Identification of Risk Factors for Gliptin-associated Bullous Pemphigoid among Diabetic Patients.

Drug-associated bullous pemphigoid has been shown to follow long-term gliptin (dipeptidyl-peptidase 4 inhibitors) intake. This study aimed at identifying risk factors for gliptin-associated bullous pemphigoid among patients with type 2 diabetes. A retrospective study was conducted in a tertiary centre among diabetic patients exposed to gliptins between the years 2008-2021. Data including demographics, comorbidities, medications, and laboratory results were collected using the MDClone platform. Seventy-six patients with type 2 diabetes treated with dipeptidyl-peptidase 4 inhibitors who subsequently developed bullous pemphigoid were compared with a cohort of 8,060 diabetic patients exposed to dipeptidyl-peptidase 4 inhibitors who did not develop bullous pemphigoid. Based on a multivariable analysis adjusted for age and other covariates, Alzheimer's disease and other dementias were significantly more prevalent in patients with bullous pemphigoid (p = 0.0013). Concomitant use of either thiazide or loop diuretics and gliptin therapy was associated with drug-associated bullous pemphigoid (p < 0.0001 for both). While compared with sitagliptin, exposure to linagliptin and vildagliptin were associated with bullous pemphigoid with an odds ratio of 5.68 and 6.61 (p < 0.0001 for both), respectively. These results suggest gliptins should be prescribed with caution to patients with type 2 diabetes with coexisting Alzheimer's and other dementias, or patients receiving long-term use of thiazides and loop diuretics. The use of sitagliptin over linagliptin and vildagliptin should be preferred in these patients.

Identification and Structural Characterization of Degradation Products of Linagliptin by Mass Spectrometry Techniques.

As part of the development and production of pharmaceuticals, the purity of Active Pharmaceutical Ingredients stands as a fundamental parameter that significantly influences the quality, safety, and efficacy of the final drug product. Impurities in Active Pharmaceutical Ingredients are various unwanted substances that can appear during the whole manufacturing process, from raw materials to the final product. These impurities can stem from multiple sources, including starting materials, intermediates, reagents, solvents, and even degradation products resulting from exposure to environmental factors such as heat, light, or moisture. Their presence can potentially compromise the therapeutic effect of the drug, introduce unexpected side effects, or even pose safety risks to patients. This study aims to conduct the forced degradation of linagliptin and subsequently attempt to identify the resulting degradants. The degradation procedures were carried out in accordance with the guidelines of the International Committee for Harmonization. The degradation profile of linagliptin was investigated under various conditions, including acid hydrolysis, alkaline hydrolysis, oxidation, heat, and light exposure, utilizing ultra-performance liquid chromatography connected to a photo array detector. Identification and characterization of the degradation products were achieved using an ultra-performance liquid chromatography coupled with a single quadrupole detector mass spectrometer and also a liquid chromatography coupled with a high-resolution mass spectrometry. The identified degradation products demonstrate that linagliptin is particularly susceptible to degradation when exposed to acid and peroxide. Whereas, no significant degradation effects were observed under alkali, thermolytic, and photolytic conditions.

Acute and Chronic Exposure to Linagliptin, a Selective Inhibitor of Dipeptidyl Peptidase-4 (DPP-4), Has an Effect on Dopamine, Serotonin and Noradrenaline Level in the Striatum and Hippocampus of Rats.

