Evaluation of pharmacokinetic and pharmacodynamic parameters following single dose of sitagliptin in healthy Indian males

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Sitagliptin Phosphate Monohydrate

Sitagliptin is an antihyperglycemic drug used in adults for the treatment of diabetes Type 2. Literature data and in-house experiments were applied in this monograph to assess whether methods based on the Biopharmaceutics Classification System (BCS) could be used to assess the bioequivalence of solid immediate-release (IR) oral dosage forms containing sitagliptin phosphate monohydrate, as an alternative to a pharmacokinetic study in human volunteers. The solubility and permeability characteristics of sitagliptin were reviewed according to the BCS, along with dissolution, therapeutic index, therapeutic applications, pharmacokinetics, pharmacodynamic characteristics, reports of bioequivalence (BE) / bioavailability problems, data on interactions between the drug and excipients and other data germane to the subject. All data reviewed in this monograph unambiguously support classification of sitagliptin as a BCS Class 1 drug. In light of its broad therapeutic index and lack of severe adverse effects, the clinical risks associated with moderately supraoptimal doses were deemed inconsequential, as were the risks associated with moderately suboptimal doses. Taking all evidence into consideration, it was concluded that the BCS-based biowaiver can be implemented for solid IR oral drug products containing sitagliptin phosphate monohydrate, provided (a) the test product is formulated solely with excipients commonly present in solid IR oral drug products approved in ICH or associated countries and used in amounts commonly applied in this type of product, (b) data in support of the BCS-based biowaiver are obtained using the methods recommended by the WHO, FDA, EMA or ICH and (c) the test product and the comparator product (which is the innovator product in this case) meet all in vitro dissolution specifications provided in the WHO, FDA, EMA or ICH guidance.

Characterization and quantitative determination of henagliflozin metabolites in humans

Henagliflozin is a highly specific inhibitor of sodium-glucose co-transporter-2 (SGLT2) proposed as a more efficient medication for type 2 diabetes mellitus (T2DM). In this work, henagliflozin metabolic profile was investigated in human plasma and urine samples using a newly developed high-performance liquid chromatography coupled with time-of-flight mass spectrometry (HPLC/Q-TOF MS) method. A total of 8 metabolites were observed, while the structures of four major metabolites, including M1 (O-deethylation metabolite), M5-1 (2-O-β-glucuronide conjugate), M5-2 (6-O-β-glucuronide conjugate), and M5-3 (3-O-β-glucuronide conjugate) were confirmed in our study after comparison with the reference standards. The principal henagliflozin metabolic pathways were identified as glucuronidation and O-deethylation in humans. The principal form of henagliflozin in human plasma was parent drug, followed by M5-1; while it was M5-3 and M5-1 in urine. Subsequently, an accurate and simple LC-MS/MS method was developed for simultaneously determine M5-1, M5-2, and M5-3 in human plasma. After optimization of this method, three M5 isomers were successfully separated and quantified using chromatography. Acetonitrile-induced protein precipitation method was adapted for extracting the analytes from human plasma. Separation was conducted using Gemini C₁₈ column under gradient elution with 5 mM aqueous ammonium acetate (A) and acetonitrile (B) mobile phases. Negative electrospray ionization was conducted using a selective reaction monitoring with the same transition of m/z 629→321 for detection of three M5 isomers. The method showed good linearities for M5-1, M5-2, and M5-3 within the range of 1.00-150 ng/mL, 0.500-75.0 ng/mL, and 1.00-150 ng/mL, respectively. Conclusively, the method has been applied successfully to assess phase I henagliflozin pharmacokinetics and pharmacodynamics and providing effective safety evaluations.

