Different chromatographic methods for determination of alogliptin benzoate, metformin hydrochloride, and metformin impurity in bulk and pharmaceutical dosage form.

Two simple, sensitive, and reproducible methods were developed for the determination of alogliptin and metformin hydrochloride in presence of metformin impurity "melamin" in pure form and in pharmaceutical formulation. Method (A) was a thin layer chromatographic method in which separation was achieved using ethyl acetate-methanol-formic acid (6:3.8:0.2, by volume) as a developing system followed by densitometric scanning at 230 nm. Method (B) was a high-performance liquid chromatography method; separation was achieved on C18 column, the mobile phase consisted of a mixture of sodium lauryl sulfate buffer 0.1% w/v, pH 3: methanol in the ratio 70:30, v/v and measurement was done at 220 nm. System suitability testing parameters were calculated to ascertain the quality performance of the developed chromatographic methods. The proposed methods have been validated regarding accuracy, precision, and selectivity, moreover they have been successfully applied to Westirizide tablets containing both alogliptin and metformin hydrochloride, results indicate that there was no interference from additives. No significance difference was found when these methods were compared to the reported one.

Novel spectrofluorimetric quantification of alogliptin benzoate in biofluids exploiting its interaction with 4-chloro-7-nitrobenzofurazan.

The direct determination of alogliptin benzoate (ALO) using fluorescence has not yet been accomplished because ALO cannot fluoresce naturally. Accordingly, it should be derivatized first with a fluorogenic reagent to enhance the sensitivity required for its bioanalysis. This method is the first spectrofluorimetric assay for ALO quantification exploiting the nucleophilic nature of its amino group to react with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in borate buffer at pH 8.5 to produce a strong fluorescent compound that is excited at and emits at wavelengths 470 and 527 nm, respectively. Experimental variables concerning the conditions of reaction and fluorogenic intensity were carefully investigated and optimized. Linearity was from 1-250 ng ml-1 with a lower detection limit of 0.29 ng ml-1 and a lower quantification limit of 0.88 ng ml-1 . Validation of the current study was accomplished with mean per cent recovery of 100.62 ± 1.59 in tablets and 99.86 ± 0.82 in human plasma. Furthermore, the current method has been utilized in the bioanalysis of ALO in real rat plasma after oral administration with a simple specimen preparation. The developed method has proven to be a promising alternative method for ALO analysis in bioequivalence studies.

Characterization of process-related impurities including forced degradation products of alogliptin benzoate and the development of the corresponding reversed-phase high-performance liquid chromatography method.

The characterization of process-related impurities and forced degradants of alogliptin benzoate (Alb) in bulk drugs and a stability-indicating HPLC method for the separation and quantification of all the impurities were investigated. Alb was found to be unstable under acid and alkali stress conditions and two major degradation products (Imp-F and Imp-G) were observed. The optimum separation was achieved on Kromasil C18 (250 × 4.6 mm, 5 µm) using 0.1% perchloric acid (pH adjusted to 3.0 with triethylamine) and acetonitrile as a mobile phase in gradient mode. The proposed method was found to be stability indicating, precise, linear (0.10-75.0 µg/mL), accurate, sensitive, and robust for the quantitation of Alb and its process-related substances and degradation products. The structures of 11 impurities were characterized and confirmed by NMR spectroscopy, MS, and IR spectroscopy, and the most probable formation mechanisms of all impurities were proposed according to the synthesis route.

Unveiling the interaction mechanism of alogliptin benzoate with human serum albumin: Insights from spectroscopy, microcalorimetry, and molecular docking and molecular dynamics analyses.

The interaction between a DPP-4 inhibitor, alogliptin benzoate (AB), and human serum albumin (HSA) was systematically investigated via spectroscopy, microcalorimetry and molecular simulations. Steady-state fluorescence and time-resolved fluorescence spectrometry illustrated that the fluorescence quenching type of AB to HSA was static and caused by the formation of ground state AB-HSA complex. Isothermal titration calorimetry (ITC) combined with fluorescence spectra revealed that the affinity of AB to the subdomain IIA of HSA was moderate with a binding constant in the order of 104. Molecular docking analysis and thermodynamic parameters demonstrated that this combination was maintained by hydrogen bonding along with van der Waals force and hydrophobic force. Circular dichroism and three-dimensional (3D) fluorescence showed that AB increased the hydrophobicity of Trp residue and the α-helix content of HSA by 1.99%. Microdifferential scanning calorimetry revealed that the addition of AB enhanced the thermal stability of HSA. The action forces, binding stability, binding sites, and protein structure of the AB-HSA system were evaluated via molecular dynamics analysis in the simulated environment. On the basis of molecular docking, MD simulation constructed a more reliable 3D model of the AB-HSA complex in terms of spatial structure.