Linagliptin is a selective dipeptidyl peptidase-4 (DPP-4) inhibitor that indirectly elevates the glucagon-like peptide-1 (GLP-1) level. The aim of the present study was to check whether linagliptin has an influence on neurotransmission in rat brain. Rats were acutely and chronically exposed to linagliptin (10 and 20 mg/kg, intraperitoneally (i.p.)). Twenty-four hours later, the striatum and hippocampus were selected for further studies. In neurochemical experiments, using high-performance liquid chromatography with electrochemical detection (HPLC-ED), the concentrations of three major neurotransmitters-dopamine, serotonin and noradrenaline-and their metabolites were measured. The analysis of mRNA expression of dopamine (D1 and D2), serotonin (5-HT-1 and 5-HT-2) and noradrenaline (α1 and α2a) receptors was also investigated using real-time quantitative reverse transcription polymerase chain reaction (RQ-PCR) in the same brain areas. Linagliptin has the ability to influence the dopaminergic system. In the striatum, the elevation of dopamine and its metabolites was observed after repeated administration of that linagliptin, and in the hippocampus, a reduction in dopamine metabolism was demonstrated. Acute linagliptin exposure increases the serotonin level in both areas, while after chronic linagliptin administration a tendency for the mRNA expression of serotoninergic receptors (5-HT1A and 5-HT2A) to increase was observed. A single instance of exposure to linagliptin significantly modified the noradrenaline level in the striatum and intensified noradrenaline turnover in the hippocampus. The recognition of the interactions in the brain between DPP-4 inhibitors and neurotransmitters and/or receptors is a crucial step for finding novel discoveries in the pharmacology of DPP-4 inhibitors and raises hope for further applications of DPP-4 inhibitors in clinical practices.

Comparative evaluation of physical and chemical enhancement techniques for transdermal delivery of linagliptin.

Linagliptin is a dipeptidyl peptidase-4 inhibitor used for the management of type-2 diabetes. US FDA-approved products are available exclusively as oral tablets. The inherent drawbacks of the oral administration route necessitate exploring delivery strategies via other routes. In this study, we investigated the feasibility of transdermal administration of linagliptin through various approaches. We compared chemical penetration enhancers (oleic acid, oleyl alcohol, and isopropyl myristate) and physical enhancement techniques (iontophoresis, sonophoresis, microneedles, laser, and microdermabrasion) to understand their potential to improve transdermal delivery of linagliptin. To our knowledge, this is the first reported comparison of chemical and physical enhancement techniques for the transdermal delivery of a moderately lipophilic molecule. All physical enhancement techniques caused a significant reduction in the transepithelial electrical resistance of the skin samples. Disruption of the skin's structure post-treatment with physical enhancement techniques was further confirmed using characterization techniques such as dye binding, histology, and confocal microscopy. In vitro permeation testing (IVPT) demonstrated that the passive delivery of linagliptin across the skin was < 5 µg/sq.cm. Two penetration enhancers - oleic acid (93.39 ± 8.34 µg/sq.cm.) and oleyl alcohol (424.73 ± 42.86 µg/sq.cm.), and three physical techniques - iontophoresis (53.05 ± 0.79 µg/sq.cm.), sonophoresis (141.13 ± 34.22 µg/sq.cm.), and laser (555.11 ± 78.97 µg/sq.cm.) exceeded the desired target delivery for therapeutic effect. This study established that linagliptin is an excellent candidate for transdermal delivery and thoroughly compared chemical penetration and physical transdermal delivery strategies.

Exploring the modulatory effects of sotagliflozin on dyslipidemia in mice: The role of glucagon, fibroblast growth factor 21 and glucagon-like peptide 1.

Sotagliflozin is the first dual SGLT1/2 inhibitor antidiabetic drug approved by the US Food and Drug Administration for the management of heart failure. SGLT1/2 inhibition is observed to potentiate the secretion of the incretin hormone, glucagon-like peptide-1 (GLP-1). The current preclinical research sought to investigate the effect of sotagliflozin on the secretion of fat-regulating peptides such as GLP-1, glucagon and fibroblast growth factor 21 (FGF21) and their prospective association with sotagliflozin's potential beneficial effects on dyslipidaemia. During an oral fat tolerance test in mice, sotagliflozin substantially increased GLP-1 and insulin concentrations. Although sotagliflozin alone did not ameliorate postprandial lipemia, its combination with linagliptin (DPP-IV inhibitor) significantly improved lipid tolerance comparable to orlistat (lipase inhibitor). In a triton-induced hypertriglyceridemia model, sotagliflozin, along with other medications (fenofibrate, exenatide and linagliptin) reduced fat excursion; however, co-administration with linagliptin provided no extra advantage. Furthermore, sotagliflozin stimulated glucagon secretion in the alpha TC1.6 cells and healthy mice, which resulted in an increased circulating FGF21 and ß-hydroxybutyrate concentration. Finally, chronic treatment of sotagliflozin in high-fat diet (HFD)-fed obese mice resulted in reduced body weight gain, liver triglyceride, cholesterol, interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-α) levels compared with the placebo group. However, the addition of linagliptin did not provide any additional benefit. In conclusion, sotagliflozin was found to have an effect on GLP-1 and also stimulate the release of glucagon and FGF21, which are important for regulating fat metabolism. Therefore, sotagliflozin might represent a potential therapeutic approach for the treatment of diabetic dyslipidemia and steatohepatitis.

