Pharmacodynamic comparison of two formulations of Acarbose 100-mg tablets

Evaluation of Acarbose Bioequivalence in Healthy Chinese Populations Using Novel Pharmacodynamic End Points

Acarbose is a widely used α-glucosidase inhibitor for the management of postprandial hyperglycemia in patients with type 2 diabetes mellitus. Recent pilot studies on acarbose bioequivalence (BE) have successfully identified additional pharmacodynamic (PD) parameters as valid end points. Nevertheless, there was a scarcity of published pivotal studies using novel PD parameters. The purpose of the study is to investigate the acarbose BE using the new PD parameters. The study was conducted with an open, randomized, 2-period crossover design. A total of 64 healthy Chinese volunteers received either the reference (R) or test (T) acarbose at a dose of 2×50 mg orally, followed by a 1-week washout period. After sucrose treatment (baseline) and sucrose/acarbose co-administration, serum glucose, and insulin concentrations were assessed. The rectifying approach yielded geometric mean ratios of 102.9% for maximum serum glucose concentration with deduction of glucose concentration at 0 hour and 105.3% for the area under the serum glucose concentration-time curve profile 0-2 hours after coadministration of sucrose and acarbose with deduction of baseline (AUC0-2 h,r ). The 90% confidence intervals of maximum serum glucose concentration with deduction of glucose concentration at 0 hour and the area under the serum glucose concentration-time curve profile 0-2 hours after coadministration of sucrose and acarbose with deduction of baseline all fell within the acceptance limits. The incidence of adverse events after the T or R drug was comparable, and healthy subjects were well tolerated. The findings of our investigation clearly show that the PD parameters of the rectifying method exhibit enhanced suitability and sensitivity when assessing acarbose BE in healthy participants. The T and R drugs were bioequivalent using the novel PD parameters, and both drugs demonstrated good safety and tolerability.

Bioequivalence Study of Miglitol Orally Disintegrating Tablets in Healthy Chinese Volunteers Under Fasting Condition Based on Pharmacodynamic and Pharmacokinetic Parameters

To investigate the bioequivalence of miglitol orally disintegrating tablets in healthy Chinese volunteers based on pharmacodynamic (PD) and pharmacokinetic (PK) parameters. Additionally, the safety profile was estimated. Two randomized, open-label, single-dose, crossover trials were conducted under fasting conditions. In the PD trial (CTR20191811), 45 healthy volunteers were randomly divided into 3 groups in a 1:1:1 ratio and administered sucrose alone or coadministered with 50 mg of miglitol orally disintegrating tablet test or reference formulation/sucrose. In the PK trial (CTR20191696), 24 healthy volunteers were randomized (1:1) to receive the test or reference formulation (50 mg). Blood samples were collected at 15 and 17 sampling points per cycle in the PD and PK trials, respectively. Plasma miglitol and serum glucose concentrations were analyzed using a validated liquid chromatography-tandem mass spectrometry method. Serum insulin concentrations were measured using electrochemiluminescent immunoassay. Statistical analyses for the PD and PK parameters were subsequently performed. The volunteers' physical indicators were monitored and documented during the entire study to estimate drug safety. The PD and PK parameters of the two formulations were similar. The main PD and PK end points were both within the prespecified range of 80%-125%. The incidences of treatment-emergent adverse events (TEAEs) and drug-related TEAEs were similar between the test and reference formulation groups, and no serious TEAEs or deaths occurred during the 2 trials. These 2 formulations were demonstrated to be bioequivalent and well tolerated in healthy Chinese volunteers under fasting condition.

Bioequivalence Evaluation Between Acarbose and Metformin Fixed-Dose Combination and Corresponding Individual Components in Healthy Chinese Male and Female Subjects

Acarbose and metformin have been recommended both as monotherapy and add-on therapy in type 2 diabetes mellitus. A novel fixed-dose combination (FDC) of acarbose and metformin has been developed to improve compliance and patient adherence to therapy. The current study investigated the bioequivalence (BE) between acarbose/metformin FDC (50 mg/500 mg) with corresponding loose combination of individual components under fasting conditions in healthy Chinese male and female subjects, using a randomized, 2-period, 2-way crossover study design. Pharmacodynamic parameters of serum glucose ratio between treatment day and baseline (ratio of maximum concentration [C_max ], day 1/C_max , day -1 and ratio of area under the concentration-time curve [AUC] from time 0 to 4 hours, day 1/AUC from time 0 to 4 hours, day -1) were used as the primary variables to evaluate BE of acarbose. Pharmacokinetic parameters C_max , AUC from time 0 to the last data point greater than the lower limit of quantification, and AUC were used to evaluate BE of metformin. The results showed that the 90% confidence intervals of the ratios of all primary target variables including ratio of C_max , day 1/C_max , day -1 and ratio of AUC from time 0 to 4 hours, day 1/AUC from time 0 to 4 hours, day -1 for acarbose, and C_max , AUC from time 0 to the last data point greater than the lower limit of quantification, and AUC for metformin all fell within the acceptance limits of 0.8 to 1.25. Thus, BE between 50-mg acarbose and 500-mg metformin as an FDC and loose combination was established. Furthermore, different kinds of exploratory pharmacodynamic parameters (based on either serum glucose or insulin) including several newly proposed parameters were also investigated for acarbose BE evaluation in this study, and inconsistent results were observed.

