Response of 1,5-anhydroglucitol level to intensive glucose- and blood-pressure lowering interventions, and its associations with clinical outcomes in the ADVANCE trial.

AIMS: To evaluate 1,5-anhydroglucitol (1,5-AG) according to clinical outcomes and assess the effects of glucose- and blood pressure-lowering interventions on change in 1,5-AG levels in people with type 2 diabetes. METHODS: We measured 1,5-AG in 6826 stored samples at baseline and in a random subsample of 684 participants at the 1-year follow-up visit in the ADVANCE trial. We examined baseline 1,5-AG [< 39.7, 39.7-66.2, ≥ 66.2 µmol/L (<6, 6-10, ≥10 µg/mL)] and microvascular and macrovascular events and mortality using Cox regression models during 5 years of follow-up. Using an intention-to-treat approach, we examined 1-year change in 1,5-AG (mean and percent) in response to the glucose- and blood pressure-lowering interventions in the subsample. RESULTS: Low 1,5-AG level [<39.7 µmol/L vs ≥ 66.2 µmol/L (<6 µg/mL vs ≥10 µg/mL)] was associated with microvascular events (hazard ratio 1.28, 95% confidence interval 1.03-1.60) after adjustment for risk factors and baseline glycated haemoglobin (HbA1c); however, the associations for macrovascular events and mortality were not independent of HbA1c. The glucose-lowering intervention was associated with a significant 1-year increase in 1,5-AG (vs standard control) of 6.69 µmol/L (SE 2.52) [1.01 µg/mL (SE 0.38)], corresponding to an 8.26% (SE 0.10%) increase from baseline. We also observed an increase in 1,5-AG of similar magnitude in response to the blood pressure intervention independent of the glucose-lowering effect. CONCLUSIONS: Our results suggest that 1,5-AG is a marker of risk in adults with type 2 diabetes, but only for microvascular events independently of HbA1c. We found that 1,5-AG was improved (increased) in response to an intensive glucose-lowering intervention, although the independent effect of the blood pressure-lowering intervention on 1,5-AG suggests potential non-glycaemic influences.

Optimization of gliclazide loaded alginate-gelatin beads employing central composite design.

Objective: The aim of this study was to optimize the formulation of alginate-gelatin (AL-GL) beads containing gliclazide (GLZ) employing design of experiments (DOE).Significance: DOE enabled identification of the interaction between the studied factors, deep understanding of GLZ release pattern and acceleration of the optimization process.Methods: A three-factor, three-level face centered design was employed. The effects of GLZ content (GLZ%, X1), polymer ratio (AL:GL ratio, X2), crosslinker concentration (glutaraldehyde, GA%, X3), and their interaction on incorporation efficiency (IE) and release rate were studied. The optimized formulation was prepared using numerical optimization and evaluated by DSC, FT-IR, SEM and release rate studies.Results: Increasing GA% (X3) decreased IE (Y1) with the highest magnitude of effect among the studied factors. On the other hand, increasing alginate content in AL:GL ratio (X2) increased IE (Y1). The amount of GLZ released Q0.5h, Q2h(pH 1.2) and Q4h(pH 7.4) decreased by increasing GLZ% (X1) and AL:GL ratio (X2). Both drug content and AL:GL ratio appeared to affect water penetration into the gel matrix and drug release. Generally, there was a direct relationship between GA% (X3) and GLZ release in pH 1.2 (Q0.5h and Q2h). However, in pH 7.4 (Q4h), increasing GA% decreased GLZ release. In addition, increasing GA% caused deviation from zero-order release model. The actual responses of the optimized formulation were in close agreement with the predicted ones.Conclusion: The selected factors and their levels studied in the optimization design were useful for tailoring the anticipated formulation characteristics and GLZ release pattern.

Quality by Design Approach for Developing Lipid-Based Nanoformulations of Gliclazide to Improve Oral Bioavailability and Anti-Diabetic Activity.