Network-based drug repositioning of linagliptin as a potential agent for uterine fibroids targeting transforming growth factor-beta mediated fibrosis.

Uterine fibroid is the most common non-cancerous tumor with no satisfactory options for long-term pharmacological treatment. Fibroblast activation protein-α (FAP) is one of the critical enzymes that enhances the fibrosis in uterine fibroids. Through STITCH database mining, we found that dipeptidyl peptidase-4 inhibitors (DPP4i) have the potential to inhibit the activity of FAP. Both DPP4 and FAP belong to the dipeptidyl peptidase family and share a similar catalytic domain. Hence, ligands which have a binding affinity with DPP4 could also bind with FAP. Among the DPP4i, linagliptin exhibited the highest binding affinity (Dock score = -8.562 kcal/mol) with FAP. Our study uncovered that the differences in the S2 extensive-subsite residues between DPP4 and FAP could serve as a basis for designing selective inhibitors specifically targeting FAP. Furthermore, in a dynamic environment, linagliptin was able to destabilize the dimerization interface of FAP, resulting in potential inhibition of its biological activity. True to the in-silico results, linagliptin reduced the fibrotic process in estrogen and progesterone-induced fibrosis in rat uterus. Furthermore, linagliptin reduced the gene expression of transforming growth factor-ß (TGF-ß), a critical factor in collagen secretion and fibrotic process. Masson trichrome staining confirmed that the anti-fibrotic effects of linagliptin were due to its ability to reduce collagen deposition in rat uterus. Altogether, our research proposes that linagliptin has the potential to be repurposed for the treatment of uterine fibroids.

Two cases of linagliptin-associated bullous pemphigoid resulting in sepsis and endocarditis.

We describe two patients, in their 70s, each presenting to the emergency department, with 6-week histories of progressively developing pruritic bullae. Both individuals had multiple comorbidities, including type 2 diabetes-for which they took linagliptin, chronic kidney disease, hypertension and prosthetic heart valves. Owing to systemic illness and endocarditis secondary to superadded bacterial infections, they both required intensive treatment and prolonged hospital admissions.Despite the beneficial effect of linagliptin on glycaemic control and its reported cardiovascular and renal safety profiles, we add our cases as evidence of the significant risk of developing bullous pemphigoid while taking this medication. Secondary infection of bullous pemphigoid increased the risk of developing endocarditis, particularly among individuals with a medical history of valve replacement surgery. Considering this, we advocate caution when prescribing this medication.

Linagliptin, a DPP-4 inhibitor, activates AMPK/FOXO3a and suppresses NFκB to mitigate the debilitating effects of diethylnitrosamine exposure in rat liver: Novel mechanistic insights.

Accumulating evidence suggests that dysregulation of FOXO3a plays a significant role in the progression of various malignancies, including hepatocellular carcinoma (HCC). FOXO3a inactivation, driven by oncogenic stimuli, can lead to abnormal cell growth, suppression of apoptosis, and resistance to anticancer drugs. Therefore, FOXO3a emerges as a potential molecular target for the development of innovative treatments in the era of oncology. Linagliptin (LNGTN), a DPP-4 inhibitor known for its safe profile, has exhibited noteworthy anti-inflammatory and anti-oxidative properties in previous in vivo studies. Several potential molecular mechanisms have been proposed to explain these effects. However, the capacity of LNGTN to activate FOXO3a through AMPK activation has not been investigated. In our investigation, we examined the potential repurposing of LNGTN as a hepatoprotective agent against diethylnitrosamine (DENA) intoxication. Additionally, we assessed LNGTN's impact on apoptosis and autophagy. Following a 10-week administration of DENA, the liver underwent damage marked by inflammation and early neoplastic alterations. Our study presents the first experimental evidence demonstrating that LNGTN can reinstate the aberrantly regulated FOXO3a activity by elevating the nuclear fraction of FOXO3a in comparison to the cytosolic fraction, subsequent to AMPK activation. Moreover, noteworthy inactivation of NFκB induced by LNGTN was observed. These effects culminated in the initiation of apoptosis, the activation of autophagy, and the manifestation of anti-inflammatory, antiproliferative, and antiangiogenic outcomes. These effects were concomitant with improved liver function and microstructure. In conclusion, our findings open new avenues for the development of novel therapeutic strategies targeting the AMPK/FOXO3a signaling pathway in the management of chronic liver damage.