Study on the mechanism of improving islet β-cell function in patients with type 2 diabetes mellitus by Alogliptin benzoate / 中国糖尿病杂志

Objective To investigate the effect of Alogliptin benzoate on the serum autophagy markers in type 2 diabetes mellitus(T2DM)patients.Methods Eighty newly diagnosed T2DM patients who visited the Department of Endocrinology in Baoding No.1 Central Hospital from December 2021 to October 2022 were randomly divided into a group treated with Metformin(Met group,n=40)and a group treated with Met and Alog(Met+Alog group,n=40).The differences in BMI,WHR,FPG,HbA1c,Atg7 and Beclin-1 between two groups before and after 12 weeks of treatment were compared.Results After treatment,the levels of Atg7 and Beclin-1 increased in both groups(P<0.05),while FPG,HbA1c and HOMA-IR decreased(P<0.05).After treatment,Atg7,Beclin-1 and HDL-C in Met+Alog group were higher than those in Met group(P<0.05).Pearson correlation analysis showed that Atg7 was negatively correlated with BMI,FPG and HbA1c(P<0.05);Beclin-1 was positively correlated with HDL-C(P<0.05),and negatively correlated with BMI,FPG,HbA1c,and TG(P<0.05).Meta linear regression analysis showed that BMI was the influencing factor of Atg7,while BMI and HDL-C were the influencing factors of Beclin-1.Conclusion Alogliptin benzoate may improve islet β cell function by up-regulating the expression of autophagy related factors Atg7 and Beclin-1 in patients with T2DM.

An up-to-date evaluation of alogliptin benzoate for the treatment of type 2 diabetes.

Introduction: A growth in the market for anti-diabetic drugs, along with an ever-increasing population suffering from type 2 diabetes mellitus (T2DM), requires a critical re-evaluation of anti-diabetic drugs used for a long time, in order to provide up-to-date practical prescribing information for clinicians. Alogliptin benzoate was firstly approved in 2010 in Japan for T2DM, both as a monotherapy or in combination with other anti-diabetic drugs. Areas covered: This article provides a comprehensive review of the latest data on alogliptin benzoate, including hypoglycemic activity and safety. Expert opinion: The cumulative evidence for alogliptin benzoate is robust with regards to glycemic efficacy and safety. Low hypoglycemia risks and weight changes support its consideration as a first-line medication for T2DM, either as a monotherapy or in combination therapy with other anti-diabetic drugs such as metformin. Ongoing trials will look to better analyze and address its safety and efficacy in pediatric patients and expand our clinical knowledge of this medication.

Isolation and characterization of related substances in alogliptin benzoate by LC-QTOF mass spectrometric techniques.

A highly specific and efficient LC-QTOF mass spectrometric method was developed for the separation and characterization of process related substances and the major degradation products in alogliptin benzoate and its tablets. The separation was performed on Phenomenex Gemini-NX C18 column (250mm×4.6mm, 5µm) using 0.2% formic acid-0.2% ammonium acetate in water as mobile phase A, acetonitrile and methanol (60:40, v/v) as mobile phase B in linear gradient elution mode. Forced degradation studies were also conducted under ICH prescribed stress conditions. Alogliptin benzoate and its tablets were tending to degrade under acid, alkaline, oxidative and thermal stresses, while relatively stable to photolytic stress. A total of seven related substances were detected and characterized through liquid chromatography-high resolution QTOF mass spectrometry techniques, including process related substances and degradation products, and two of them were further synthesized and characterized by NMR spectroscopy. Based on the related substances elucidation and the plausible formation mechanisms, efficient approaches were proposed to reduce or eliminate related substances, and in consequence the quality of alogliptin benzoate and its tablets have been promoted obviously. Therefore, the impurity profiles obtained are critical to the quality control and manufacturing processes optimization and monitoring of alogliptin benzoate and its tablets.

Isolation and identification of unknown impurities of alogliptin benzoate / 中国药科大学学报

@#By silica gel column chromatography, solvent extraction and preparative high performance liquid chromatography (HPLC), four new related substance were isolated and purified from the mass production and preparation process of alogliptin benzoate. Then it was analyzed and confirmed by various spectrum identification methods such as nuclear magnetic resonance (NMR) spectroscopy, high-resolution mass spectrometry (HR-MS) and Fourier-transform infrared spectroscopy (FTIR) according to its physical and chemical properties. The chemical structures of the four related substances produced in each step of the synthesis process of alogliptin benzoate were determined, and they were named as impurities L, M, T, and V. These four related substances were new impurities which were found for the first time. The isolation and identification of these impurities are of great importance to the quality control of alogliptin benzoate, and the optimization of manufacturing process.