The aim of the current investigation was to generate a self-nanoemulsifying drug delivery system (SNEDDS) of gliclazide (GCZ) to address the poor solubility and bioavailability. Ternary phase diagram was created with Capmul MCM C8 NF (oil), Cremophor RH 40 (surfactant), and Transcutol HP (co-surfactant) to distinguish the self-emulsifying region. A D-optimal design was employed with three variables, such as oil, surfactant, and co-surfactant, for further optimization of liquid (L)-SNEDDS. GCZ-loaded L-SNEDDs were analyzed for globule size, polydispersity index (PDI), and solubility. In vitro dissolution of optimized L-SNEDDS exhibited (F5) faster drug release (97.84%) within 30 min as compared to plain drug (15.99%). The optimized L-SNEDDS was converted to solid (S)-SNEDDS as a self-nanoemulsifying powder (SNEP) and pellets by extrusion-spheronization. Optimized S-SNEDDS were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). In vitro dissolution of SNEP (S3) and pellet were 90.54 and 73.76%, respectively, at 30 min. In vivo studies showed a twofold rise in bioavailability through SNEDDS with a significant decline in blood glucose levels compared to plain drug suspension suggesting a lipid-based system as an alternative approach for treating diabetes.

Serum Metabolomics Study of Gliclazide-Modified-Release-Treated Type 2 Diabetes Mellitus Patients Using a Gas Chromatography-Mass Spectrometry Method.

Sulfonylureas are one of the commonly used drugs in type 2 diabetes mellitus (T2DM) but with considerable incidence of monotherapy failure. However, the mechanism of patients' drug response is unclear, and suitability evaluation biomarkers are in urgent need for precision medicine. In this study, a pseudotargeted gas chromatography-mass spectrometry method was employed to investigate the serum metabolic profiling of 66 significant responders and 24 nonsignificant responders at baseline and 16 weeks after gliclazide modified-release (MR) monotherapy. Clinical improvements in blood glucose level and insulin sensitivity were closely associated with the alterations of TCA cycle, ketone body metabolism, lipid oxidation, branched-chain amino acid catabolism, and gut flora metabolism. The different baseline metabolic profiling observed in the two groups implied that patients with lower dyslipidemia level may be more suitable for sulfonylurea therapy. The biomarker panel consisting of HbA1c, 5,8,11,14,17-eicosapentaenoic acid, methyl 8,11,14-eicosatrienoate, and methyl hexadecanoate shows a very good prediction ability for the suitability of gliclazide treatment, and it may be meaningful in personalized medicine of T2DM patients by sulfonylurea therapy.

Haemoglobin glycation index and risk for diabetes-related complications in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial.

AIMS/HYPOTHESIS: Previous studies have suggested that the haemoglobin glycation index (HGI) can be used as a predictor of diabetes-related complications in individuals with type 1 and type 2 diabetes. We investigated whether HGI was a predictor of adverse outcomes of intensive glucose lowering and of diabetes-related complications in general, using data from the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial. METHODS: We studied participants in the ADVANCE trial with data available for baseline HbA1c and fasting plasma glucose (FPG) (n = 11,083). HGI is the difference between observed HbA1c and HbA1c predicted from a simple linear regression of HbA1c on FPG. Using Cox regression, we investigated the association between HGI, both categorised and continuous, and adverse outcomes, considering treatment allocation (intensive or standard glucose control) and compared prediction of HGI and HbA1c. RESULTS: Intensive glucose control lowered mortality risk in individuals with high HGI only (HR 0.74 [95% CI 0.61, 0.91]; p = 0.003), while there was no difference in the effect of intensive treatment on mortality in those with high HbA1c. Irrespective of treatment allocation, every SD increase in HGI was associated with a significant risk increase of 14-17% for macrovascular and microvascular disease and mortality. However, when adjusted for identical covariates, HbA1c was a stronger predictor of these outcomes than HGI. CONCLUSIONS/INTERPRETATION: HGI predicts risk for complications in ADVANCE participants, irrespective of treatment allocation, but no better than HbA1c. Individuals with high HGI have a lower risk for mortality when on intensive treatment. Given the discordant results and uncertain relevance beyond HbA1c, clinical use of HGI in type 2 diabetes cannot currently be recommended.

