Study of standard tablet formulation based on fluidized-bed granulation

Comprehensive Study of Intermediate and Critical Quality Attributes for Process Control of High-Shear Wet Granulation Using Multivariate Analysis and The Quality by Design Approach

A robust manufacturing process and the relationship between intermediate quality attributes (IQAs), critical quality attributes (CQAs), and critical process parameters (CPPs) for high-shear wet granulation was determined in this study. Based on quality by the design (QbD) approach, IQAs, CQAs, and CPPs of a telmisartan tablet prepared by high-shear wet granulation were determined and then analyzed with multivariate analysis (MVA) to evaluate mutual interactions between IQAs, CQAs, and CPPs. The effects of the CPPs on the IQAs and CQAs were quantitatively predicted with empirical models of best fit. The models were used to define operating space, and an evaluation of the risk of uncertainty in model prediction was performed using Monte Carlo simulation. MVA showed that granule size and granule hardness were significantly related to % dissolution. In addition, granule FE (Flow Energy) and Carr's index had effects on tablet tensile strength. Using the manufacture of a clinical batch and robustness testing, a scale-up from lab to pilot scale was performed using geometric similarity, agitator torque profile, and agitator tip speed. The absolute biases and relative bias percentages of the IQAs and CQAs generated by the lab and pilot scale process exhibited small differences. Therefore, the results suggest that a risk reduction in the manufacturing process can be obtained with integrated process parameters as a result of the QbD approach, and the relationship between IQAs, CQAs, and CPPs can be used to predict CQAs for a control strategy and SUPAC (Scale-Up and Post-Approval Guidance).

Near-infrared spectroscopy monitoring and control of the fluidized bed granulation and coating processes-A review

The fluidized bed granulation and pellets coating technologies are widely used in pharmaceutical industry, because the particles made in a fluidized bed have good flowability, compressibility, and the coating thickness of pellets are homogeneous. With the popularization of process analytical technology (PAT), real-time analysis for critical quality attributes (CQA) was getting more attention. Near-infrared (NIR) spectroscopy, as a PAT tool, could realize the real-time monitoring and control during the granulating and coating processes, which could optimize the manufacturing processes. This article reviewed the application of NIR spectroscopy in CQA (moisture content, particle size and tablet/pellet thickness) monitoring during fluidized bed granulation and coating processes. Through this review, we would like to provide references for realizing automated control and intelligent production in fluidized bed granulation and pellets coating of pharmaceutical industry.

A new formulation for orally disintegrating tablets using a suspension spray-coating method

The aim of this study was to design a new orally disintegrating tablet (ODT) that has high tablet hardness and a fast oral disintegration rate using a new preparation method. To obtain rapid disintegration granules (RDGs), a saccharide, such as trehalose, mannitol, or lactose, was spray-coated with a suspension of corn starch using a fluidized-bed granulator (suspension method). As an additional disintegrant, crospovidone, light anhydrous silicic acid, or hydroxypropyl starch was also included in the suspension. The RDGs obtained possessed extremely large surface areas, narrow particle size distribution, and numerous micro-pores. When tabletting these RDGs, it was found that the RDGs increased tablet hardness by decreasing plastic deformation and increasing the contact frequency between granules. In all tablets, a linear relationship was observed between tablet hardness and oral disintegration time. From each linear correlation line, a slope (D/H value) and an intercept (D/H(0) value) were calculated. Tablets with small D/H and D/H(0) values could disintegrate immediately in the oral cavity regardless of the tablet hardness and were considered to be appropriate for ODTs. Therefore, these values were used as key parameters to select better ODTs. Of all the RDGs prepared in this study, mannitol spray-coated with a suspension of corn starch and crospovidone (2.5:1 w/w ratio) showed most appropriate properties for ODTs; fast in vivo oral disintegration time, and high tablet hardness. In conclusion, this simple method to prepare superior formulations for new ODTs was established by spray-coating mannitol with a suspension of appropriate disintegrants.