Computational Approaches in Preclinical Studies on Drug Discovery and Development

Because undesirable pharmacokinetics and toxicity are significant reasons for the failure of drug development in the costly late stage, it has been widely recognized that drug ADMET properties should be considered as early as possible to reduce failure rates in the clinical phase of drug discovery. Concurrently, drug recalls have become increasingly common in recent years, prompting pharmaceutical companies to increase attention toward the safety evaluation of preclinical drugs. In vitro and in vivo drug evaluation techniques are currently more mature in preclinical applications, but these technologies are costly. In recent years, with the rapid development of computer science, in silico technology has been widely used to evaluate the relevant properties of drugs in the preclinical stage and has produced many software programs and in silico models, further promoting the study of ADMET in vitro. In this review, we first introduce the two ADMET prediction categories (molecular modeling and data modeling). Then, we perform a systematic classification and description of the databases and software commonly used for ADMET prediction. We focus on some widely studied ADMT properties as well as PBPK simulation, and we list some applications that are related to the prediction categories and web tools. Finally, we discuss challenges and limitations in the preclinical area and propose some suggestions and prospects for the future.

Decreased shedding dipeptidyl peptidase 4 from membrane in Hashimoto's thyroiditis

AIMS

This study aimed to determine the concentration and enzymatic activity of dipeptidyl peptidase 4 (DPP4) in serum and peripheral blood mononuclear cells (PBMCs) from patients with Hashimoto's thyroiditis (HT) and to explore the potential mechanism of the abnormal DPP4 in HT development.

METHODS

A total of 33 newly diagnosed HT patients and 31 age- and sex-matched healthy controls were enrolled. Clinical characteristics and thyroid function data were collected for all participants. Serum DPP4 and kallikrein-related peptidase 5 (KLK5) concentrations were measured by sandwich enzyme-linked immunosorbent assay. DPP4 enzymatic activities in serum and PBMCs were determined by enzymatic assay. DPP4, KLK5 and interferon (IFN)-γ mRNA expression levels in PBMCs were evaluated by quantitative real-time polymerase chain reaction.

RESULTS

Serum DPP4 level and activity were significantly lower in the HT group compared with the control group. However, DPP4 mRNA expression was significantly increased and both serum KLK5 concentration and KLK5 mRNA expression in PBMCs were significantly decreased in HT patients. Correlation analyses revealed that DPP4 concentration was positively correlated with DPP4 enzymatic activity in serum. No significant difference in DPP4 activity was found in PBMCs. DPP4 enzymatic activity in PBMCs was negatively correlated with DPP4 enzymatic activity in serum. IFN-γ mRNA expression in PBMCs was significantly increased in HT patients.

CONCLUSIONS

DPP4 is involved in the development and pathological process of HT. Decreased cleavage of membrane-anchored DPP4 by KLK5 may be responsible for the decreased serum DPP4 levels in HT patients.

Comparative pharmacokinetic evaluation of extended release itopride HCl pellets with once daily tablet formulation in healthy human subjects: a two treatment, four period crossover study in fasted and fed condition

OBJECTIVE

In this study, pharmacokinetics (PKs) and bioavailability of newly developed extended release (ER) Itopride HCl 150 mg encapsulated ER pellets (test) and 150 mg Ganaton ER once-daily (OD) tablets (reference) were compared and evaluated under fasted and fed conditions.

METHODS

Twelve healthy human subjects were enrolled in a single dose, randomized; two treatments, two sequences, four period crossover study. A modified and validated liquid chromatographic method was used for the estimation of Itopride HCl in plasma samples. The data were analyzed through non-compartmental model using PK software Phoenix Winnonlin version 7. The outcome was measured on logarithmically transformed data, where p > 0.05 was considered as non-significant with 90% CI limit of 0.8-1.25.

RESULTS

The C_max, AUC_0-t, and AUC_0-∞ values of Itopride HCl 150 mg ER pellets versus that of OD 150 mg tablets, in fed and fasted states, were within the limits specified by FDA to establish bioequivalence. The relative bioavailability of Itopride HCl 150 mg ER pellets were 1.019 (fed) and 1.081(fasted). The 90% CIs of AUC values for Itopride HCl 150 mg ER pellets and OD 150 mg tablets in fed versus fast were significantly greater and were not within 80-125% limit.

CONCLUSION

The test and reference formulations had similar pharmacokinetic parameters in each condition studied. However, an increase in the amount of drug was observed in the fed state.