Exploratory studies in heat-assisted continuous twin-screw dry granulation: A novel alternative technique to conventional dry granulation

Chrono modulated multiple unit particulate systems (MUPS) via a continuous hot melt double extrusion technique: Investigation of the formulation and process suitability

The current study is aimed at the development of chrono modulated multiple unit particulate systems (MUPS) of nifedipine (ND) by a continuous double extrusion process. ND, a poorly soluble drug was formulated into an amorphous solid dispersion (ASD) to improve its solubility. Further, the ASD was converted into MUPS to control the drug release through a combination of pulsatile and sustained release portions. In the preparation of the ASD, the polymer HPMCAS LG was employed at different concentrations. MUPS were formulated by using Eudragit® FS100, Eudragit® RSPO, Klucel™ HF and lipids Precirol® ATO 5, Geleol™, Compritol® ATO5. The differential scanning calorimetry and powder X-ray diffraction studies of MUPS revealed the amorphous nature of ND. Scanning electron microscopy (SEM) studies depicted the surface morphology of the ASD and the gradual change in the surface of the coated MUPS during in-vitro release studies. The in-vitro drug release profiles of ASD indicated significant improvement (p < 0.05) of solubility of ND and MUPS demonstrated a combination of pulsatile and zero-order controlled release up to 12 h. Accelerated stability studies for MUPS at 40 °C/75% RH revealed the formulations were stable. These findings suggest hot melt double extrusion as a potential alternative for conventional techniques to produce MUPS.

The Effect of Process Variables and Binder Concentration on Tabletability of Metformin Hydrochloride and Acetaminophen Granules Produced by Twin Screw Melt Granulation with Different Polymeric Binders

In twin screw melt granulation, granules are produced by passing mixtures of drug substances and polymeric binders through twin screw extruder such that temperatures are maintained below melting point of drugs but above glass transition of polymers used, whereby the polymers coat surfaces of drug particles and cause their agglomeration into granules. Since various formulation factors, such as binder type and concentration, and processing variables like extrusion temperature, screw configuration, and screw speed, can influence the granulation process, the present investigation was undertaken to study their effects on tabletability of granules produced. Three different types of polymeric binders, Klucel® EXF (hydroxypropyl cellulose), Eudragit® EPO (polyacrylate binder), and Soluplus® (polyvinyl caprolactam-co-vinyl acetate-ethylene glycol graft polymer), were used at 2, 5, and 10% concentrations. Metformin hydrochloride (HCl) (mp: 222°C) and acetaminophen (mp: 169°C) were used as model drugs, and drug-polymer mixtures with metformin HCl were extruded at 180, 160, and 130°C, while those with acetaminophen were extruded at 130 and 110°C. Other process variables included screw configurations: low, medium, and high shear for metformin HCl, and low and medium shear for acetaminophen; feed rates: 20 and 60 g/min; and screw speed of 100 and 300 RPM. Formulation and process variables had significant impact on tabletability. The target tensile strength of ≥2 MPa could be obtained with all polymers and at all processing temperatures when metformin HCl was granulated at 180°C and acetaminophen at 130°C. At other temperatures, the target tensile strength could be achieved at certain specific sets of processing conditions.

Twin-Screw Melt Granulation for Oral Solid Pharmaceutical Products

This article highlights the advantages of pharmaceutical continuous melt granulation by twin-screw extrusion. The different melt granulation process options and excipients are described and compared, and a case is made for expanded use of twin-screw melt granulation since it is a flexible and continuous process. Methods for binder selection are profiled with a focus on rheology and physical stability impacts. For twin-screw melt granulation, the mechanism of granulation and process impact on granule properties are described. Pharmaceutical applications of melt granulation ranging from immediate release of soluble and insoluble APIs, taste-masking, and sustained release formulation are reviewed, demonstrating the range of possibilities afforded by twin-screw melt granulation.

Advances in Twin-Screw Granulation Processing

Twin-screw granulation (TSG) is a pharmaceutical process that has gained increased interest from the pharmaceutical industry for its potential for the development of oral dosage forms. The technology has evolved rapidly due to the flexibility of the equipment design, the selection of the process variables and the wide range of processed materials. Most importantly, TSG offers the benefits of both batch and continuous manufacturing for pharmaceutical products, accompanied by excellent process control, high product quality which can be achieved through the implementation of Quality by Design (QbD) approaches and the integration of Process Analytical Tools (PAT). Here, we present basic concepts of the various twin-screw granulation techniques and present in detail their advantages and disadvantages. In addition, we discuss the detail of the instrumentation used for TSG and how the critical processing paraments (CPP) affect the critical quality attributes (CQA) of the produced granules. Finally, we present recent advances in TSG continuous manufacturing including the paradigms of modelling of continuous granulation process, QbD approaches coupled with PAT monitoring for granule optimization and process understanding.