The Influence of Formulation on the Dissolution Profile of Diclofenac Sodium Tablets

In attempts to design delayed-release tablets of diclofenac sodium, seven experimental batches were produced. The influence of super-disintegrant croscarmellose sodium (CCS), the granulation process, and the thickness of Eudragit L 100 coating film were evaluated. The values of dissolution efficiency and the similarity factor were used to compare the dissolution profiles of each experimental batch and the reference Voltaren. Both methods appear to be applicable and useful in comparing dissolution profiles. Based on such values four batches were considered similar when contrasted with the reference. The results suggest an optimal relationship between the amount of CCS and the thickness of the coating film, which provides appropriate dissolution rate of diclofenac sodium from the dosage forms.

Influence of loading volume of mefenamic acid on granules and tablet characteristics using a compaction simulator

Mefenamic acid (MA), a poorly water-soluble drug, was used as a model substance to investigate granules and tablet characteristics to be optimized for the loading volume of MA (0-74.1% v/v) in the formulation including lactose monohydrate/maize starch (7/3) as excipients. The compactibility of granules increased with loading volume of MA. This was related to the brittle behavior of MA during compression and the increase of intragranular pore volume of granules. The minimum disintegration time (266+/-8.3 s) was found in the tablet that was composed of 55.1% v/v MA and 13.6% v/v maize starch. The determination of the critical concentration of disintegrant (% v/v) required for a minimum disintegration time is suggested to be useful for solid dosage form design.

Effect of crystallization behavior of polyethylene glycol 6000 on the properties of granules prepared by fluidized hot-melt granulation (FHMG)

The objective of this study was to investigate the effect of the crystallization behavior of Macrogol 6000 (polyethylene glycol 6000; PEG 6000), used as a binder, during the solidification process on the properties of mononucleic granules prepared by the fluidized hot-melt granulation (FHMG) technique. Crystallization of PEG 6000 from molten liquid was investigated using differential scanning calorimetry (DSC) and hot stage microscopy. The results obtained from the measurement of isothermal crystallization demonstrated that crystallization of PEG 6000 was either slow or rapid. Analysis based on solid-state decomposition showed that slow crystallization was due to the two-dimensional growth of nuclei mechanism, while rapid crystallization was due to the three-dimensional growth of nuclei mechanism. Observation of the crystallization of PEG 6000 by hot stage microscopy supported the existence of two different crystallization mechanisms. Granules containing PEG 6000 that underwent rapid crystallization during FHMG showed a significantly higher fraction powder under 150 microm in diameter. This was caused by the loss of powder particles from the surface of mononucleic granules during the solidification process, because many cracks were observed after crystallization of PEG 6000 with a short isothermal crystallization time (ICT) due to the reduced of sticking of particles. The results of this study suggested that the crystallization behavior of the binder during the solidification process of FHMG can influence the properties of the resultant granules, such as particle size distribution, content uniformity or taste masking. It was also indicated that measuring the ICT using DSC was a useful method to classify PEG 6000.

Comparative evaluation of granules made with different binders by a fluidized bed method

Granules were prepared using three different binders, pregelatinized starch (PGS), gelatin (GEL), and polyvinylpyrrolidone (K30) by a fluidized bed method. As a quantitative measurement of mechanical strength or abrasion resistance, granules were subjected to a friability test for certain periods of time, and friability indexes (FI) as a function of time were calculated. The data obtained were analyzed by applying standard mathematical models. According to the derived parameters of the logistic and Weibull models, which fit best to the data, mechanical strength of granules made with K30 was observed to be lower than that of the granules of PGS and GEL which have similar values of model parameters. Flow properties, consolidation, and compressibility behaviors of unfriabled (UFR) and friabled (FR) granules, which were selected based upon their Weibull time parameter, were investigated as comparative. The flow rate of granules decreased due to diminishing particle size depending on binder type and friability, but the values of angle of repose were within the acceptable limits. Regarding consolidation behavior, the change of relative density vs. the number of taps, i.e., packing rate for FR granules of GEL was slower than that of its UFR form, whereas FR granules of PGS and K30 showed faster change in relative density compared to their UFR forms. According to the parameters obtained from the Heckel equation, PGS and K30 were found to produce softer, more plastic and readily deformable granules than GEL, and the compressibility of their FR forms was not influenced negatively.