Follow-up of blood-pressure lowering and glucose control in type 2 diabetes.

BACKGROUND: In the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) factorial trial, the combination of perindopril and indapamide reduced mortality among patients with type 2 diabetes, but intensive glucose control, targeting a glycated hemoglobin level of less than 6.5%, did not. We now report results of the 6-year post-trial follow-up. METHODS: We invited surviving participants, who had previously been assigned to perindopril-indapamide or placebo and to intensive or standard glucose control (with the glucose-control comparison extending for an additional 6 months), to participate in a post-trial follow-up evaluation. The primary end points were death from any cause and major macrovascular events. RESULTS: The baseline characteristics were similar among the 11,140 patients who originally underwent randomization and the 8494 patients who participated in the post-trial follow-up for a median of 5.9 years (blood-pressure-lowering comparison) or 5.4 years (glucose-control comparison). Between-group differences in blood pressure and glycated hemoglobin levels during the trial were no longer evident by the first post-trial visit. The reductions in the risk of death from any cause and of death from cardiovascular causes that had been observed in the group receiving active blood-pressure-lowering treatment during the trial were attenuated but significant at the end of the post-trial follow-up; the hazard ratios were 0.91 (95% confidence interval [CI], 0.84 to 0.99; P=0.03) and 0.88 (95% CI, 0.77 to 0.99; P=0.04), respectively. No differences were observed during follow-up in the risk of death from any cause or major macrovascular events between the intensive-glucose-control group and the standard-glucose-control group; the hazard ratios were 1.00 (95% CI, 0.92 to 1.08) and 1.00 (95% CI, 0.92 to 1.08), respectively. CONCLUSIONS: The benefits with respect to mortality that had been observed among patients originally assigned to blood-pressure-lowering therapy were attenuated but still evident at the end of follow-up. There was no evidence that intensive glucose control during the trial led to long-term benefits with respect to mortality or macrovascular events. (Funded by the National Health and Medical Research Council of Australia and others; ADVANCE-ON ClinicalTrials.gov number, NCT00949286.).

Epidemiologic Surveillance of Glycemic Response to a Scored, Breakable, Extended Release, Fixed Dose Combination of Gliclazide and Metformin in Persons with Type 2 Diabetes.

BACKGROUND: The combination of metformin and a sulphonylurea has been recommended for treatment of type 2 diabetes. A, scored, breakable, extended release, once daily fixed dose combination (FDC) of gliclazide and metformin is available in India. OBJECTIVE: To assess the initial blood glucose lowering efficacy, glycemic control and patient acceptability of the fixed dose combination of original gliclazide 60mg and metformin 500mg in an extended release, scored and breakable formulation (in a range of 1, 1½, and 2 tablets) among Indian patients in day to day practice. METHODS: In a multi-center epidemiologic surveillance protocol of 60 days, patients with type 2 diabetes were prospectively prescribed 1 to 2 tablet of gliclazide 60mg + metformin 500mg during the course of study. The possibility of breaking the tablet in two equal halves enabled administration of 1½ tablets wherever required. Primary data on fasting plasma glucose response and adverse events was extracted for analysis from the case records of patients kept with the investigators. The primary outcome was the proportion of patients achieving glycemic control, defined as fasting plasma glucose of 90-130 mg/dl at the end of the study. RESULTS: Of the 759 patients treated with an extended release FDC of gliclazide 60mg + metformin 500mg, the number (%, 95% CI) which achieved glycemic control was 474/759 (62.5%, 59.0% to 65.8%). The proportion controlled with 1 tablet was, 252/759 (33.2%, 29.9% to 36.6%); with 1½ tablets, 149/298, (50.0%, 44.3% to 55.6%); and with 2 tablets, 73/94, (77.5%, 68.2% to 85.0%). Mean (95% CI) FPG mg/dl decreased from baseline by 48.7 (45.0 to 51.4) with 1 tablet; by 71.3 (66.0 to 76.6) with 1½ tablets; and by 86.3 (75.7 to 96.9) with 2 tablets. Frequency of hypo-glycaemia was 0.7%. CONCLUSIONS: Extended release FDC of gliclazide 60mg + metformin 500mg, a scored, breakable, once daily, formulation was effective in controlling blood glucose in a large proportion of type 2 diabetes with a low risk of hypoglycaemia.