Evaluation of the Bioequivalence of Acarbose in Healthy Chinese People

The purpose of this study was to determine whether the reference formulation and test formulation of acarbose are bioequivalent among healthy Chinese subjects based on evaluation of the pharmacodynamic end point. Two clinical trials with acarbose were conducted: study A, a pilot study (n = 12; 50 and 100 mg), and study B, a pivotal study (n = 60; 50 mg). In study A, there was a dose‐dependent relationship between 50 mg acarbose and 100 mg acarbose and a significant difference compared with sucrose alone. In study B, after logarithmic conversion, a linear mixed‐effects model was used to analyze the maximum serum glucose value and area under the serum glucose‐time curve from 0 to 2 hours. The geometric mean ratios (test formulation/reference formulation) were 92.68% and 95.70%, with 90% confidence intervals of 84.08%‐102.17% and 84.21%‐108.76%, respectively, falling between 80.00% and 125.00%. According to the geometric least‐squares mean, the test formulation (or reference formulation) was statistically significantly different as a single sucrose (P < .001). The effective dose of acarbose in healthy Chinese volunteers was 50 mg. The reference and test formulations were bioequivalent.

Pharmacodynamic comparison of acarbose tablets in Chinese healthy volunteers under chewing and swallowing conditions

WHAT IS KNOWN AND OBJECTIVE

Acarbose can efficiently block glucose absorption in the intestine as an alpha-glucosidase inhibitor. It is currently manufactured in several oral dosage forms, with the most common types being tablets and chewable tablets. The acarbose tablet (Glucobay^® , 50 mg, Bayer) package insert gives instructions for either directly swallowing or chewing then swallowing. This study compared the pharmacodynamic effects of a single formulation of acarbose tablets under these two different administration routes.

METHODS

This randomized, crossover study enrolled 24 healthy subjects who were instructed to chew (C group) or swallow (S group) the acarbose tablet. Glucose levels were monitored in subjects for up to 4 h following administration of 75 g of sucrose to establish a baseline firstly, after which subjects in the C and S groups were administered 50- or 100- mg of acarbose along with 75 g of sucrose. Then, subjects entered a 1-week washout period before being crossed over to the alternate dosing route.

RESULTS AND DISCUSSION

Compared with the S group, the C group had a lower maximum concentration of serum glucose (C_max ) and areas under the concentration-time curve (AUC_0-2 , AUC_0-1.5 ). In addition, the maximum reduction in serum glucose (ΔC_max ) and the reduction in the AUC (AUEC_0-1.5 ) were both increased in the S group. This occurred at both the 50 mg and 100 mg dosages. These results indicate that fluctuations in blood glucose were lower following chewing of the acarbose tablet. Both administration routes exhibited similar safety and tolerance profiles.

WHAT IS NEW AND CONCLUSION

In summary, chewing acarbose tablets appears to induce a superior glycaemic-controlling effect compared with swallowing them directly, at least with a single dose. It will be important to inform both clinicians and patients about these differences between the two administrations so that informed clinical decisions can be made, as numerous patients with diabetes are inclined to directly swallow acarbose tablets for convenience.