Development of eco-friendly spectrophotometric methods for analysis of metformin hydrochloride and linagliptin in presence of metformin toxic impurity in their pure and dosage forms: Validation, practicality and greenness studies.

Metformin is considered as type 2 diabetes first line treatment according to American Diabetes Association and European Association. But, in some cases, di- or tri - therapy should be prescribed for glycemic management, prevention of the maximum dose side effects and induced effectiveness. Co-administration of Linagliptin with metformin has many benefits on diabetic patients such as decrease the possibility of hypoglycemia. For the first time, novel and reliable techniques were developed and verified for the concurrent quantification of metformin hydrochloride and linagliptin, while accounting for the existence of metformin toxic impurity 1-cyanoguanidine in their pure and dosage forms. Method (A) utilizes the zero-order spectrophotometric approach to quantitatively determine the concentration of linagliptin. The measurements are performed at a wavelength of 295 nm. The double divisor derivative ratio spectrophotometric method is used in Method (B) to measure the amounts of metformin and cyanoguanidine at 252 nm and 219 nm wavelengths, respectively. The spectrophotometric method (C) for determining metformin and cyanoguanidine at 252 nm and 223 nm, respectively, is based on the single divisor derivative ratio-zero crossing technique. The obtained findings were subjected to statistical comparison with the reported method, revealing no statistically significant differences. The Green Analytical Procedure Index (GAPI) and Analytical GREEnness Metric approach (AGREE) determined that these approaches had a high degree of environmental friendliness. Additionally, the proposed strategy was deemed to be practical according to the Blue Applicability Grade Index (BAGI) assessment tool.

Hypoglycemia and Cardiovascular Outcomes in the CARMELINA and CAROLINA Trials of Linagliptin: A Secondary Analysis of Randomized Clinical Trials.

Importance: Previous studies have reported an association between hypoglycemia and cardiovascular (CV) events in people with type 2 diabetes (T2D), but it is unclear if this association is causal or identifies a high-risk patient phenotype. Objective: To evaluate the associations between hypoglycemia and CV outcomes. Design, Setting, and Participants: This secondary analysis was a post hoc assessment of the multinational, double-blind CARMELINA (Cardiovascular and Renal Microvascular Outcome Study With Linagliptin; 2013-2016) and CAROLINA (Cardiovascular Outcome Trial of Linagliptin vs Glimepiride in Type 2 Diabetes; 2010-2018) randomized clinical trials of the antihyperglycemic drug, linagliptin, a dipeptidyl peptidase 4 inhibitor. Participants were adults with T2D at high CV risk with or without high kidney risk. By design, participants in the CARMELINA trial had longer duration of T2D and had a higher CV risk than participants in the CAROLINA trial. Data analyses were conducted between June 2021 and June 2023. Intervention: Linagliptin or placebo in the CARMELINA trial, and linagliptin or glimepiride in the CAROLINA trial. Main Outcomes and Measures: The primary outcome for both trials was CV death, myocardial infarction (MI), or stroke (3-point major adverse CV events [3P-MACE]). For the present analyses, hospitalization for heart failure (HF) was added. Hypoglycemia was defined as plasma glucose less than 54 mg/dL or severe hypoglycemia (episodes requiring the assistance of another person). Associations between the first hypoglycemic episode and subsequent CV events and between nonfatal CV events (MI, stroke, hospitalization for HF) and subsequent hypoglycemic episodes were assessed using multivariable Cox proportional hazards regression models. Sensitivity analyses explored the risk of CV events within 60 days after each hypoglycemic episode. Results: In the CARMELINA trial (6979 patients; 4390 males [62.9%]; mean [SD] age, 65.9 [9.1] years), there was an association between hypoglycemia and subsequent 3P-MACE plus hospitalization for HF (hazard ratio [HR], 1.23; 95% CI, 1.04-1.46) as well as between nonfatal CV events and subsequent hypoglycemia (HR, 1.39; 95% CI, 1.06-1.83). In the CAROLINA trial (6033 patients; 3619 males (60.0%); mean [SD] age, 64.0 [9.5] years), there was no association between hypoglycemia and subsequent 3P-MACE plus hospitalization for HF (HR, 1.00; 95% CI, 0.76-1.32) and between nonfatal CV events and subsequent hypoglycemia (HR, 1.44; 95% CI, 0.96-2.16). In analyses of CV events occurring within 60 days after hypoglycemia, there was either no association or too few events to analyze. Conclusions and Relevance: This study found bidirectional associations between hypoglycemia and CV outcomes in the CARMELINA trial but no associations in either direction in the CAROLINA trial, challenging the notion that hypoglycemia causes adverse CV events. The findings from the CARMELINA trial suggest that both hypoglycemia and CV events more likely identify patients at high risk for both. Trial Registration: ClinicalTrials.gov Identifier: NCT01897532 (CARMELINA) and NCT01243424 (CAROLINA).