A One-Step Twin-Screw Melt Granulation with Gelucire 48/16 and Surface Adsorbent to Improve the Solubility of Poorly Soluble Drugs: Effect of Formulation Variables on Dissolution and Stability

Fenofibrate is an effective lipid-lowering drug; however, its poor solubility and high log p (5.2) result in insufficient absorption from the gastrointestinal tract, leading to poor bioavailability. In this study, a one-step continuous twin-screw melt granulation process was investigated to improve the solubility and dissolution of fenofibrate using Gelucire® 48/16 and Neusilin® US2 as the solubilizer and surface adsorbent, respectively. The formulations (granules) were prepared at different ratios of fenofibrate, Gelucire® 48/16, and Neusilin® US2 based on phase-solubility studies and characterized using dissolution, differential scanning calorimetry, powder X-ray diffraction, and scanning electron microscopy analyses and studies on flow properties. In the phase-solubility studies, a linear relation was observed between Gelucire® 48/16 concentration and the amount of fenofibrate dissolved. In contrast, the dissolution rate of the prepared formulations was independent of the fenofibrate: Gelucire® 48/16 ratio and dependent on the Neusilin® US2 levels in the formulation. Increasing Neusilin® US2 levels decreased the rate of dissolution of the granules but improved the stability of the tablets under storage at accelerated stability conditions. Interestingly, higher Gelucire® 48/16 levels in the granules resulted in tablets with a hard matrix, which slowed disintegration and dissolution. All formulations exhibited improved dissolution compared to pure fenofibrate.

Process optimization of twin-screw melt granulation of fenofibrate using design of experiment (DoE)

The purpose of this study was to optimize the melt granulation process of fenofibrate using twin-screw granulator. Initial screening was performed to select the excipients required for melt granulation process. A 3 × 3 factorial design was used to optimize the processing conditions using the % drug loading (X₁) and screw speed (X₂) as the independent parameters and granule friability (Y₁) % yield (Y₂) as the dependent parameters. The effect of the independent parameters on the dependent parameters was determined using response surface plots and contour plots. A linear relationship was observed between % drug loading (X₁) and % friability (Y₁) and a quadratic relationship was observed between the independent parameters (X₁ and X₂) and % yield (Y₂). The processing conditions for optimum granules were determined using numerical and graphical optimization and it was found that 15% drug loading at 50 rpm results in maximum % yield of 82.38% and minimum friability of 7.88%. The solid-state characterization of the optimized granules showed that the drug turned from crystalline state to amorphous state during melt granulation process. The optimized granules were compressed into tablets using Purolite® as the super disintegrating agent. The optimized formulation showed >85% drug release in 0.75% SLS solution within 60 min.

Theophylline-nicotinamide pharmaceutical co-crystals generated using hot melt extrusion technology: Impact of polymeric carriers on processability

The objective of the current study was to develop theophylline (TPH) nicotinamide (NAM) pharmaceutical co-crystals using the hot melt extrusion (HME) technology and evaluate the processability of the co-crystals using different polymeric carriers. A physical mixture of 1:1 M ratio of TPH and NAM was employed to prepare the co-crystals. Hydroxypropylmethylcellulose acetate succinate, polyethylene oxide, and Kollidon® VA-64 (5% w/w) were investigated as polymeric carriers for the HME process. Solid-state characterization using differential scanning calorimetry showed two endothermal peaks, one at 126.4 °C indicating eutectic formation and another at 174 °C indicating the melting point of the co-crystal for all formulations, except the Kollidon® VA-64 extrudates, which showed a single peak at 174 °C. Fourier-transform infrared spectroscopy and powder X-ray diffraction studies revealed the formation of co-crystals. The feasibility to formulate the extrudates into solid dosage forms was assessed by formulating a tablet blend. The three-month stability studies showed no degradation at the accelerated stability conditions of 40 (±2) ° C and 75 (±5) % RH. Finally, the results demonstrated that the presence of mixing zones in screw configuration and extrusion temperature are critical processing parameters that influence co-crystal formation.