[Glycemic variability and oxidative stress in patients with type 2 diabetes mellitus during combined glucose-lowering therapy]. / Variabel'nost' urovnia gliukozy v krovi i okislitel'nyi stress u bol'nykh sakharnym diabetom 2-go tipa na fone kombinirovannoi sakharosnizhaiushchei terapii.

AIM: To evaluate the impact of intensified glucose-lowering therapy on carbohydrate metabolic indicator, such as glycated hemoglobin, fasting blood glucose level (BGL) (FBGL), postprandial BGL (PBGL), and glycemic variability (GV) in patients with type 2 diabetes mellitus (T2DM) during metformin monotherapy before and 3 months after therapy intensification. SUBJECTS AND METHODS: The investigation enrolled 51 patients with T2DM treated with metformin 1000 mg twice daily, who failed to achieve satisfactory glycemic control. During randomization, the treatment was intensified by addition of sitagliptin 100 mg/day in Group 1 (n=25) or gliclazide MB 60 mg/day in Group 2 (n=26). Before and 3 months after the treatment, carbohydrate metabolic indicators were investigated, 24-hour BGL monitoring (continuous glucose monitoring system (GMS)) was performed, and the body's antioxidant status was examined by determining the total antioxidant capacity of blood plasma (overall sound pressure levels (OASPL)). RESULTS: During 3-month treatment, Group 1 had a significantly reduced FBGL compared to that before the therapy; in Group 2 this index did not change significantly. Both study groups showed a significant decrease in PBGL and glycated hemoglobin (HbA1c). The mean amplitude of glycemic excursion (MAGE) was significantly decreased in the sitagliptin intensification group. In both groups, the standard deviation (SD) reduced significantly by 26% in Group 1 and by 38% in Group 2. Both groups also displayed a significant increase in blood OASPL (p<0.05). CONCLUSION: The addition of sitagliptin significantly affected the change in the indicators of both the standard carbohydrate metabolism (FBGL, PBGL, and HbA1c) and GV (MAGE, SD), whereas that of gliclazide MV altered some studied parameters. OASPL significantly increased in both groups.

Dose-response relationship between sulfonylureas and major adverse cardiovascular events in elderly patients with type 2 diabetes.

PURPOSE: The objective of this study was to determine if there is a dose-response relationship between sulfonylureas and major adverse cardiovascular events (MACE). METHODS: We conducted a retrospective cohort study among elderly patients with no history of acute coronary syndrome or stroke who initiated gliclazide or glyburide therapy between 1998 and 2010. Gliclazide and glyburide users were evaluated separately, and a high-dimensional propensity score (HDPS) was used to match patients initiating therapy with a low or high dose. A time-dependent variable was used to further characterize exposure, which can change during follow-up. Cox proportional hazard regression models were used to compare the risk of MACE between low (reference) and high doses. RESULTS: We identified 14,213 new users of gliclazide or glyburide (mean age, 74.7 (standard deviation 6.4) years; males, 52.8%; and mean follow-up duration, 2.7 (standard deviation 2.9) years). Among gliclazide users, there was a higher risk of MACE with high compared with low dose (crude rates: 32.8 and 28.2 per 1000 person-years, respectively), but this did not reach statistical significance (HDPS-matched hazard ratio) 1.15; 95% confidence interval (0.96-1.38). For glyburide users, however, MACE occurred more frequently in the high compared with low dose (crude rates: 38.9 and 31.5 per 1000 person-years, respectively; HDPS-matched hazard ratio 1.24; 95% confidence interval 1.02-1.50). CONCLUSIONS: Among new users of sulfonylureas, there appears to be a dose-response relationship between glyburide and MACE, but not for gliclazide. Copyright © 2016 John Wiley & Sons, Ltd.

An advanced microencapsulated system: a platform for optimized oral delivery of antidiabetic drug-bile acid formulations.

