Bioequivalence assessment of the two brands of glimepiride tablets

Evaluation of Bioequivalency and Pharmacokinetic Parameters for Two Formulations of Glimepiride 1-mg in Chinese Subjects

Purpose

Glimepiride, an FDA-approved oral hypoglycemic drug, is a long-acting sulfonylurea (SU), used for treating type 2 diabetes. The study aimed to evaluate the bioequivalence and safety profiles of two different formulations of glimepiride 1 mg from two different manufactures in healthy Chinese subjects in the fasting and fed state in order to acquire adequate pharmacokinetic evidence for registration approval of the test formulation.

Patients and Methods

This study is an open-label, two-period, two-sequence, randomized, two-way crossover pharmacokinetic study in healthy Chinese subjects in the fasting and fed state. Seventy-two subjects were randomly assigned to the fasting group and the fed group (n=36 each). We collected blood samples, 24-h post drug administration. The plasma concentration of glimepiride was assessed using HPLC coupled with mass spectrometry. The following parameters were evaluated: AUC_0-inf, AUC_0-last, C_max, t_1⁄2, T_max, and λ_z. Safety was determined based on the occurrence of adverse events (AEs) and laboratory examinations (biochemistry, hematology, and urinalysis) throughout the entire study period.

Results

The geometric mean ratios (GMR) amongst the two glimepiride formulations for the primary pharmacokinetic parameters, ie, AUC_0-inf, AUC_0-last, and C_max as well as the corresponding 90% CIs, were all within the range of 80.00-125.00% in the fasting and fed state. The safety profile for both treatments was comparable.

Conclusion

PK analysis revealed that the test and reference formulations of glimepiride were bioequivalent and well tolerated in healthy Chinese subjects. Chinese Clinical Trials Registry identifier: CTR20171121.

Clinical Trial Registration Number

CTR20171121.

Evaluation of herb-drug interaction of a polyherbal Ayurvedic formulation through high throughput cytochrome P450 enzyme inhibition assay

ETHNOPHARMACOLOGICAL RELEVANCE

Arishtas are Ayurvedic formulation made with decoction of herbs. Arjunarishta formulation is being used in Ayurveda for cardio-protective activity. Ashwagandharishta formulation possesses antioxidant, anti-atherosclerotic and anti-stress properties. Ridayarishta, a novel empirical formulation was prepared using combination of selected ingredients from these two formulations to support healthy heart functions and to reduce stress.

AIM OF THE STUDY

Aim of the Study was to investigate herb-drug interaction (HDI) of Ridayarishta formulation through human hepatic cytochrome P450 (CYP450) enzyme inhibition assay.

MATERIALS AND METHODS

Ridayarishta formulation was phyto-chemically standardized against arjunolic acid, arjunetin, berberine, piperine, resveratrol and withaferin-A using high performance thin layer chromatography (HPTLC) analysis. The formulation was standardized with respect to ethanol by gas chromatographic (GC) analysis. HDI was evaluated with Ridayarishta formulation and amlodipine besilate, atenolol, atorvastatin, metformin, glipizide glimepiride cocktail using high throughput CYP450 enzyme inhibition assay; against CYP1A2, 2C19, 2D6 and 3A4 isozymes.

RESULTS

Contents of arjunolic acid, arjunetin, berberine, piperine, resveratrol and withaferin-A in Ridayarishta formulation were found to be 1.76±0.12, 1.51±0.09, 1.85±0.05, 3.2±0.12, 1.21±0.08, and 2.16±0.09ppm, respectively. Quantity of ethanol in Ridayarishta was found to be 7.95±0.023% (V/V). Ridayarishta showed significantly higher (P<0.001) IC₅₀ value against CYP1A2 (IC₅₀-13.80±1.96µg/mL), 2C19 (IC₅₀-14.343±2.28µg/mL), 2D6 (IC₅₀-0.897±0.28µg/mL) and 3A4 (IC₅₀-32.057±2.51µg/mL) compared to positive controls such as furafylline, tranylcypromine, quinidine and ketoconazole respectively. Cocktail of herbal formulation and cardio protective, antihypertensive, anti-diabetic drugs showed significantly (P<0.001and P<0.01) less or negligible HDI.

CONCLUSION

Ridayarishta formulation alone and cocktail with amlodipine besilate, atenolol, atorvastatin, metformin, glipizide, glimepiride had negligible or insignificant effect on CYP450 inhibition. It may be concluded that consumption of Ridayarishta along with selective cardio protective, antihypertensive and anti-diabetic conventional medicine is safe with negligible or without any significant CYP450 (CYP1A2, 2C19, 2D6 and 3A4) inhibition mediated HDI.

Effects of Glimepiride on metabolic parameters and cardiovascular risk factors in patients with newly diagnosed type 2 diabetes mellitus

BACKGROUND

To investigate the effects of Glimepiride on blood glucose in patients with newly diagnosed type 2 diabetes mellitus (T2DM) in connection with plasma lipoproteins and plasminogen activity.

METHODS

A total of 565 T2DM patients were received Glimepiride (n=333) or Glibenclamide (n=232) for 12 weeks. We observed the level of blood glucose (BG), glycated hemoglobin (HbA1C), the insulin resistance (IR) state, plasma lipoproteins, tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type I (PAI-1) before and after a 12 weeks of treatment.

RESULTS

After 12 weeks with Glimepiride treatment, significant reductions were observed in fasting blood glucose (FBG) and 2-h postprandial BG(PBG), HbA1C (from 8.60+/-3.10 to 7.10+/-1.60%) and HOMA-IR (from 4.11+/-0.85 to 2.42+/-0.91%). The level of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) were significantly decreased, whereas that of high-density lipoprotein (HDL) was increased markedly with statistical significance. In addition, there was an obvious improvement in t-PA activity (from 0.225+/-0.11 to 0.457+/-0.177IU/ml); whereas the PAI-1 activity was decreased significantly (from 0.898+/-0.168 to 0.533+/-0.215AU/ml). No significant changes were observed in plasma lipoprotein profiles and plasminogen activity in Glibenclamide receiving group.

CONCLUSIONS

Glimepiride can rapidly and stably improve glycemic control and lipoprotein metabolism, significantly alleviate insulin resistance and enhance fibrinolytic activity.