Fluid bed granulation of a poorly water soluble, low density, micronized drug: comparison with high shear granulation

A 2(4-1) fractional factorial design was used to evaluate the effect of various process variables in fluid bed granulation, on the physico-chemical properties of granule and tablet containing a high dose, poorly water soluble, low density, and micronized drug. The process variables studied were inlet air temperature, inlet air flow, spray rate of the binder solution, and atomization air pressure. Tablets with identical composition, weight, size and hardness were also manufactured in a high shear granulator and their physical properties were determined and compared with those produced by the fluidized bed granulation method. Except for the granule size distribution, other physical properties of granulations and tablets produced in a fluid bed granulator are independent of the selected process variables within the study range. Both atomization air pressure and spray rate of the binder solution had strong impact on granule size distribution. Irrespective of the process conditions used in the fluid bed granulation, granules from this process were more porous, less dense and more compressible than the granules from the high shear granulation process. Comparable tablet dissolution rates to those prepared by the optimized high shear granulation method can be achieved by selecting the appropriate process conditions in fluid bed granulation. These results suggest that wet granulation tablets of a high dose, poorly water soluble, low density, micronized drug can be manufactured using a fluidized bed granulation method, with comparable tablet dissolution rates to those produced with an optimized high shear granulation method.

Application of fluidized hot-melt granulation (FHMG) for the preparation of granules for tableting; properties of granules and tablets prepared by FHMG

The objective of this study was to investigate the properties of granules and tablets prepared by a novel Fluidized Hot-Melt Granulation (FHMG) technique. Macrogol 6000 (polyethylene glycol 6000, PEG 6000), macrogol 20000 (polyethylene glycol 20000, PEG 20000), and glyceryl monostearate (GMS) were used as binders with different levels of viscosity and water solubility. The properties of both granules and tablets were compared with those obtained using the Standard Tablet Formulation (STF, lactose/corn starch/hydroxypropylcellulose/ magnesium stearate: 66/30/3.5/0.5) for fluidized-bed granulation, which is widely used for wet granulation. To obtain suitable flowability as granules for tabletting, the content of the melting material should be approximately 10 w/w%. The rate of increase in the mean diameter of the granules during FHMG was affected by both the melting temperature and the viscosity of the melting material used in the granules. The compression properties of granules prepared by FHMG were also investigated, demonstrating that these granules had a high pressure transmittance. The hardness and the disintegration time of tablets obtained from granules prepared by FHMG were influenced by the properties of the melting material, such as its compaction behavior, solubility, and wettability. No significant differences of hardness were observed when compared to STF tablets. Tablets prepared from FHMG granules disintegrated within 15 min, whereas the STF tablets showed faster disintegration. It was also demonstrated that the hardness and disintegration time of tablets prepared from FHMG granules were not affected by the tablet porosity. Therefore, tablets with a constant quality may be obtainable under a wide range of compression forces. The results of this study suggested that FHMG is a useful method of preparing granules for tableting without using any solvents or water.

Evaluation of validation of a fully instrumented Hüttlin HKC 05-TJ laboratory-scale fluidized bed granulator

The instrumentation and validation of a laboratory-scale fluidized bed apparatus is described. For continuous control of the process, the apparatus is instrumented with sensors for temperature, relative humidity (RH), and air velocity. Conditions of inlet air, fluidizing air, product, and exhaust air were determined. The temperature sensors were calibrated at temperatures of 0.0 degree C and 99.9 degrees C. The calibration of the humidity sensors covered the range from 12% RH to 98% RH using saturated electrolyte solutions. The calibration of the anemometer took place in a wind tunnel at defined air velocities. The calibrations led to satisfying results concerning sensitivity and precision. To evaluate the reproducibility of the process, 15 granules were prepared under identical conditions. The influence of the type of pump used for delivering the granulating liquid was investigated. Particle size distribution, bulk density, and tapped density were determined. Granules were tableted on a rotary press at four different compression force levels, followed by determination of tablet properties such as weight, crushing strength, and disintegration time. The apparatus was found to produce granules with good reproducibility concerning the granule and tablet properties.

Factors influencing capping and cracking of mefenamic acid tablets

The tendency of capping and longitudinal cracks of mefenamic acid tablets was evaluated in relation to the amount of the binder, the influence of the granulation technique, and the relative humidity of the granules. Tablets made from fluidized bed granules using methylcellulose in the granulating liquid showed significantly lower capping and longitudinal cracks than tablets from conventional granules prepared by wet granulation using methylcellulose as a dry binder.