A PAT Approach to Enhance Process Understanding of Fluid Bed Granulation Using In-line Particle Size Characterization and Multivariate Analysis

The purpose of this study was to achieve improved process understanding of fluid bed granulation using in-line particle size analyzer in conjunction with multivariate methods. The combined use of process analyzers and multivariate tools provides a useful means to drug development within the framework of quality by design utilizing process analytical technology. The evaluation of in-line monitoring manufacturability quality attributes, particle size, and particle size distribution, was conducted using the Parsum probe which is based on spatial filtering technique. Several granulation batches were manufactured and monitored using a commercial-scale fluid bed granulator. Reference measurements by offline Malvern MasterSizer showed good agreement with those by Parsum at end-of-spray phase. Multivariate/batch statistical process control methods were used to evaluate batch process performance, batch-to-batch variation and develop potential control strategy. The results indicated that the Parsum analyzer is a viable tool for in-line particle size characterization and improved process understanding in combination with multivariate tools.     

Investigating the Use of Polymeric Binders in Twin Screw Melt Granulation Process for Improving Compactibility of Drugs

Traditionally, the melt granulation for pharmaceutical products was performed at low temperature (<90°C) with high-shear granulators using low-melting waxy binders, and tablets produced using such granules were not amenable to large-scale manufacturing. The situation has changed in recent years by the use of twin screw extruder where the processing temperature could be increased to as high as 180°C and polymers with high T_g could be used as binders. In this study, different polymeric binders were screened for their suitability in improving compactibility of 2 drugs, metformin hydrochloride and acetaminophen, by twin screw melt granulation. Processing temperatures for the 2 drugs were set at 180°C and 130°C, respectively. Screw configuration, screw speed, and feed rate were optimized such that all polymeric binders used produced granules. Several hydroxypropyl cellulose, hydroxypropyl methylcellulose, polyvinylpyrrolidone, and methacrylate-based polymers, including Klucel^® EXF, Eudragit^® EPO, and Soluplus^®, demonstrated good tablet tensile strength (>2 MPa) when granules were produced using only 10% wt/wt polymer concentration. Certain polymers provided acceptable compactibility even at 5% wt/wt. Thus, twin screw melt granulation process may be used with different polymers at a wide range of temperature. Due to low excipient concentration, this granulation method is especially suitable for high-dose tablets.     

双螺杆制粒技术及其在药物制剂领域中的应用

双螺杆制粒(twin screw granulation,TSG)是制药行业新兴的一种连续湿法制粒技术,目前在国内制药行业报道较少。本文系统介绍了双螺杆挤出制粒机的结构及工作原理,制剂的处方特点及工艺参数对所得颗粒的形状、粒径、孔隙率等性质的影响,并综述了目前国内外TSG的发展现状以及面临的机遇和挑战。虽然TSG技术仍存在一些问题,但是其独特的工艺过程在连续制造生产模式中显示出巨大的优势和潜力。TSG技术的这些优势将会吸引更多研究者的关注,伴随着过程分析技术的发展,将来可能成为制药行业的一个研究热点。     

Hot-Melt Granulation in a Twin Screw Extruder: Effects of Processing on Formulations with Caffeine and Ibuprofen

Hot-melt granulation (HMG) by twin screw extrusion is a novel technology for the continuous processing of pharmaceuticals but confidence must still be gained regarding whether the environment affects drug properties. In this preliminary study, granulation was studied for a model product containing lactose monohydrate and active ingredients of differing water solubility, namely ibuprofen versus caffeine. The formulations were granulated at 220 pm and 100 °C with polyethylene glycol binders of differing molecular weights and at concentrations between 6.5% and 20%. In terms of granule properties, the low melting point of ibuprofen had a dominant influence by producing larger, stronger granules, whereas the caffeine products were more comparable to a blank containing no active ingredient. Drug degradation was studied by differential scanning calorimetry, X-ray diffraction, and high-pressure liquid chromatography. The only detected change was the dehydration of lactose monohydrate for the caffeine and blank products, whereas the lubricating influence of the ibuprofen protected its granules. The short residence time (~ 60 s) was consider to be influential in minimizing damage of the drug despite the high temperature and shear attributed to HMG inside a twin screw extruder.     

