerbation of heart failure is longer in Malaysian population on dipeptidyl peptidase-4 inhibitor

Context: Diabetes mellitus is a recognized risk factor for heart failure. Dipeptidyl peptidase-4 inhibitors (DPP4i) are used in patients with diabetes largely due to its efficacy in glycated hemoglobin (HbA1c) reduction, neutral weight effect, and lower hypoglycemic events. New antidiabetic medications such as the glitazones have been linked with increasing mortality and heart failure exacerbations. The effect of DPP4i in heart failure has not been shown in a heterogenous Asian population. Aims: The aim of this study was to assess incidence of heart failure and cardiovascular (CV) events in patients with diabetes with known coronary artery disease (CAD) treated with DPP4i. Subjects and Methods: This was a single-center, retrospective analysis of patients with diabetes mellitus attending various specialist clinics in Universiti Teknologi MARA treated with available DPP4i agents from January 2013 to July 2015. Medical records were reviewed and data collected for demographic, anthropometric, laboratory, and treatment modalities. Endpoints include changes in body weight, body mass index, lipid, renal profile, and CV events during follow-up. Results: Three hundred and twenty-three patients with diabetes were screened and 307 fulfilled the inclusion criteria. Fifty-four were on linagliptin, 115 were on vildagliptin, and 154 were on saxagliptin. Majority of patients (87.6%) had uncontrolled diabetes at baseline (HbA1c, %) (8.9 ± 2.07). There was a significant reduction in HbA1c from baseline to visit 1 at 3 months (P = 0.000). Similarly, significant improvement in HbA1c seen from baseline to visit 1 (P = 0.000). A higher CV event rate was found between 20 and 30 weeks of therapy with DPP4i. The cumulative survival was 99.5% at 20 weeks and reduced to 98.75% at 30 weeks (P = 0.033). There were seven reported events (0.98%) due to heart failure or acute coronary syndrome. These participants had higher baseline HbA1c and creatinine compared to the overall cohort. Conclusions: Higher CV events were seen in diabetic patients with known CAD treated with DPP4i between 20 and 30 weeks of therapy and occurred earlier in patients with chronic kidney disease. This is later than published data and raises the need to monitor this group of patients for symptoms of heart failure beyond conventional monitoring.

Development of RP-HPLC, Stability Indicating Method for Degradation Products of Linagliptin in Presence of Metformin HCl by Applying 2 Level Factorial Design; and Identification of Impurity-VII, VIII and IX and Synthesis of Impurity-VII.

The novel reverse phase-high performance liquid chromatography (RP-HPLC), stability indicating method was developed for determination of linagliptin (LGP) and its related substances in linagliptin and metformin HCl (MET HCl) tablets by implementing design of experiment to understand the critical method parameters and their relation with critical method attributes; to ensure robustness of the method. The separation of nine specified impurities was achieved with a Zorbax SB-Aq 250 × 4.6 mm, 5 µm column, using gradient elution and a detector wavelength of 225 nm, and validated in accordance with International Conference on Harmonization (ICH) guidelines and found to be accurate, precise, reproducible, robust, and specific. The drug was found to be degrading extensively in heat, humidity, basic, and oxidation conditions and was forming degradation products during stability studies. After slight modification in the buffer and the column, the same method was used for liquid chromatography–mass spectrometry (LC-MS) and ultra-performance liquid chromatography -time-of-flight/mass spectrometry UPLC-TOF/MS analysis, to identify m/z and fragmentation of maximum unspecified degradation products i.e., Impurity-VII (7), Impurity-VIII (8), and Impurity-IX (9) formed during stability studies. Based on the results, a degradation pathway for the drug has been proposed and synthesis of Impurity-VII (7) is also discussed to ensure an in-depth understanding of LGP and its related degradation products and optimum performance during the lifetime of the product.

Clinical effect of Linagliptin on treating type 2 diabetic patients with early diabetic kidney disease

Objective To assess the clinical effect of Linagliptin on treating type 2 diabetic patients with early diabetic kidney disease. Methods Fifty cases type 2 diabetes patients with early diabetic kidney disease were selected and randomly divided into two groups.All patients carried out diabetes education, strict diet therapy, and proper exercise.Twenty-six cases patients were enrolled in Linagliptin group, oral Linagliptin 5 mg, 1 times/d.Twenty-four cases patients were enrolled in Gliclazide group, oral Gliclazide 30 mg, 1 times/d, and monitored the blood sugar to adjust drug dosage, the maximum dose of 60 mg, 1 times/d.The observation time of both groups was six months.The glycosylated hemoglobin(HbA1c) and urinary albumin-to-creatinine ratio(UACR) of two groups were compared before and after treatment. Results The level of HbA1c in Linagliptin group after treatment was lower than before treatment, the difference was significant((7.39±0.37)% vs.(8.30±0.48)%, t=14.232, P<0.001). The level of HbA1c in Gliclazide group after treatment was lower than before treatment, the difference was significant((7.45±0.41)% vs.(8.38±0.49)%, t=23.146, P<0.001). There was no significant difference on the level of HbA1c between the two groups after treatment(t=-0.517, P=0.608). The level of UACR in Linagliptin group after treatment was lower than before treatment, the difference was significant((83.64±37.44) mg/g vs.(109.56±53.36) mg/g, t=4.632, P<0.001). The level of UACR in Gliclazide group after treatment was lower than before treatment, the difference was significant((93.58±47.17) mg/g vs.(103.77±48.80) mg/g, t=2.909, P=0.008). There was significant difference on the level of UACR between the two groups after treatment(t=-2.172, P=0.035). Conclusion Linagliptin is a kind of effective and safe regent, can be used in patients with type 2 diabetes and early diabetic kidney disease. Key words: Linagliptin; Type 2 diabetes; Diabetic kidney disease; Urinary albumin-to-creatinine ratio