Fabrication of a Shell-Core Fixed-Dose Combination Tablet Using Fused Deposition Modeling 3D Printing

Exploration of Conventional and FDM-Mediated 3D Printed Tablets Fabricated Using HME-Based Filaments for pH-Dependent Drug Delivery

Hot melt extrusion (HME) helps to improve the solubility of BCS class II and IV molecules. The downstream processing of the resulting filaments was crucial in developing the final dosage form. The present work investigates advantages of combining HME with fused deposition modelling (FDM) 3-Dimensional (3D) printing in delivering the naringenin to the colon to treat inflammatory bowel disease. HME filaments were made using a pH-sensitive polymer hydroxypropyl methylcellulose acetate succinate for the localized delivery of naringenin at the colonic pH. Polyethylene glycol (PEG - 4000) and Aerosil 200 were incorporated as plasticizer and flow modulator respectively, to facilitate the extrusion process. Naringenin was converted to amorphous form as confirmed by differential scanning calorimetry and powder x-ray diffraction. The optimized filament showed 0.03, 11.52 and 77.80% drug release at pH 1.2, 6.8 and 7.4 respectively. The tablets produced with the optimized filament by compression and 3D printing also confirmed the presence of naringenin in amorphous form and demonstrated pH-dependent release followed by zero-order release independent of the concentration. The dissolution profiles of FDM 3D printed (3DP) tablets with varying dimensions and infill densities suggested that both significantly influenced drug release from the tablets without altering the composition of tablets, indicating the potential application of 3D printing technology in developing personalized medicine according to patient requirements. These promising results may be valuable in evaluating the potential of naringenin in animal models, which may further facilitate clinical applications.

Selective laser sintering for printing bilayer tablets

In this study Selective Laser Sintering (SLS) was used to produce bilayer tablets containing rosuvastatin and acetylsalicylic acid. Initially, monolithic tablets of each drug were manufactured using different laser intensities in order to identify their impact on the tablet's dissolution, friability and hardness. After the optimization, the final bilayer tablet was fabricated using a new method, that allowed the printing using different powder blends. For that, a 3D-printed casing was employed to maintain the compartments of the tablet in the correct position during the printing process. The results demonstrated that the increased laser intensities led to denser inner cores, enhanced hardness, decreased friability, and slower drug release. Moreover, the new method was able to produce bilayer tablets completely aligned, showing a minor impact on dissolution when the two compartments were printed together in a single tablet. The work demonstrated the feasibility of using SLS in the production of multi-material drug delivery systems.

3D printing of pharmaceutical dosage forms: Recent advances and applications

Three-dimensional (3D) printing, also referred to as additive manufacturing, is considered to be a game-changing technology in many industries and is also considered to have potential use cases in pharmaceutical manufacturing, especially if individualization is desired. In this review article the authors systematically researched literature published during the last 5 years (2019 - spring 2024) on the topic of 3D printed dosage forms. Besides all kinds of oral dosage forms ranging from tablets and capsules to films, pellets, etc., numerous reports were also identified on parenteral and cutaneous dosage forms and also rectal, vaginal, dental, intravesical, and ophthalmic preparations. In total, more than 500 publications were identified and grouped according to the site of administration, and an overview of the manuscripts is presented here. Furthermore, selected publications are described and discussed in more detail. The review highlights the very different approaches that are currently used in order to develop 3D printed dosage forms but also addresses remaining challenges.

Fabrication of osmotic pump tablets utilizing semisolid extrusion three-dimensional printing technology

The utilization of three-dimensional (3D) printing technology is prevalent in the fabrication of oral sustained release preparations; however, there is a lack of research on 3D-printed osmotic pump tablets. A 3D-printed core-shell structure bezafibrate osmotic pump tablet was developed based on the characteristics of rapid absorption and short half-life of bezafibrate, utilizing semisolid extrusion (SSE) 3D printing technology. First, the properties of different shell materials were investigated to define the composition of the shell, and ultimately, the optimal formulation was found to be ethyl cellulose:cellulose acetate:polyethylene glycol = 2:1:2. The formulation of the tablet core was defined based on the printing performance and release behavior. The formulation consisted of bezafibrate, lactis anhydrous, sodium bicarbonate, sodium alginate, polyethylene oxide and sodium dodecyl sulfate at a ratio of 400:400:300:80:50:50. The tablet was capable of achieving zero-order release. The physicochemical properties were also characterized. The pharmacokinetic data analysis indicated that there were no statistically significant differences in the pharmacokinetic parameters between the 3D-printed tablets and the reference listed drugs. There was a strong correlation between the in vitro and in vivo results for the 3D-printed tablets. The results showed that SSE printing is a practical approach for manufacturing osmotic pump tablets.