Hypromellose acetate succinate based amorphous solid dispersions via hot melt extrusion: Effect of drug physicochemical properties

In this study, the impact of drug and hydroxypropyl methylcellulose acetate succinate (HPMCAS) grades physicochemical properties on extrusion process, dissolution and stability of the hot melt extruded amorphous solid dispersions (ASDs) of nifedipine and efavirenz was investigated. Incorporation of drugs affected the extrusion temperature required for solid dispersion preparation. Differential scanning calorimetry and powder X-ray diffraction studies confirmed the amorphous conversion of the drugs in the prepared formulations. The amorphous nature of ASDs was unchanged after 3 months of stability testing at 40 °C and 75% relative humidity. The dissolution efficiency of the ASDs was dependent on the log P of the drug. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and dose of the drug. The dissolution efficiency and dissolution rate of the ASDs were dependent on the log P of the drug and solubility and hydrophilicity of the polymer grade respectively. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and the dissolution dose of the drug.

Continuous twin screw granulation - An advanced alternative granulation technology for use in the pharmaceutical industry

Hot melt extrusion has been an exciting technology in the pharmaceutical field owing to its novel applicability. Twin-screw granulation presents a great potential and offers many advantages relative to conventional granulation processes. Different twin-screw granulation techniques, such as twin-screw dry granulation, twin-screw wet granulation, and twin-screw melt granulation, are currently being developed as robust and reproducible granulation processes. The competence of twin-screw granulation as a continuous manufacturing process has contributed to its suitability as an alternative granulation option within the pharmaceutical industry. In this article, different types of twin-screw granulation techniques were discussed. In addition, the screw elements, scale-up process, continuous twin-screw granulation which involves process analytical tools, and excipients were explored. This economical, industrially scalable process can be automated for continuous manufacturing to produce granules for the development of oral solid dosage forms. However, extensive research using process analytical tools is warranted to develop processes for the continuous manufacture of granules.

Recent progress in continuous manufacturing of oral solid dosage forms

Continuous drug product manufacturing is slowly being implemented in the pharmaceutical industry. Although the benefits related to the quality and cost of continuous manufacturing are widely recognized, several challenges hampered the widespread introduction of continuous manufacturing of drug products. Current review presents an overview of state-of-the art research, equipment, process analytical technology implementations and advanced control strategies. Additionally, guidelines and regulatory viewpoints on implementation of continuous manufacturing in the pharmaceutical industry are discussed.

An update on the contribution of hot-melt extrusion technology to novel drug delivery in the twenty-first century: part II

INTRODUCTION

Interest in hot-melt extrusion (HME) technology for novel applications is growing day by day, which is evident from several hundred publications within the last 5 years. HME is a cost-effective, solvent free, 'green' technology utilized for various formulations with low investment costs compared to conventional technologies. HME has also earned the attention of the pharmaceutical industry by the transformation of this technology for application in continuous manufacturing.

AREAS COVERED

Part II of the review focuses on various novel opportunities or innovations of HME such as multiple component systems (co-crystals, co-amorphous systems and salts), twin-screw granulation, semi-solids, co-extrusion, abuse deterrent formulations, solid self-emulsifying drug delivery systems, chronotherapeutic drug delivery systems, and miscellaneous applications.

EXPERT OPINION

HME is being investigated as an alternative technology for preparation of multicomponent systems such as co-crystals and co-amorphous techniques. Twin-screw granulation has gained increased interest in preparation of granules via twin-screw melt granulation or twin-screw dry granulation. This novel application of the HME process provides a promising alternate approach in the formulation of granules and solid dosage forms. However, this technology may need to be further investigated for scalability aspects of these novel applications for industrial production.

Effects of Processing on a Sustained Release Formulation Prepared by Twin-Screw Dry Granulation

Dry granulation is an indispensable process used to improve the flow property of moisture-sensitive materials. Considering the limitations of currently available dry granulation techniques, it is necessary to develop a novel technique. In this study, a twin-screw dry granulation (TSDG) technology was successfully applied to produce a sustained-release dry granule formulation, which was subsequently compressed into sustained-release tablets. Based on a preliminary study, theophylline was selected as model drug, Klucel^™ EF, Ethocel^™, and magnesium stearate were selected as excipients. A Resolution V Irregular Fraction Design was applied to determine the effect of different processing parameters (screw speed, feeding rate, barrel temperature, and screw configuration) on product properties (flow properties, particle size distribution, and dissolution time). A reliable model was achieved by combining the data obtained, and processing parameters were automatically optimized to attain the setting goal. In general, TSDG was demonstrated to be an alternative method for the preparation of dry granules. The continuous processing nature, simplicity of operation, and ease of optimization made TSDG competitive compared with other conventional dry granulation techniques.