A comparative study of acarbose, vildagliptin and saxagliptin intended for better efficacy and safety on type 2 diabetes mellitus treatment

As a complicated metabolic disorder, type 2 diabetes mellitus (T2DM) is becoming a major health concern worldwide. Drugs including acarbose, saxagliptin and vildagliptin are applied, but their efficacy is still required to be compared. Therefore, the study aimed to evaluate the efficacy and safety of acarbose, saxagliptin and vildagliptin in the treatment of T2DM. Ninety patients diagnosed with T2DM were treated with acarbose, saxagliptin and vildagliptin, respectively (30 patients for each drug). All patients were examined at 0, 4 and 12 weeks after treatment with vital signs recorded. Fasting blood glucose and blood biochemical indices were analyzed. In addition, fecal samples were taken for microbial macrogenome sequencing and safety evaluation within 12 weeks after treatment. Blood glucose level decreased at 4 and 12 weeks after treatment, and the total cholesterol (TC) and high-density lipoprotein (HDL) levels at 12 weeks were different. Genus abundance of intestinal flora was altered at different time points. Acarbose increased Butyricimonas level first and then decreased it during drug treatment. Saxagliptin increased Megamonas and decreased Turicibacter genus level gradually. Pseudomonas, Klebsiella, Blautia, Faecalibacterium and Roseburia levels fluctuated after Vildagliptin treatment, which increased fasting C-peptide level greater than the other two drugs. Saxagliptin showed higher adverse reactions than acarbose and vildagliptin. Collectively, acarbose, vildagliptin, and saxagliptin can effectively reduce the HbA1c level and affect the intestinal flora distribution in T2DM patients, and the adverse reactions of acarbose and vildagliptin are less than saxagliptin, providing alternative strategies for the treatment of T2DM.

Acarbose bioequivalence: Exploration of eligible protocol design

WHAT IS KNOWN AND OBJECTIVE

Acarbose is a poorly absorbed α-glucosidase inhibitor that acts locally in the intestinal tract. Therefore, the evaluation of its bioequivalence (BE) should be based on pharmacodynamic (PD) rather than pharmacokinetic (PK) endpoints. Currently, there is no consensus on the best method for acarbose BE evaluation. The optimal protocol design regarding dosing time/dose and PD parameters requires further exploration. The aim of the study was to identify an optimum protocol for establishing acarbose BE in healthy Chinese volunteers using PD endpoints.

METHODS

Three pilot studies were conducted in healthy Chinese subjects. Study 1 was an open, randomized, two-period crossover study using the reference (R) drug at the dose of 1 × 50 mg. Study 1 aimed to determine appropriate dosing time by comparing the PD effect of acarbose between two administration methods. One method was concomitant administration of sucrose and acarbose, and another method was acarbose administration 10 min before sucrose. Study 2 was an open, randomized, three-period crossover study. Subjects were given the R drug at the dose of 1 × 50 mg, 2 × 50 mg or 3 × 50 mg in a random sequence. The aim of Study 2 was to identify a reasonable dose of acarbose in the BE study. Study 3 was conducted with an open, randomized, three-period crossover design using the test (T) or R drug in an R-T-R sequence at the dose of 2 × 50 mg. Study 3 aimed to compare the BE between the R and T drug and determine intra-individual variation. Twelve subjects were recruited in Study 1, Study 2 and Study 3, respectively, with a one-week washout period. Serum glucose and insulin concentrations were determined after sucrose administration (baseline) and sucrose/acarbose co-administration.

RESULTS AND DISCUSSION

In Study 1, no significant differences in PD parameters were found between the two administration methods. The results of Study 2 revealed that the optimal dose was between 1 × 50 mg and 2 × 50 mg. The comparison of PD parameters indicated that the rectifying method could distinguish between different formulations. Study 3 showed that the geometric mean ratios of C_{max, r} , AUC_{0-2 h, r} and AUC_{0-4 h, r} were 90.06%, 84.55% and 84.21%, respectively, using the rectifying method. The 90% CIs of C_{max, r} were within acceptance limits (80.00%-125.00%), whereas that of AUC_{0-2 h, r} and AUC_{0-4 h, r} were out of the range. The intra-individual variation was approximately 21% for R formulation. Based on the variation, the number of subjects needed to identify formulation differences in the pivotal study would be 55 with 90% power at the 5% level of significance.

WHAT IS NEW AND CONCLUSION

The results from our study manifested that a randomized, balanced, two-way crossover design was eligible to evaluate acarbose BE. The appropriate dosing time was concomitant administration of sucrose and acarbose, and the optimal dose was 2 × 50 mg. The rectifying method exhibited preferable sensitivity and applicability in acarbose BE evaluation. A practical sample size of the pivotal study would be 55. These results may help to provide new insights into the protocol design of acarbose BE study.