Continuous Twin Screw Wet Granulation and Drying—Control Strategy for Drug Product Manufacturing

The use of continuous manufacturing has been increasing within the pharmaceutical industry over the last few years. Continuous direct compression has been the focus of publications on the topic to date. The use of wet granulation can improve segregation resistance, uniformity, enhance density, and flow properties for improved tabletability, or improve stability of products that cannot be manufactured by using a direction compression process. This article focuses on development of appropriate control strategies for continuous wet granulation (especially twin screw wet granulation) through equipment design, material properties and manufacturing process along with areas where additional understanding is required. The article also discusses the use of process analytical technologies as part of the control and automation approach to ensure a higher assurance of product quality. Increased understanding of continuous wet granulation should result in increased utilization of the technique, thereby allowing for an increase in diversity of products manufactured by continuous manufacturing and the benefits that comes with a more complex process such as wet granulation compared with direct compression process.     

Design and In-line Raman Spectroscopic Monitoring of a Protein Batch Crystallization Process

Raman spectroscopy was used to design and monitor a lysozyme protein batch crystallization process in a lab scale study to facilitate the design of a pharmaceutical protein manufacturing process. A D-optimal design that consisted of 18 experiments was performed to elucidate the effect of temperature, concentration of the precipitating agent, time of crystallization, and possible interactions between these three factors on the Raman scattering changes. A polynomial mathematical model was calculated relating the scattering of the lysozyme solutions measured at individual Raman shifts to the significant factors obtained in the previous crystallization experiment. The 2,940-cm⁻¹ band provided the highest correlation values indicative of small prediction errors and good predictive ability for the crystallization model. Raman scattering signals obtained during the experiments were used as input to obtain a response surface for the factors studied and elucidate the relationship between the crystallization process conditions and the crystals obtained. The main factors affecting the crystallization process were the sodium chloride concentration and temperature.     

Application of In-line Focused Beam Reflectance Measurement to Brivanib Alaninate Wet Granulation Process to Enable Scale-up and Attribute-based Monitoring and Control Strategies

Application of in-line real-time process monitoring using a process analytical technology for granule size distribution can enable quality-by-design development of a drug product and enable attribute-based monitoring and control strategies. In this study, an in-line laser focused beam reflectance measurement (FBRM) C35 probe was used to investigate the effect of formulation and process parameters on the granule growth profile over time during the high shear wet granulation of a high drug load formulation of brivanib alaninate. The probe quantitatively captured changes in the granule chord length distribution (CLD) with the progress of granulation and delineated the impact of water concentration used during granulation. The results correlated well with offline particle size distribution measured by nested sieve analyses. An end point indication algorithm was developed that was able to successfully track the process time needed to reach the target CLD. Testing of the brivanib alaninate granulation through 25-fold scale-up of the batch process indicated that the FBRM CLD profile can provide a scale-independent granule attribute-based process fingerprint. These studies highlight the ability of FBRM to quantitate a granule attribute of interest during wet granulation that can be used as an attribute-based scale-up and process monitoring and control parameter.     

