Influence of punch geometry (head-flat diameter) and tooling type ('B' or 'D') on the physical-mechanical properties of formulation tablets.

The presented study assessed the influence of punch geometry (head-flat [HF] diameter) and tooling type ('B' or 'D') on the physical-mechanical properties of tablets prepared by direct-compression of two guaifenesin (25% or 40% w/w) formulations. Tablets of both formulations were prepared on instrumented, single-layer, rotary tablet press using 10 mm, flat-faced, 'B' or 'D'-type tooling with different HF diameters, and compression forces (CF) ranging from 5 to 25 kN with 5 kN increments. The tablets were evaluated for dimensions, weight variation, tensile strength (TS), friability, and capping index. In general, tablets prepared using 'D' tooling showed a significantly (p < 0.05) higher TS compared to those prepared using 'B' tooling, likely due to higher dwell-times associated with 'D' tooling. Formulations containing 25% w/w guaifenesin showed a significantly (p < 0.05) higher TS compared to those containing 40% w/w guaifenesin, at given compression CF, punch geometry, or tooling type. This could be due to the higher ratio of Prosolv® SMCC contributing to the compressibility. For both formulations compressed using 'B' tooling, differences in TS profiles were observed between different HF tooling. The TS of these tablets increased significantly with increasing HF diameter. For formulations compressed using 'D' tooling, this trend was observed only up to a CF of 15 kN, beyond which the TS plateaued, possibly due to work-hardening of the formulation at higher CF. These formulations also exhibited capping at CF above 15 kN and with higher HF diameters. The study showed a significant influence of punch geometry and tooling type on the physical properties of tablets.

A Mechanistic Approach To Model the Compression Cycle of Different Toolings Based on Compression Roller Interactions.

The aim of the current work was to model and understand the mechanical interactions of tooling heads with compression rollers during tableting. Binary direct compression blends of Prosolv® SMCC with 0.5% w/w magnesium stearate and ternary blends with 30% w/w acetaminophen were used. Tablet compression was performed using an instrumented Riva Piccola press with 10 mm round flat face D- and B-type TSM domed punches. Five punches were used for the study with varying dimensions of head flats. Strain rate studies were carried out at 12.5, 25, 50, and 75 revolutions of turret per minute (RPM) and a compaction profile was performed at compression pressures of 50, 100, 150, and 200 MPa. Tablet weight, thickness, and tensile strength were evaluated. Compression raw data was used to model the punch interactions. A MATLAB program was created to model the head profiles based on their dimensions, punch tip separation, vertical velocity, and pitch circle diameter of the press. Tablets compressed with no head flats were the weakest and showed less strain rate sensitivity. Tensile strengths increased linearly with the head flat dimensions. Also, difference in loading times due to roll movement during compression was evaluated. Capping was observed in tablets compressed at 75 RPM from the ternary blend containing 30% acetaminophen. However, punches with zero head flat showed no capping at these speeds. Also, B-type tooling showed relatively less capping tendency. This work shows that dwell time effect on tablet properties is based on the punch head flat region and the punch head interactions with the rollers.

Fusion Method for Solubility and Dissolution Rate Enhancement of Ibuprofen Using Block Copolymer Poloxamer 407.

Aim of current research was to prepare ibuprofen-poloxamer 407 binary mixtures using fusion method and characterize them for their physicochemical and performance properties. Binary mixtures of ibuprofen and poloxamer were prepared in three different ratios (1:0.25, 1:0.5, and 1:0.75, respectively) using a water-jacketed high shear mixer. In vitro dissolution and saturation solubility studies were carried out for the drug, physical mixtures, and formulations for all ratios in de-ionized water, 0.1 N HCl (pH = 1.2), and phosphate buffer (pH = 7.2). Thermal and physical characterization of samples was done using modulated differential scanning calorimetry (mDSC), X-ray powder diffraction (XRD), and infrared spectroscopy (FTIR). Flow properties were evaluated using a powder rheometer. Maximum solubility enhancement was seen in acidic media for fused formulations where the ratio 1:0.75 had 18-fold increase. In vitro dissolution studies showed dissolution rate enhancement for physical mixtures and the formulations in all three media. The most pronounced effect was seen for formulation (1:0.75) in acidic media where the cumulative drug release was 58.27% while for drug, it was 3.67%. Model independent statistical methods and ANOVA based methods were used to check the significance of difference in the dissolution profiles. Thermograms from mDSC showed a characteristic peak for all formulations with Tpeak of around 45°C which suggested formation of a eutectic mixture. XRD data displayed that crystalline nature of ibuprofen was intact in the formulations. This work shows the effect of eutectic formation and micellar solubilization between ibuprofen and poloxamer at the given ratios on its solubility and dissolution rate enhancement.