DPP-4 inhibition by linagliptin ameliorates age-related mild cognitive impairment by regulating microglia polarization in mice.

Extensive preclinical evidence demonstrates a causative link between insulin signaling dysfunction and the pathogenesis of Alzheimer's disease (AD), and diabetic drugs may represent a promising approach to fighting AD. However, it remains to be determined which antidiabetic drugs are more effective in preventing cognitive impairment. Thus, the present study investigated the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin on cognitive impairment in middle-aged mice by comparing it with the effect of metformin. We found that DPP-4 activity increased in the hippocampus of middle-aged mice, and DPP-4 was mainly expressed by microglia rather than astrocytes and oligodendrocytes. DPP-4 directly regulated M1/M2 microglia polarization following LPS or IL-4 stimulation, while DPP-4 inhibitor, linagliptin, suppressed M1-polarized activation and induced M2-polarized activation. Both linagliptin and metformin enhanced cognitive ability, increased hippocampal synaptic plasticity and neurogenesis, and decreased age-related oxidative stress and inflammation by regulating microglia polarization in the hippocampus of middle-aged mice. The combination of linagliptin and metformin showed a maximum protective effect compared to the individual drugs alone. Loss of macrophage inflammatory protein-1α (MIP-1α), a DPP-4 substrate, abrogated the cognitive protection and anti-inflammation effects of linagliptin. Therefore, the current investigation exhibits a potential utility for DPP-4 inhibition in attenuating microglia-mediated inflammation and preventing mild cognitive impairment (MCI) in middle-aged mice, and the effect was partly mediated by MIP-1α.

Gliptin-induced bullous pemphigoid.

OBJECTIVES: Bullous pemphigoid (BP) is a rare, autoimmune, blistering disease in elderly patients that can be triggered by external factors including drugs. Drug-induced bullous pemphigoid (DIBP) does not always follow a self-limiting course after the withdrawal of the offending drug. Dipeptidyl peptidase-4 (DPP-4) inhibitors or gliptins seem to be associated with a significant risk of inducing BP. CASE PRESENTATION: We report 2 cases of BP attributed to the DPP-4 inhibitor linagliptin. In both cases, the clinical manifestation was strongly suggestive of BP. The diagnosis was verified by histology and direct immunofluorescence (DIF). Linagliptin and all other possible drug triggers of BP were discontinued after consultation with an endocrinologist and a cardiologist. Systemic treatment of BP consisted of methylprednisolone and tetracycline. During the follow-up period, one of the patients suffered a fatal brain stroke while the other was managed with reduced doses of corticosteroids. CONCLUSION: The proper management of autoimmune bullous skin disorders in elderly patients includes a scrupulous assessment of plausible drug triggers. Systemic corticosteroids for treating severe cases of DIBP can worsen concomitant diseases which often necessitates multidisciplinary care.