INTRODUCTION: In previous studies, we have shown that a gliclazide-cholic acid derivative (G-CA) mixture resulted in an enhanced ileal permeation of G (ex vivo). When administered orally to diabetic rats, it brought about a significant hypoglycaemic effect. In this study, we aim to create a novel microencapsulated-formulation of G-CA with uniform and coherent structure that can be further tested in our rat model of type 1 diabetes (T1D). We also aim to examine the effect of CA addition to G microcapsules in the morphology, structure and excipients' compatibility of the newly designed microcapsules. METHOD: Microencapsulation was carried out using our Buchi-based microencapsulating system developed in our laboratory. Using sodium alginate (SA) polymer, both formulations were prepared: G-SA (control) and G-CA-SA (test) at a constant ratio (1:3:30), respectively. Complete characterizations of microcapsules were carried out. RESULTS: The new G-CA-SA formulation is further optimized by the addition of CA exhibiting pseudoplastic-thixotropic rheological characteristics. Bead size remains similar after CA addition, the new microcapsules show no chemical interactions between the excipients and this was supported further by the spectral studies suggesting bead stability. CONCLUSION: The new microencapsulated-formulation has good and uniform structural properties and may be suitable for oral delivery of antidiabetic-bile acid formulations.

Effects of metformin plus gliclazide versus metformin plus glimepiride on cardiovascular risk factors in patients with type 2 diabetes mellitus.

High blood glucose level, lipid profile disturbances and plasma homocysteine (Hcy) are important risk factors for cardiovascular diseases in patients with type 2 diabetes. This study was conducted to evaluate and compare effects of glimepiride/metformin combination versus gliclazide/metformin combination on cardiovascular risk factors in type-2 diabetes mellitus (T2DM) patients. One hundred and eighty T2DM patients were randomly allocated for treatment with placebo (control), metformin (500 mg twice daily), glimepiride (3mg once daily), gliclazide (80 mg once daily), metformin plus glimepiride or metformin plus gliclazide for 3 months. We evaluated plasma levels of glucose (PG), glycated hemoglobin (HbA1C), Hcy, vitamin B12, folic acid and lipid profile before treatment and 3 months post treatment. Compared to metformin treated patients, glimepiride plus metformin induced significant reductions in: fasting plasma glucose, postprandial PG level, HbA1C % and Hcy level. Conversely, plasma folic acid and vitamin B12 were significantly increased. The levels of total cholesterol and triglyceride were significantly decreased; low-density lipoprotein was markedly decreased, whereas high-density lipoprotein was significantly increased and hence risk ratio was significantly decreased. Similar results but with lower values were obtained using combination of metformin plus gliclazide on glycemic control only. Combination of glimepiride with metformin was superior to gliclazide plus metformin in alleviating the cardiovascular risk factors in type 2 diabetes mellitus patients.

Risk of acute coronary events associated with glyburide compared with gliclazide use in patients with type 2 diabetes: a nested case-control study.

AIM: Sulfonylureas might increase the risk of adverse cardiovascular events; however, emerging evidence suggests there may be important differences amongst these drugs. Some, like glyburide, inhibit KATP channels in the heart and pancreas, while others, like gliclazide, are more likely to selectively inhibit KATP channels in the pancreas. We hypothesized that the risk of acute coronary syndrome (ACS) events would be higher in patients using glyburide compared with gliclazide. METHODS: This nested case-control study used administrative health data from Alberta, Canada. New users of glyburide or gliclazide aged ≥66 years between 1998 and 2010 were included. Cases were individuals with an ACS-related hospitalization or death. Up to four controls were matched based on birth year, sex, cohort-entry year and follow-up time. Multivariable conditional logistic regression was used to estimate adjusted odds ratios (OR), controlling for baseline drug use and co-morbidities. RESULTS: Our cohort included 7441 gliclazide and 13 884 glyburide users; 51.4% men, mean (s.d.) age 75.5 (6.6) years and mean (s.d.) duration of follow-up 5.5 (4.0) years. A total of 4239 patients had an ACS-related hospitalization or death and were matched to 16 723 controls. Compared with gliclazide use, glyburide use was associated with a higher risk (adjusted OR 1.14; 95% CI 1.06-1.23) of ACS-related hospitalization or death over 5.5 years (number needed to harm: 50). CONCLUSION: In this observational study, glyburide use was associated with a 14% higher risk of ACS events compared with gliclazide use. Although the difference is small and probably to have implications at the population level rather than the individual patient or clinician, any causal inferences regarding sulfonylurea use and adverse cardiovascular risk should be tested in a large-scale randomized controlled trial.