Bioequivalence and Evaluation Parameters Based on the Pharmacodynamics of Miglitol in Healthy Volunteers

The aim of this study was to explore the bioequivalence of miglitol based on pharmacodynamic properties. The study was performed as a single-dose, randomized, open-label, 3-period, 3-way crossover trial over a 7-day washout period. Forty-eight subjects were randomly assigned into 3 groups: (1) miglitol test formulation/sucrose coadministration, (2) miglitol reference formulation/sucrose coadministration, and (3) sucrose administration alone. Serum glucose concentrations were measured by the hexokinase detection method. The peak serum glucose concentration (C_max ) and the area under the serum glucose concentration-time curve through 4 hours (AUC_0-4h ) were used as the main pharmacodynamic parameters to evaluate bioequivalence. The 90% confidence intervals for the geometric mean ratios of C_max and AUC_0-4h were 94.81%-101.07% and 98.82%-100.72%, respectively, which were all within the bioequivalence range of 80.00%-125.00%. The test and reference formulations of miglitol were pharmacodynamically bioequivalent during the trial.

Method for evaluating the human bioequivalence of acarbose based on pharmacodynamic parameters

Objective

To explore a method for evaluating the bioequivalence of acarbose based on pharmacodynamic parameters using a single-dose, randomized-sequence, three-way crossover study of acarbose test (T) and reference (R) formulations.

Methods

Baseline-adjusted, pre-dose value deduction, and direct comparison methods were used to evaluate the geometric T/R ratios and 90% confidence intervals (CIs) of the ln-transformed pharmacodynamic parameters to identify the most suitable evaluation system. Twelve participants were randomly divided into three groups to receive treatment in the following sequences: TRR, RTR, and RRT, each including a 7-day washout period between treatment periods. The serum glucose concentration (baseline) was determined. Pharmacodynamic parameters, including the maximum reduction in serum glucose concentrations (ΔC_SG,max) and difference of the AUC of glucose between before and after acarbose exposure (ΔAUEC), were tested.

Results

Using the direct comparison method, the geometric mean ratios of C_SG,max, AUEC_(0-2h), and AUEC_(0-4h) were 94.13%, 97.82% and 99.76%, respectively. The 90% CIs of the geometric T/R ratios for C_SG,max, AUEC_(0-2h), and AUEC_(0-4h) all fell between 80% and 125%. Conversely, ΔC_SG,max and ΔAUEC_(0-4h) were less reliable measures of acarbose bioequivalence.

Conclusions

Pre-dose value deduction and direct comparison methods can be initially considered suitable for assessing acarbose bioequivalence.

Exploration of suitable pharmacodynamic parameters for acarbose bioequivalence evaluation: A series of clinical trials with branded acarbose

Aims

To determine deficiencies in the Food and Drug Administration (FDA)'s guidance for assessing acarbose bioequivalence (BE) and to explore optimal pharmacodynamic (PD) metrics for better evaluation of acarbose BE.

Methods

Three clinical trials with branded acarbose were conducted in healthy subjects, including a pilot study (Study I, n = 11, 50 and 100 mg), a 2×2 crossover BE study (Study II, n = 36, 100 mg) and a 4×4 Williams study (Study III, n = 16, 50/100/150 mg). Serum glucose concentrations were measured by the glucose oxidase method.

Results

In Study I, compared with 50 mg acarbose, only 100 mg acarbose had a significantly lower C_max0–4h than that of sucrose administration alone (7.96 ± 0.83 mmol/L vs 6.78 ± 1.02 mmol/L, P < .05). In Study II, the geometric mean ratios of the test formulation to the reference formulation (both formulations were the branded drug) for FDA PD metrics, ΔC_max0–4h and ΔAUC_0–4h, were 0.903 and 0.776, respectively, and the 90% confidence intervals were 67.44–120.90 and 53.65–112.13, respectively. The geometric mean ratios (confidence interval) for possible optimal evaluation PD metrics (C_max0–2h and AUC_0–2h) were 1.035 (94.23–112.68) and 0.982 (89.28–107.17), respectively. Further, C_max0–2h and AUC_0–2h also met the sensitivity requirements for BE evaluation in Study III.

Conclusion

Considering the mechanisms of action of acarbose, the PD effect was shown to be dose independent during the 2–4 hours postadministration of acarbose. Hence PD metrics based on the serum glucose concentration from 0 to 2 hours (C_max0–2h and AUC_0–2h) are more sensitive than the FDA‐recommended PD metrics for acarbose BE evaluation from 0–4 hours (ΔC_max0–4h and ΔAUC_0–4h).

The trial has been registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn, ChiCTR1800015795, ChiCTR‐IIR‐17013918, ChiCTR‐IIR‐17011903). All subjects provided written informed consent before screening.