Development of sensitive spectrofluorometric approach based on formation of pyrrolidone derivative for determination of linagliptin through condensation reaction with ninhydrin and phenylacetaldehyde: Application to content uniformity and real plasma.

The new drug linagliptin belongs to the class of dipeptidyl peptidase-4 enzyme inhibitors. Linagliptin is used to treat type 2 diabetes and is taken orally either alone or in combination with other drugs. In this instance, a new, simple, and economical technique for analyzing linagliptin was developed by the effective use of a pyrrolidone derivative. The primary amine group of linagliptin permits its condensation with ninhydrin (0.14% w/v) to produce a fluorescent product in the presence of phenylacetaldehyde (0.02% v/v). All experimental parameters were carefully examined and adjusted in order to monitor the generation of the pyrrolidone derivative at excitation and emission wavelengths of 385 and 475 nm, respectively. The calibration graph was made by plotting the intensity of the fluorescence in relation to linagliptin concentration. A significant linearity was found for values ranging from 20 to 460 ng/mL. The process's validity has been verified by a thorough assessment of the instructions provided by the International Conference on Harmonization (ICH). The results indicate excellent uniformity with a reference method, showing that there is no substantial difference in precision and accuracy. The proposed approach was utilized for determining linagliptin in real rat plasma successfully owing to its high sensitivity. Additionally, the proposed approach was evaluated using the Eco-Scale evaluation tool and showed a high degree of eco-friendliness (86/100).

Development and validation of Empagliflozin and Linagliptin simultaneous estimation in rat plasma using freezing lipid precipitation and SCX-SPE assisted HPLC-MS/MS method and its application in pharmacokinetic studies.

A quick and sensitive liquid chromatography-mass spectrometry technique was designed, improved, and validated for simultaneous determination of Empagliflozin (EPG) and Linagliptin (LNG) using Empagliflozin-d4 (EPG-d4) and linagliptin-d4 (LNG-d4) as internal standards (IS) in rat plasma. Target analytes and the IS were extracted using freezing lipid precipitation (FLP) and optimized using the strong cation exchange solid phase extraction (SCX-SPE) method to achieve the maximum sample clean-up. In particular, when combined with SPE clean-up, FLP can efficiently eliminate the plasma sample's high lipid content. More than 84.14% of plasma lipids were rapidly removed during the FLP procedure, with minimal loss of EPG and LNG. We used LC-atmospheric chemical ionization (APCI)-mass spectrometry was employed to assess the efficiency of FLP in lipid removal. The SCX-SPE cartridges removed the remaining impurities from EPG and LNG, allowing for further purification. The samples were chromatographically separated using a Spherisorb RP/Cyano column by pumping a gradient mobile phase comprised of acetonitrile and 25 mM ammonium acetate buffer (pH 8.1) in positive ion mode at a flow rate of 0.8 mL/min. The selected reaction monitoring technique was performed using a Waters triple-stage quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) source. The chromatographic separation was accomplished using a Waters Acquity® high-performance liquid chromatography (HPLC) system. Mass transition (m/z) of 451.15/71.12 for EPG, m/z 473.27/419.94 for LNG; m/z 455.19/71.12 for EPG-d4, and 477.27/423.94 for LNG-d4 was successfully achieved. This study successfully examined the concentration ranges of 25-1050 ng/mL for EPG and 0.35-15 ng/mL for LNG. The results showed that the linearity of EPG ranged from 25.14 to 985.26 ng/mL, while the linearity of LNG ranged from 0.59 to 14.86 ng/mL. The relative standard deviation (RSD) for both EPG and LNG, within and between days, were below 3.83%, indicating that they fall within acceptable limits. This novel approach demonstrated favourable outcomes in a pharmacokinetic study involving healthy rats, where EPG and LNG were co-administered. This study found that the co-administration of both drugs did not have a significant impact on their pharmacokinetic behavior, suggesting the absence of any drug-drug interactions.

