Pharmacokinetics of a fixed-dose combination of mitiglinide and metformin versus concurrent administration of individual formulations in healthy subjects: a randomized, open-label, two-treatment, two-period, two-sequence, single-dose, crossover study

Pharmacokinetic and pharmacodynamic modeling of oral mitiglinide on glucose lowering in healthy Chinese volunteers

Background

Mitiglinide is a widely used agent for diabetic treatment. We established a pharmacokinetic-pharmacodynamic (PK-PD) model to illustrate the relationship between mitiglinide plasma concentration and its glucose lowering effects in healthy volunteers.

Methods

The volunteers participated in the test after the administration of a single dose of 10 mg mitiglinide. The drug concentration in Plasma and the values of glucose levels were determined by LC-MS/MS assay and hexokinase method. A PK-PD model was established with a series of equations to describe the relationship between plasma medicine and glucose, and the equations were solved numerically and fitted to the data with the Phoenix NLME software.

Results

The results of the two-compartment model analysis were based on the maximum likelihood criterion and visual inspection of the fittings. The terminal elimination half-life (t_1/2) was 1.69 ± 0.16 h and the CL/F was 7.80 ± 1.84 L/h. The plasma glucose levels began to decline by 0.2 h, and hit its bottom decreasing values of 2.6 mg/L at 0.5 h after administration. The calculated parameter and fitting curve indicated that the model established in our experiment fitted well.

Conclusions

A PK/PD model illustrates that the relationship between mitiglinide concentration in plasma and glucose lowering effect in healthy volunteers was established. The results of our experiment suggested that the model can be used reasonably to predict the relationship between PK and PD in mitiglinide, which could be used in diabetes mellitus dosage control in clinical trials and other fields.

Safety, Efficacy, and Bioavailability of Fixed-Dose Combinations in Type 2 Diabetes Mellitus: A Systematic Updated Review

Purpose

Type 2 diabetes mellitus (T2DM) is a multifactorial disease characterized by insulin resistance. As time progresses, monotherapy often does not provide effective glycemic control, generating the need for an add-on therapy. Hence, multiple oral hypoglycemic agents formulated as a single-dose form called fixed-dose combinations (FDCs) play an essential role in glycemic control. The purpose of this systematic review is to appraise the recently published evidence on the safety, efficacy, and bioavailability of FDCs.

Methods

A comprehensive literature search of PUBMED, Scopus, ScienceDirect.com, ProQuest, SpringerLink, clintrials.gov, Embase, and EBSCO using the key words FDCs, combination therapy, T2DM management, and add-on therapy was conducted. Studies on the safety profile/tolerability, efficacy, and bioavailability of various FDCs of oral hypoglycemic agents were preferred.

Findings

The systematic review of all the publications suggests that FDCs of oral hypoglycemic agents (OHAs) significantly reduce HbA_1c and fasting plasma glucose values, thereby efficiently reducing hyperglycemia in patients in whom monotherapy fails. FDCs are the bioequivalent of the concomitant drugs administered as individual components. Improved adherence to FDCs and the absence of serious adverse drug reactions compared with dual therapy play an important role in decreasing the incidence of hyperglycemia in patients with T2DM.

Implications

From this updated review, it was found that metformin was the most widely used component of FDCs with other OHAs. Studies on the safety and efficacy of newly approved OHAs such as sodium glucose cotransporter inhibitors were limited. An increasing number of randomized trials on the safety and efficacy of newly emerging FDCs suggests that they would be better treatment options for T2DM patients.

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Comprehensive analysis of current fixed-dose combinations used in the treatment of type 2 diabetes mellitus

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Most widely used component of fixed-dose combinations is metformin with other oral hypoglycemic agents (eg, like glimepiride, pioglitazone, rosiglitazone, acarbose, and sitagliptin.

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Fixed-dose combinations help to reduce hyperglycemia efficiently; the long-term complication of diabetes could be minimized in these patients, thereby improving the quality of life of patients.

Population pharmacokinetic modeling and noncompartmental analysis demonstrated bioequivalence between metformin component of metformin/vildagliptin fixed-dose combination products and metformin immediate-release tablet sourced from various countries

Metformin is the first-line pharmacotherapy choice for treating type-2 diabetes mellitus, alone or in combination with other antidiabetic drugs. During the development of immediate-release (IR) metformin containing novel fixed-dose combination (FDC) products, several health-authorities require sponsors to demonstrate bioequivalence between FDC products and the country-sourced metformin for market approval. Eight bioequivalence studies that compared metformin/vildagliptin FDC product (test) to metformin IR tablet sourced from various countries (reference) were conducted. A population pharmacokinetic (PPK) analysis of pooled metformin concentration-time data was performed to evaluate whether country-sourced metformin is a significant covariate. The PPK analysis demonstrated that there was no clinically relevant effect of metformin source or race/ethnicity on metformin pharmacokinetics. Also, noncompartmental analysis conducted showed that 90%CI of geometric mean ratios of test to reference metformin formulations, calculated for maximum-concentration and exposure parameters, were within the 80%-125% criteria, indicating comparable metformin exposure regardless of the country-sourced metformin IR formulation. These results are consistent with the biopharmaceutics properties of metformin and provide scientific evidence that after assessing in vitro dissolution of novel FDC formulation, additional bioequivalence studies with multiple countries' reference products may not be required once bioequivalence is established with 1 country-sourced IR metformin formulation.

Pharmacokinetic study of metformin to compare voglibose/metformin fixed-dose combination with coadministered voglibose and metformin

The aim of this study was to compare the pharmacokinetic characteristics of metformin between a fixed-dose combination (FDC) of voglibose/metformin and co-administered individual voglibose and metformin tablets in healthy Korean volunteers under fasting conditions. A randomized, open-label, single-dose, two-treatment, two-way crossover study with a 7-day wash-out period was conducted. Plasma samples were collected for up to 24 hours and were analyzed for metformin using a validated liquid chromatography tandem mass-spectrometry (LC/MS). A non-compartmental method was used to calculate the pharmacokinetic parameters. Vital signs and adverse events were monitored, and physical examinations and laboratory tests were conducted to evaluate safety. In total, 28 subjects completed the study. The geometric mean ratio (GMR) and the 90% confidence interval (CIs) of C_max and AUC_0–t of metformin were 102.4 (94.5 – 111.0) and 107.1 (100.1 – 114.7), respectively. In total, 7 adverse drug reactions occurred in 4 subjects during the study; of these, 3 cases were from 3 subjects in the test treatment group, and 4 cases were from 3 subjects in the reference treatment group. All adverse drug reactions had been reported previously, and all subjects recovered fully without any sequelae. In conclusion, the pharmacokinetic profiles of metformin in two different study treatments, a voglibose/metformin FDC vs. the coadministration of the individual formulations, met the regulatory criteria for bioequivalence in healthy Korean subjects under fasting conditions. There was no significant difference in safety profiles between the two treatments.