Scaleup of a High-Shear Granulation Process Using a Normalized Impeller Work Parameter

A method was evaluated to accurately identify the granulation end points of microcrystalline cellulose formulations by monitoring impeller work during high-shear processing. Impeller watt meters were calibrated in situ to a common standard to enable direct comparison of power values between equipment. Integration of the impeller power (watts) versus time (seconds) profile provides an energy parameter (watt seconds) or “work of granulation” for correlation with physical changes in tablet properties and performance. Granulation end points were accurately predicted for 25-, 65-, and 150-liter manufacturing scales on the basis of development work run on 5.0- and 10-liter equipment using work values normalized for the weight of dry powders in the granulator (watt sec/g). The ability to arrive at functionally equivalent granulation end points, in different equipment and at different impeller speeds, was established through comparison of cohesion indexes (slopes of the tablet breaking strength versus compression force profiles) and granulation size distributions determined by sieve analysis. Work measured at the impeller correlated quantitatively with changes in the granulation bulk and tapped densities, average particle size of the finished powders, and cohesion index, independent of granulator make or model. The observed changes in granulation properties, however, did not correlate with individual process variables such as impeller power (watts) or process time.     

Effects of Process and Design Parameters on Granule Size Distribution in a Continuous High Shear Granulation Process

Purpose

Wet granulation is widely used in the pharmaceutical industry. This advantageous technology is capable of enhancing compression and powder handling, decreasing ingredient segregation, and promoting blend and content uniformity. Currently, a high level of interest exists in the continuous version of this technology, both by the US Food and Drug Administration (FDA), and by pharmaceutical manufacturers.

Methods

In this paper, a continuous high shear wet granulation process was examined based on a placebo formulation comprising 70% ?-lactose monohydrate and 30% microcrystalline cellulose (Avicel® PH101). Granulation was then carried out in a continuous high shear mixer granulator, Glatt GCG 70. The impact of two process variables (rotation speed and liquid/solid (L/S) ratio) and two design parameters (blade configuration and nozzle position) were evaluated via an I-optimal design.

Results

Multi-factor analysis of variance (ANOVA) indicated that rotation speed and L/S ratio dominated the granulation process and had the most significant effects on granule size distribution (GSD). The largest granule mass median diameter was obtained at the lowest rotation speed and highest L/S ratio. The granulation mechanism underlying this continuous process was examined using a wetting and nucleation regime map. For the cases studied here, the mechanical dispersion regime controlled the formation of granule nuclei, leading to a broad GSD and a limited growth ratio.

     

糖肾颗粒流化床制粒过程监测与控制

目的 解决糖肾颗粒流化床制粒过程中“塌床”问题。方法 通过对糖肾颗粒制粒过程中进风温度、物料温度、供液速度、风机频率、颗粒粒径分布、水份含量、流动性的监测,分析颗粒塌床的原因,找出塌床时的颗粒特征。结果 当颗粒水份含量大于3%和粒径分布Dx(90)大于400μm时,容易出现塌床。结论 通过对颗粒质量的监测和控制,可以有效预判流化床制粒中遇到的工艺问题。     

How Deformation Behavior Controls Product Performance After Twin Screw Granulation With High Drug Loads and Crospovidone as Disintegrant

This study addresses the quantitative influence of 12 different materials (active pharmaceutical ingredients and excipients as surrogate active pharmaceutical ingredients) on the critical quality attributes of twin screw granulated products and subsequently produced tablets. Prestudies demonstrated the significant influence of the chosen model materials (in combination with crospovidone) on the disintegration behavior of the resulting tablets, despite comparable tablet porosities. This study elucidates possible reasons for the varying disintegration behavior by investigating raw material, granule, and tablet properties. An answer could be found in the mechanical properties of the raw materials and the produced granules. Through compressibility studies, the materials could be classified into materials with high compressibility, which deform rather plastically under compression stress, and low compressibility, which display breakages under compression stress. In general, and apart from (pseudo)-polymorphic transformations, brittle materials featured excellent disintegration performance, even at low resulting tablet porosities <8%, whereas plastically deformable materials mostly did not reveal any disintegration. These findings must be considered in the development of simplified formulations with high drug loads, in which the active pharmaceutical ingredient predominantly defines the deformation behavior of the granule.     

