Development of a Robust Control Strategy for Fixed-Dose Combination Bilayer Tablets with Integrated Quality by Design, Statistical, and Process Analytical Technology Approach.

Control strategy and quality by design (QbD) are widely used to develop pharmaceutical products and improve drug quality; however, studies on fixed-dose combination (FDC) bilayer tablets are limited. In this study, the bilayer tablet consisted of high-dose metformin HCl in a sustained-release layer and low-dose dapagliflozin l-proline in an immediate-release layer. The formulation and process of each layer were optimized using the QbD approach. A d-optimal mixture design and response surface design were applied to optimize critical material attributes and critical process parameters, respectively. The robust design space was developed using Monte Carlo simulations by evaluating the risk of uncertainty in the model predictions. Multivariate analysis showed that there were significant correlations among impeller speed, massing time, granule bulk density, and dissolution in the metformin HCl layer, and among roller pressure, ribbon density, and dissolution in the dapagliflozin l-proline layer. Process analytical technology (PAT) was used with in-line transmittance near-infrared spectroscopy to confirm the bulk and ribbon densities of the optimized bilayer tablet. Moreover, the in vitro drug release and in vivo pharmacokinetic studies showed that the optimized test drug was bioequivalent to the reference drug. This study suggested that integrated QbD, statistical, and PAT approaches can develop a robust control strategy for FDC bilayer tablets by implementing real-time release testing based on the relationships among various variables.

Physicochemical characterization of dapagliflozin and its solid-state behavior in stress stability test.

As an active pharmaceutical ingredient, dapagliflozin propanediol monohydrate (D-PD) has been used in the solvated form consisting of dapagliflozin compounded with (S)-propylene glycol and monohydrate at a 1:1:1 ratio. However, dapagliflozin propanediol loses the solvent's reduced lattice structure at slightly higher temperatures. Due to its sensitive solid-state stability, the temperature and humidity are strictly controlled during the production and storage of dapagliflozin. Thus, crystalline molecular complexes containing pharmaceutical salts, solvates, monohydrates, and cocrystals have recently been developed as alternative strategies. This study investigated the dapagliflozin free base (D-FB), D-PD, and dapagliflozin l-proline cocrystals (D-LP). Their solid-state behavior was also evaluated in stress stability studies. The compounds were analyzed using scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR) spectroscopy, dynamic vapor sorption (DVS), and powder rheology testing. In addition, Carr's index, the Hausner ratio, contact angle, and intrinsic dissolution rate were calculated. Dapagliflozin exhibited distinct physical properties depending upon the differences in solid form and also showed significant differences in solid-state behavior in the stress stability test. In conclusion, D-LP was superior to D-FB or D-PD in physicochemical and mechanical properties.

Control Strategy for Process Development of High-Shear Wet Granulation and Roller Compaction to Prepare a Combination Drug Using Integrated Quality by Design.

In this study, we developed a control strategy for a drug product prepared by high-shear wet granulation and roller compaction using integrated quality by design (QbD). During the first and second stages, we optimized the process parameters through the design of experiments and identified the intermediate quality attributes (IQAs) and critical quality attributes (CQAs) relationship, respectively. In the first stage, we conducted an initial risk assessment by selecting critical process parameters with high impact on IQAs and CQAs and confirmed the correlation between control and response factors. Additionally, we performed Monte Carlo simulations by optimizing the process parameters to deriving and building a robust design space. In the second stage, we identified the IQAs and CQAs relationship for the control strategy, using multivariate analysis (MVA). Based on MVA, in the metformin layer, dissolution at 1 h was significantly correlated with intrinsic dissolution rate and granule size, and dissolution at 3 h was significantly correlated with bulk density and granule size. In dapagliflozin layer, dissolution at 10 min and 15 min was significantly correlated with granule size. Our results suggest that the desired drug quality may result through IQAs monitoring during the process and that the integrated QbD approach utilizing MVA can be used to develop a control strategy for producing high-quality drug products.

Preparation and characterization of metformin hydrochloride controlled-release tablet using fatty acid coated granules.

Metformin hydrochloride (MFM) is often used as a controlled-release (CR) tablet to reduce dosing frequency. However, the MFM CR tablet contains significant amounts of excipients and the tablet size is also large. Dosing convenience and patient compliance can be increased by reducing the size of the CR tablets. The aim of this study was to prepare and evaluate the MFM controlled-release tablet (MFM-CRT) using two types of release modulators, inner and outer. The MFM-CRT was prepared by coating the MFM granules using a binder solution containing aluminum stearate (ALS) as the inner release-modulator, and polyethylene oxide (PEO) as the outer release-modulator. The dispersion stability of the binder solution was optimized by the dispersion analyzer. The MFM-CRT was evaluated for dissolution rate and tablet volume. Additionally, dissolution behavior and dissolution kinetics of the MFM-CRT were analyzed using micro-computed tomography (micro-CT). Although the optimal MFM-CRT showed no difference in the release rate as compared to the commercially available product of Glucophage® XR 500 mg (f2 value: 72), the length of the long axis was reduced by 6 mm and the weight was reduced by about 27%. We expect patient compliance to improve because of effective sustained release and volume reduction of MFM-CRT.

Diastereoselective synthesis of anti-1,2-aminoalcohol by palladium(II) catalyzed aza-Claisen rearrangement.

In this study, a highly diastereoselective synthesis of anti-1,2-aminoalcohol was explored starting from L-amino acids as chiral sources. The higher yield and diastereoselectivity was shown when the aza-Claisen rearrangement was performed with allylic trichloroacetimidate 6a in the presence of palladium(II) catalyst.