Pylorus ligation-induced hyperacidity: synergistic prophylactic effects of linagliptin and L-arginine via up-regulation of EP4 receptor subtype and improvement of vascular endothelial damage.

Gastric hyperacidity and ulceration are chronic diseases characterized by repeated healing followed by re-exacerbation. The study aims to protect against gastric hyperacidity without interfering with gastric acid secretion. Pylorus ligation-induced hyperacidity is commonly utilized in the induction of gastric ulcers.Forty-two rats were distributed into seven groups (n = 6). Group I comprised sham-operated group. Group II served as pylorus-ligation group. Groups III-VII were given oral Linagliptin (LN; 3 and 6 mg/kg), L-arginine (LA; 150 and 300 mg/kg) and their combination (LN 3 + LA 150 mg/kg), respectively for 7 days. On the 8th day, groups II-VII were subjected to pylorus-ligation.Treatment of pylorus-ligated rats with LN, LA and their combination improved the gastric hyperacidity as exhibited by a marked reduction in the gastric juice volume, total and free acidities and pepsin contents with a noticeable increase in pH. Pre-treatment with LN, LA and their combination showed a marked alleviation in the gastric inflammatory indicators evidenced by reduction in the gastric levels of MCP-1and Il-1ß as well as elevation of eNOS levels versus the sham-operated group. A marked up-regulation in the gastric gene expression of PGE, EP4 and VEGF accompanied by an improvement of the histopathologic pictures/scores, and TNF-α and caspase-3 immuno-staining were also recorded.By estimating the combination-index, it can be concluded that combining LN with LA exhibited prophylactic synergistic effects in ameliorating pylorus ligated-induced hyperacidity, mainly via up-regulation of EP4 receptor and improvement of vascular endothelial damage through VEGF expression in gastric mucosa.

A Quantitative Systems Pharmacology Model of the Incretin Hormones GIP and GLP1, Glucagon, Glucose, Insulin, and the Small Molecule DPP-4 Inhibitor, Linagliptin.

In the current study, we established a comprehensive quantitative systems pharmacology (QSP) model using linagliptin as the model drug, where drug disposition, drug intervention on dipeptidyl peptidase-4 (DPP-4), glucose-dependent insulinotropic peptide (GIP), Glucagon-like peptide-1 (GLP-1), glucagon, glucose, and insulin are integrated together with the cross talk and feedback loops incorporated among the whole glycemic control system. In the final linagliptin QSP model, the complicated disposition of linagliptin was characterized by a 2-compartment pharmacokinetic (PK) model with an enterohepatic cycling (EHC) component as well as target-mediated drug disposition (TMDD) processes occurring in both tissues and plasma, and the inhibitory effect of linagliptin on DPP-4 was determined by the linagliptin-DPP-4 complex in the central compartment based on target occupancy principle. The integrated GIP-GLP1-glucagon-glucose-insulin system contains five indirect response models as the "skeleton" structure with 12 feedback loops incorporated within the glucose control system. Our model adequately characterized the substantial nonlinear PK of linagliptin, time course of DPP-4 inhibition, as well as the kinetics of GIP, GLP-1, glucagon, and glucose simultaneously in humans. Our model provided valuable insights on linagliptin pharmacokinetics/pharmacodynamics and complicated glucose homeostasis. Since the glucose regulation modeling framework within the QSP model is "drug-independent", our model can be easily adopted by others to evaluate the effect of other DPP-4 inhibitors on the glucose control system. In addition, our QSP model, which contains more components than other reported glucose regulation models, can potentially be used to evaluate the effect of combination antidiabetic therapy targeting different components of glucose control system.

Cubosomal functionalized block copolymer platform for dual delivery of linagliptin and empagliflozin: Recent advances in synergistic strategies for maximizing control of high-risk type II diabetes.