Development of novel gastroretentive drug delivery system of gliclazide: hollow beads.

AIM: The current communication deals with the development of hollow floating beads of gliclazide. The primary effect of this drug is to potentiate glucose-stimulated insulin release from pancreatic islet-ß-cells by induction of a decrease in potassium efflux from these cells. Because of the poor aqueous solubility, its absorption is limited. Thus, an attempt was made to improve its release profile. METHODS: The hollow drug-loaded alginate beads in combination with low methoxyl pectin and hydroxypropylmethylcellulose (HPMC) were prepared by a simple ionotropic gelation method. The beads were evaluated for particle size and morphology using optical microscopy and scanning electron microscopy (SEM), respectively. Mucoadhesion test was done using goat stomach mucosal membrane. Release characteristics of the gliclazide-loaded hollow beads were studied in 0.1 N HCl (pH 1.2) and phosphate buffer (pH 5.8). RESULTS: The developed beads were spherical in shape with hollow internal structure and had a particle size in the range of 0.730 ± 0.05 to 0.890 ± 0.03 mm. The incorporation efficiency of alginate -pectin beads was higher than alginate -HPMC beads. The Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction analysis showed stable character of drug in the drug-loaded hollow beads and revealed the absence of any drug -polymer interactions. The beads remained buoyant for more than 12 h. The drug release from beads followed Fickian diffusion with swelling. CONCLUSION: The preliminary results of this study suggest that the developed beads containing gliclazide could enhance drug entrapment efficiency, reduce the initial burst release and modulate the drug release.

Do geriatrics require dose titration for antidiabetic agents?

OBJECTIVE: To evaluate the antidiabetic drug dosage differences between geriatric and nongeriatric diabetics with reference to duration of disease and creatinine clearance (Crcl). MATERIALS AND METHODS: Prospective study conducted for 6 months in a tertiary care hospital. Patients with type 2 diabetes mellitus were grouped into geriatric (age ≥60 years) and nongeriatric (age <60 years). Patients' demographic data, duration of diabetes, medication, and serum creatinine were recorded. Crcl was calculated using Cockcroft-Gault formula. Doses of sulfonylureas (SU) were converted into equivalent doses, taking glibenclamide as standard. Univariate analysis was done for comparison of drug doses between groups. RESULT: A total of 320 geriatric and 157 nongeriatric diabetics completed the study. The duration of diabetes and Crcl adjusted dose reduction of glibenclamide (mean dose: Geriatrics 7.2±0.4 mg, nongeriatrics 9.6±0.7 mg; P=0.01) and gliclazide (mean dose: Geriatrics 85.5±11.5 mg, nongeriatrics 115.3±32.7 mg; P=0.42) was 25%, glimepiride (mean dose: Geriatrics 1.62±0.13 mg, nongeriatrics 2.1±0.18 mg; P=0.06) was 22%. Glipizide did not require dose reduction. Mean converted equivalent dose of sulfonylurea monotherapy was significantly lower in geriatrics than nongeriatrics (3.2±0.5 vs 6.4±1.02 mg; P=0.01) and showed 50% dose reduction. Mean dose of metformin was lower in geriatrics (901±32.2 mg vs 946.7±45.8 mg; P=0.45) and showed 5% reduction in dosage. There was no difference in the mean drug doses of thiazolidinediones and insulin between the groups. CONCLUSION: A substantial dose reduction of glibenclamide (25%), gliclazide (25%), glimepiride (22%), and metformin (5%) in geriatrics compared to nongeriatrics was observed. Smaller dosage formulations like 0.75 mg glibenclamide, 0.5 mg glimepiride, 20 mg gliclazide, and 250 mg metformin may be of value in geriatric diabetic practice.