In situ Monitoring of Wet Granulation Using Online X-Ray Powder Diffraction

PURPOSE: Polymorphic transformations during the wet granulation of a metastable polymorph of flufenamic acid were monitored in situ using online X-ray powder diffraction. The resulting data were used in testing a proposed process induced transformation rate model, which allows the extent and occurrence of polymorphic transformations during wet granulation to be controlled by adjusting the granulation time. METHODS: A small-scale, top mixing granulator was designed for compatibility with novel X-ray powder diffraction equipment (available from X-Ray Optical Systems of East Greenbush, NY). RESULTS: The unique polycapillary optic and X-ray source allowed the transformation of the metastable to the stable polymorph to be followed during the granulation. Following a diffraction peak each for the metastable and stable forms demonstrated that polymorphic transformations during the wetting phase of granulation follow the trends predicted by the model. CONCLUSIONS: The advanced online monitoring may allow real-time control of the process by the adjustment of process parameters, such as granulation time, and clearly qualifies as a PAT (process analytical technology).     

End-Point Detection in a Wet Granulation Process

The purpose of the experiments in this paper was to evaluate granulation end-point control by power consumption measurement in a 25-L high shear mixer. The effect of impeller design, impeller speed, liquid addition rate, type of binder, and mixing ratio between lactose and starch on the correlation between power consumption and granule growth was investigated in the liquid addition phase of the process using a fractional factorial experimental design. There was found generally a linear correlation between power consumption and mean granule size, but this correlation was dependent on the impeller design, the impeller speed, and the type of binder. However, an end-point control based on power consumption was not found to be sensitive to variations in the lactose:starch ratio. It was concluded that it was possible to control the liquid addition by the level detection method by which the liquid addition is stopped at a predetermined level of power consumption. An end-point control based upon the peak detection method was not generally applicable, because a peak in the differentiated power consumption signal could not be identified in all the experiments.     

Optimization of the High-Shear Wet Granulation Wetting Process Using Fuzzy Logic Modeling

A fuzzy model has been developed for the optimization of high-shear wet granulation wetting on a plant scale depending on the characteristics of pharmaceutical active substance particles. The model optimized on the basis of experimental data involves a set of rules obtained from expert knowledge and full-scale process data. The skewness coefficient of particle size distribution and the tapped density of the granulated mixture were chosen as the model input variables. The output of the fuzzy ruled system is the optimal quantity of wetting liquid. In comparison to manufacturing practice, a very strong sensitivity of the optimal quantity of the added wetting liquid to the size and shape of the active substance particles has been identified by fuzzy modeling.     

Agglomeration of Mesoporous Silica by Melt and Steam Granulation. Part II: Screening of Steam Granulation Process Variables Using a Factorial Design

The objectives of this study were to identify the key process parameters during steam granulation of disordered mesoporous silica material Syloid® 244 FP (244) and to compare two different binders: polyvinylpyrrolidone (PVP) K25 and hydroxypropylmethyl cellulose (HPMC). Itraconazole (ITZ) was selected as the model compound for the development of an oral dosage form for enhanced release. Six factors: binder content, steam amount, mixing time, impeller speed, spray pause time, and filler content were investigated using a two-level quarter-fraction factorial design of experiment (DOE) for each binder type. As experimental responses, characteristics correlating to both granules and tablets were selected. Granules prepared from PVP resulted in an overall higher bulk density, granule size, increased flow properties, and better compression and compaction behavior. Although granulation with PVP resulted in the most ITZ to extract from the pores during processing, the premature drug release was less than 5%. The results of the DOE indicate that the risk of extracting the drug from the pores during processing is governed both by the process parameters and the binder properties. Centerpoint replicates of granules prepared with HPMC were highly variable. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:3978–3986, 2013     

De-risking Scale-up of a High Shear Wet Granulation Process Using Latent Variable Modeling and Near-Infrared Spectroscopy