A well-made chitosan-PVP block copolymer platform was equipped with highly ordered and uniform nano-channels. This highly adhesive block copolymer platform was designed to ensure the efficient co-delivery of two synergistic-acting hypoglycemic drugs. Linagliptin oral bioavailability is 30% due to poor permeability and intestinal degradation. Its pharmacokinetics shows a non-linear profile. Empagliflozin exhibited decreased permeability and decreased solubility in aqueous media between pH 1 and 7.5. Cubosomes were functionalized as a good microdomain to guest and improve the physicochemical characteristics of drug molecules with decreased permeability and solubility. Cubosomes loaded with linagliptin (linagliptin cubosomes (LCs)) and empagliflozin (empagliflozin cubosomes ECs) were separately prepared using the top-down method and optimized by applying 23 factorial design. Optimized cubosomal systems LCs (F3) and ECs (F4) were incorporated into a chitosan-PVP gel to obtain dual cubosome-loaded platforms (LECF) optimized through 22 factorial design. The permeation study from the optimized LECF (C1) ensured enhanced empagliflozin permeation alongside continued efflux for linagliptin, resolving potential risks due to its non-linear plasma profile. The in-vivo study revealed that AUC(0-∞) of linagliptin and empagliflozin was enhanced by 2- and threefold, respectively. Therefore, the chitosan-PVP block copolymer platform buccal application for the co-delivery of linagliptin and empagliflozin could contribute to enhanced clinical effectiveness in treating diabetes.

Innovative UV Protocols Based on Straightforward Mathematical Filtration for Concurrent Estimation of Two Antidiabetic Drugs in Their Brand-New Combination: A Comparative Study.

BACKGROUND: In 2019, the U.S. Food and Drug Administration approved a brand-new combination of linagliptin and empagliflozin in a formulation called Glyxambi® tablets for managing type 2 diabetes mellitus. Nowadays, spectrophotometric techniques occupy the first place among their peers in terms of ease of application, friendliness to the environment, and low costs. OBJECTIVE: This research discusses the development of two very simple spectrophotometric protocols based on zero-order spectra for the determination of linagliptin and empagliflozin. METHODS: The developed protocols were the induced dual-wavelength and absorption correction protocols. Linagliptin could be determined directly at 305 nm, at which the empagliflozin spectrum was zero-crossing. Empagliflozin was determined using the two developed protocols. The induced dual-wavelength technique was developed by calculating the equality factor of linagliptin to cancel its interference. The absorption correction technique was developed by measuring the correction absorption factor. RESULTS: The concentration ranges of linagliptin and empagliflozin were 1-10 µg/mL and 3-30 µg/mL, respectively. Excellent recovery results were found in bulk, dosage form, and synthetic mixtures. Low LOD and LOQ values were obtained, indicating the high sensitivity of the protocols. The statistical Student's t-test was performed to compare the results of the applied and reported protocols, indicating no difference between them. CONCLUSION: The proposed protocols have the advantages of being straightforward, affordable, and requiring no sophisticated manipulations, just simple mathematical calculations. The proposed protocols are acceptable for routine usage in QC laboratories and in future research applications. HIGHLIGHTS: Two novel univariate methods were developed for quantitative analysis of linagliptin and empagliflozin in their pharmaceutical and laboratory mixtures, and produced satisfactory results.

Hydrogel-mediated tumor T cell infiltration and immune evasion to reinforce cancer immunotherapy.

Cancer immunotherapy has received increasing attention in tumor therapy. However, insufficient infiltration of T cells and over-expressed PD-L1 checkpoint in tumor cells severely impede cancer immunotherapy. Here, an injectable hydrogel was designed to reinforce T cell infiltration and inactivate PD-L1 for powerful cancer immunotherapy. The hydrogel was created by sodium alginate (SA) as the gelator, where linagliptin particles and BMS-202 particles were present in hydrogel micropores. After gelation in the tumor site, the linagliptin powerfully suppressed chemokine CXCL10 degradation, enabling the introduced CXCL10 to realize sustainable chemotaxis towards strong T cell infiltration. Meanwhile, the BMS-202 inactivated PD-L1 of tumor cells, thereby eliminating the PD-L1-governed immune evasion. Therefore, the hydrogel in combination with CXCL10 demonstrated powerful cancer immunotherapy against primary and distant tumors, along with efficient inhibition of lung metastasis. Our study not only offers a potent platform against tumors, but also provides a conceptually new approach to reinforce cancer immunotherapy.