In vitro and in vivo evaluation of gliclazide push-pull osmotic pump coated with aqueous colloidal polymer dispersions.

The objective of present work was to design and evaluate gliclazide push-pull osmotic pump (PPOP) coated with aqueous colloidal polymer dispersions-Eudragit(®) RL 30D and Eudragit(®) RS 30D. The influence of diacetin, diethyl phthalate (DEP), dibutyl sebacate (DBS) and triethyl citrate (TEC) on the free Eudragit(®) RL 30D and Eudragit(®) RS 30D films as plasticizers on drug release were studied. Among these four plasticizers, diacetin offered the smoothest surface of the cast films, and it displayed greatest water vapor transmission coefficient. Free RL and RS films with diacetin also exhibited greatest erosion compared with the other three plasticizers. On the other hand, TEC, DEP and DBS showed greater water absorption. When compared with CA-coated gliclazide PPOP, Eudragit-coated ones showed a f(2) factor of 71.7, indicating the similarity between the release profile of the two formulations. The prepared Eudragit-coated gliclazide PPOP showed typical Zero-order release characteristics, with R being 0.9953. In the in vivo evaluation, the mean relative oral bioavailability of Eudragit-coated PPOP compared to CA-coated ones was 106.9%, demonstrating good bioequivalence. Both of their in vitro-in vivo correlation (IVIVC) showed linear relationship, with R(2) being 0.9955 (Eudragit-coated PPOP) and 0.9987 (CA-coated PPOP), respectively. These results suggested that PPOP coated with Eudragit(®) RL 30D and RS 30D could overcome drawbacks of organic solution coating and promote the development of PPOP.

Effect of two hydrophobic polymers on the release of gliclazide from their matrix tablets.

Gliclazide is an oral hypoglycemic agent, indicated in non insulin dependent diabetes mellitus and in patients with diabetic retinopathy. It has good tolerability and is a short acting sulfonyl urea that requires large dose to maintain the blood glucose level. So development of a sustained release formulation of gliclazide (GLZ) is required for better patient compliance. This study was conducted to assess the effects of different drug polymer ratios on the release profile of gliclazide from the matrix. Oral matrix tablets of gliclazide were prepared by hot melt method, using pure and blended mixture of glyceryl monostearate (GMS) and stearic acid (SA) in different ratios. In vitro release pattern was studied for 8 h in phosphate buffer media (pH 7.4). Different kinetic models including zero order, first order, Higuchi and Peppas were applied to evaluate drug release behavior. Drug excipient compatibility was evaluated by scanning with DSC and FTIR. Higuchi model was found the most appropriate model for describing the release profile of GLZ and non-Fickian release was found predominant mechanism of drug release. The release of drug from the matrix was greatly controlled by GMS while SA appeared to facilitate the release of drug from matrix tablets. FTIR results showed no chemical interaction between drug and the polymers, and DSC results indicated amorphous state of GLZ and polymers without significant complex formation. The results indicate that matrix tablets of gliclazide using glyceryl monostearate and stearic acid showed marked sustained release properties.

Pharmacogenomic analysis of ATP-sensitive potassium channels coexpressing the common type 2 diabetes risk variants E23K and S1369A.