In the development of wet granulated drug products, two primary sources of variance (disturbance) include the operational scale of the high shear wet granulation (HSWG) process and active pharmaceutical ingredient (API) lot-to-lot variability, particularly for formulations containing a high drug load. This paper presents a novel Process Analytical Technology strategy using latent variable modeling with near-infrared spectroscopy (NIRS) to reduce risk in scale-up operations of the HSWG process while simultaneously accounting for API lot-to-lot variability, even with limited manufacturing history. The process involves building a partial least square (PLS) model among the API material properties, the HSWG process parameters, and the NIRS end points of the HSWG process based on small-scale design of experiment batches. The PLS model is then used in an optimization framework to find suitable small-scale mechanical process parameters (impeller/chopper speed) that approximate a previous large-scale operation so as to keep the NIRS end point of large-scale operation constant. Prior to making additional large-scale batches with a new lot of API, NIRS end points of large-scale HSWG with the new API lot are predicted based on the PLS model developed from the small-scale operation. If the predicted NIRS end point for the HSWG using the new API lot is not within the target region, the risks associated with the scale-up operation can then be significantly reduced by modifying other HSWG process parameters such as the total amount of water added or total granulation time to achieve the target region. A case study is presented that demonstrates the effectiveness of this methodology during development and scale-up of a drug product manufactured using a HSWG process.     

Risk Assessment for a Twin-Screw Granulation Process Using a Supervised Physics-Constrained Auto-encoder and Support Vector Machine Framework

Pharmaceutical Research - Quality risk management is an important task when it pertains to the pharmaceutical industry, as this is directly related to product performance. With the ICH Q9...     

The Relation Between Granule Size,Granule Stickiness,and Torque in the High-Shear Granulation Process

No HeadingPurpose. To investigate the background of the observed relationship between measured torque and granule size in high-shear granulation processes.Methods. Torque was measured during the granulation process; the behavior of individual wet granules during compaction was investigated using micromanipulation. Surface properties of wet granules were manipulated by coating them with talc.Results. The torque-granule size relationship could not be explained by the rise in mass of the individual granules; it occurs rather through an increase in stickiness of the granules when the moisture content is increased. Obviously, the increased stickiness that causes the granules to grow also increases the torque. Increased stickiness was shown to be the result of an increased deformability of the granules at higher moisture contents, in combination with a change in surface properties. The elastic-plastic behavior (ratio of elastic to plastic deformation) was found to change at increasing moisture contents.Conclusions. Our results imply that changes in the stickiness of the granular material that may be caused by changes in composition shift the torque-size relationship. This may be of particular importance when, for example, granulation results from placebo batches are used to predict the granule size of drug-containing batches.     

Developing a Virtual Flowability Sensor for Monitoring a Pharmaceutical Dry Granulation Line

Current technologies to measure granule flowability involve at-line methods that can take hours to perform. This is problematic for a continuous dry granulation tableting line, where the quality assurance and control of the final tablet products depend on real-time monitoring and control of powder flowability. Hence, a real-time alternative is needed for measuring the flowability of the granular products coming out of the roller compactor, which is the unit operation immediately preceding the tablet press. Since particle analyzers have the potential to take inline measurements of the size and shape of granules, they can potentially serve as real-time flowability sensors, given that the size and shape measurements can be used to reliably predict flowability measurements.This paper reports on the use of Partial Least Squares (PLS) regression to utilize distributions of size and shape measurements in predicting the output of three different types of flowability measurements: rotary drum flow, orifice flow, and tapped density analysis. The prediction performance of PLS had a coefficient of determination ranging from 0.80 to 0.97, which is the best reported performance in the literature. This is attributed to the ability of PLS to handle high collinearity in the datasets and the inclusion of multiple shape characteristics—eccentricity, form factor, and elliptical form factor—into the model. The latter calls for a change in industry perspective, which normally dismisses the importance of shape in favor of size; and the former suggests the use of PLS as a better way to reduce the dimensionality of distribution datasets, instead of the widely used practice of pre-selecting distribution percentiles.     

Modeling the Process of Fluidized-Bed Granulation of a Dry Ginseng Extract

Pharmaceutical Chemistry Journal -