Effect of Food Intake on the Pharmacodynamics of Tenapanor: A Phase 1 Study

Tenapanor (RDX5791/AZD1722) is a minimally systemic small-molecule inhibitor of the sodium/hydrogen exchanger NHE3. Tenapanor acts in the gut to reduce absorption of sodium and phosphate. This phase 1 open-label, 3-way crossover study (NCT02226783) evaluated the effect of food on the pharmacodynamics of tenapanor. Eighteen volunteers completed a randomized sequence of three 4-day treatments with tenapanor hydrochloride 15 mg twice daily: before food, after food, and while fasting. Participants received a diet standardized for sodium content. Stool sodium was significantly higher with tenapanor administration before versus after food (difference, +8.8 mmol/day, P = .006) or while fasting (+11.8 mmol/day, P = .0004). Differences in urinary sodium were not significant. Stool phosphorus was not significantly different with tenapanor before versus after food and significantly higher before food versus while fasting (+4.9 mmol/day, P = .006). Urinary phosphorus was significantly lower when tenapanor was administered before (-3.9 mmol/day, P = .0005) or after food (-3.7 mmol/day, P = .0009) versus while fasting. No serious adverse events were reported. These data suggest the effect of tenapanor on sodium absorption is most pronounced when administered before meals, whereas the effect on phosphate is similar whether administered before or after meals. This may support different timings of tenapanor administration with respect to food for sodium- and phosphate-related indications.

Investigation of bioequivalence of a new fixed-dose combination of acarbose and metformin with the corresponding loose combination as well as the drug-drug interaction potential between both drugs in healthy adult male subjects

WHAT IS KNOWN AND OBJECTIVE

Both metformin and acarbose are recommended monotherapy and add-on therapy in type 2 diabetes mellitus (T2DM). A fixed-dose combination (FDC) of acarbose and metformin has been developed to reduce pill burden and potentially improve compliance. The current study investigated the bioequivalence of the acarbose/metformin FDC compared with the individual agents administered simultaneously (loose combination). Secondary endpoints were the safety and tolerability of the FDC and the potential for drug-drug interactions between acarbose and metformin.

METHODS

A single-centre, randomized, open-label, four-period crossover study was conducted in healthy male Korean subjects aged 18-45 years. Following one-period balanced Williams design, participants were randomized to receive four single oral treatments on different study days separated by ≥7 days' washout. Treatments were as follows: (i) acarbose/metformin 50/500 mg FDC (test); (ii) acarbose 50 mg and metformin 500 mg as loose combination (reference); (iii) acarbose 50 mg; and (iv) metformin 500 mg. Serial blood samples were taken for glucose and insulin levels for 4 h after a sucrose load on the day before and day of study drug administration. Additionally, serial blood samples were taken for analysis of metformin levels for 24 h after each drug containing metformin. The area under the curve for 4 h post-test (AUC0-4 h ) and the maximal serum concentration (Cmax ) of plasma glucose and serum insulin were primary pharmacodynamic (PD) parameters, and Cmax , AUC0-last and AUC for metformin levels were primary pharmacokinetic (PK) parameters. The bioequivalence of the FDC to the loose combination was considered established if the 90% confidence intervals (CIs) of the baseline-adjusted PD parameter ratios (test vs. reference) for plasma glucose and the PK parameter ratios for metformin fell completely within current acceptance limits (0·8-1·25).

RESULTS AND DISCUSSION

Thirty-three of 40 randomized subjects completed the study; five withdrew consent and two discontinued because of adverse events (AEs). The 24-h plasma concentration-time curves of metformin and the 4-h plasma glucose-time curves after acarbose/metformin FDC (test) and acarbose + metformin loose combination (reference) were almost superimposable. The geometric least squares (LS) mean of the RatioAUC and RatioCmax for plasma glucose after the FDC vs. loose combination, and the LS mean of the ratios in metformin AUC, AUC0-last and Cmax were close to unity, and the 90% CI of all these parameters fell within the predefined equivalence range of 0·8-1·25, confirming bioequivalence. The metformin AUC was reduced by 26% and Cmax by 34% after acarbose + metformin compared with metformin alone. Eight subjects (20·0%) reported AEs, but all were mild, and most were gastrointestinal, as expected for these agents. The incidence of AEs was not higher with the combinations vs. monotherapy.

WHAT IS NEW AND CONCLUSION

These data demonstrate that the acarbose/metformin FDC is bioequivalent to the loose combination of these agents. Although acarbose slightly reduced the bioavailability of metformin, the accumulated evidence of the efficacy of this combination implies that this is clinically irrelevant. The observed AE profile was consistent with the established knowledge on the safety of the two drugs.