OBJECTIVES: The common ATP-sensitive potassium (KATP) channel variants E23K and S1369A, found in the KCNJ11 and ABCC8 genes, respectively, form a haplotype that is associated with an increased risk for type 2 diabetes. Our previous studies showed that KATP channel inhibition by the A-site sulfonylurea gliclazide was increased in the K23/A1369 haplotype. Therefore, we studied the pharmacogenomics of seven clinically used sulfonylureas and glinides to determine their structure-activity relationships in KATP channels containing either the E23/S1369 nonrisk or K23/A1369 risk haplotypes. RESEARCH DESIGN AND METHODS: The patch-clamp technique was used to determine sulfonylurea and glinide inhibition of recombinant human KATP channels containing either the E23/S1369 or the K23/A1369 haplotype. RESULTS: KATP channels containing the K23/A1369 risk haplotype were significantly less sensitive to inhibition by tolbutamide, chlorpropamide, and glimepiride (IC50 values for K23/A1369 vs. E23/S1369=1.15 vs. 0.71 µmol/l; 4.19 vs. 3.04 µmol/l; 4.38 vs. 2.41 nmol/l, respectively). In contrast, KATP channels containing the K23/A1369 haplotype were significantly more sensitive to inhibition by mitiglinide (IC50=9.73 vs. 28.19 nmol/l for K23/A1369 vs. E23/S1369) and gliclazide. Nateglinide, glipizide, and glibenclamide showed similar inhibitory profiles in KATP channels containing either haplotype. CONCLUSION: Our results demonstrate that the ring-fused pyrrole moiety in several A-site drugs likely underlies the observed inhibitory potency of these drugs on KATP channels containing the K23/A1369 risk haplotype. It may therefore be possible to tailor existing therapy or design novel drugs that display an increased efficacy in type 2 diabetes patients homozygous for these common KATP channel haplotypes.

Adverse cardiovascular events during treatment with glyburide (glibenclamide) or gliclazide in a high-risk population.

AIMS: Sulphonylureas promote insulin release by inhibiting pancreatic potassium channels. Older sulphonylureas such as glyburide (glibenclamide), but not newer ones such as gliclazide, antagonize similar channels in myocardium, interfering with the protective effects of ischaemic preconditioning. Whether this imparts a higher risk of adverse cardiac events is unknown. METHODS: We conducted a population-based cohort study of patients aged 66 years and older who were hospitalized for acute myocardial infarction or who underwent percutaneous coronary intervention between 1 April 2007 and 31 March 2010 while receiving either glyburide or gliclazide. We used a high-dimensional propensity score matching process to ensure similarity of glyburide- and gliclazide-treated patients. The primary outcome was a composite of death or hospitalization for myocardial infarction or heart failure. RESULTS: During the 2-year study period, we matched 1690 patients treated with glyburide to 984 patients treated with gliclazide at the time of hospitalization for acute myocardial infarction or percutaneous coronary intervention. We found no difference in the risk of the composite outcome among patients receiving glyburide (adjusted hazard ratio 1.01; 95% CI 0.86-1.18). We found similar results in secondary analyses of each outcome individually, and in two supplementary analyses (haemorrhage and pneumonia) in which we anticipated no difference between the two patient groups. CONCLUSIONS: Among older patients hospitalized for acute myocardial infarction or percutaneous coronary intervention, treatment with glyburide is not associated with an increased risk of future adverse cardiovascular events relative to gliclazide, suggesting that the effect of glyburide on ischaemic preconditioning is of little clinical relevance.

Protective effects of combined therapy of gliclazide with curcumin in experimental diabetic neuropathy in rats.

Diabetic neuropathy is the most common chronic complication of diabetes. The aim of the present study was to evaluate the protective effects of curcumin against neuropathy in gliclazide-treated diabetic rats. Diabetes was induced by an intraperitoneal injection of streptozotocin (45 mg/kg). Diabetic animals were given gliclazide (10 mg/kg, orally) alone or combined with curcumin (100 mg/kg, orally) or gabapentin (30 mg/kg, intraperitoneally as a positive control). Behavioral responses to thermal (hot plate and tail flick) and mechanical (tail pinch) pain, and some biochemical tests (serum glucose, C-peptide, peroxynitrite, lipid peroxides, and tumor necrosis factor-α) were assessed after 5 consecutive weeks of daily treatment. Combined treatment of curcumin with gliclazide significantly increased hot-plate and tail-flick latencies in comparison with that of the diabetic control group. The threshold of mechanical hyperalgesia was also significantly elevated. Serum glucose and C-peptide levels were significantly increased in the combined treatment compared with the diabetic control group, whereas serum levels of peroxynitrite, lipid peroxide, and tumor necrosis factor-α production were significantly decreased. The data suggest that the combination of curcumin with gliclazide may protect against the development of diabetic neuropathy, with favorable effects with respect to the gliclazide/gabapentin combination.