Advances in Loading Techniques and Quality by Design for Fused Deposition Modeling in Pharmaceutical Production: A Systematic Review

BACKGROUND/OBJECTIVES

Three-dimensional printing technology has emerging interest in pharmaceutical manufacturing, offering new opportunities for personalized medicine and customized drug delivery systems. Fused deposition modeling (FDM) is highly regarded in the pharmaceutical industry because of its cost effectiveness, easy operation, and versatility in creating pharmaceutical dosage forms. This review investigates different methods of incorporating active pharmaceutical ingredients (APIs) into filament matrices for use in fused deposition modeling (FDM) 3D printing.

METHODS

Two electronic databases, the Web of Science and PubMed, were utilized to survey the literature. The selected keywords for this review were as follows: fused filament fabrication OR fused deposition modeling OR FDM OR FFF AND 3D printing AND loading techniques OR impregnation techniques AND solid dosage form.

RESULTS

This paper evaluates various loading techniques such as soaking, supercritical impregnation, microwave impregnation, and hot-melt extrusion, focusing on their effectiveness and capacity for drug incorporation. Additionally, this review includes a thorough risk assessment of the extrusion process using Ishikawa and SWOT analyses.

CONCLUSIONS

Overall, this review provides comprehensive insights into the latest advancements in 3D printing for pharmaceutical applications and identifies key areas for future research and development.

3D printed tinidazole tablets coupled with melt-extrusion techniques for formulating child friendly medicines

This study investigates the feasibility of fabrication of poly(1-vinyl-2-pyrrolidone) (Kollidon®25)-mediated filaments for producing tinidazole (TNZ)-loaded, customizable, child-friendly tablets (with varying shapes and sizes) using hot melt extrusion (HME) coupled with fused deposition modeling (FDM) technology. Kollidon®25, chosen for its ability to enhance the dissolution of TNZ (a BCS Class II drug), was evaluated for polymer-drug compatibility through Hansen solubility, polarity, and interaction parameter analyses, confirming good miscibility and affinity between TNZ and Kollidon®25. Placebo- and TNZ-loaded filaments were prepared in different ratios using HME, followed by the development of 3D-printed tablets via FDM. The fabricated batches of placebo and TNZ-loaded 3D tablets were characterized, and it was found that they had an average weight variation of 270.41 ± 7.44 mg and 270.87 ± 9.33 mg, hardness of 155.01 ± 11.79 N and 265.3 ± 7.62 N, and friability of 0.1583 ± 0.0011 % and 0.2254 ± 0.0013 %. Amorphization was confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) analysis. Scanning electron microscopy (SEM) revealed a layer-by-layer pattern with tiny fractures on the tablet surfaces, which enhanced media penetration, resulting in improved dissolution profiles. The TNZ release profile showed complete 100 % release within 2.0 h in a gastric acidic medium. These findings support the potential of Kollidon®25 to create customizable, child-friendly, 3D-printed dosage forms with different shapes and sizes for TNZ delivery, offering a unique approach to paediatric medications.

Application of 3D printing on the design and development of pharmaceutical oral dosage forms

3D printing technologies confer an unparalleled degree of control over the material distribution on the structures they produce, which has led them to become an extremely attractive research topic in pharmaceutical dosage form development, especially for the design of personalized treatments. With fine tuning in material selection and careful design, these technologies allow to tailor not only the amount of drug administered but the biopharmaceutical behaviour of the dosage forms as well. While fused deposition modelling (FDM) is still the most studied 3D printing technology in this area, others are gaining more relevance, which has led to many new and exciting dosage forms developed during 2022 and 2023. Considering that these technologies, in time, will join the current manufacturing methods and with the ever-increasing knowledge on this topic, our review aims to explore the advantages and limitations of 3D printing technologies employed in the design and development of pharmaceutical oral dosage forms, giving special focus to the most important aspects governing the resulting drug release profiles.

Evaluation of Printability of PVA-Based Tablets from Powder and Assessment of Critical Rheological Parameters

Fused deposition modeling (FDM) is a rather new technology in the production of personalized dosage forms. The melting and printing of polymer-active pharmaceutical ingredient (API)-mixtures can be used to produce oral dosage forms with different dosage as well as release behavior. This process is utilized to increase the bioavailability of pharmaceutically relevant active ingredients that are poorly soluble in physiological medium by transforming them into solid amorphous dispersions (ASD). The release from such ASDs is expected to be faster and higher compared to the raw materials and thus enhance bioavailability. Printing directly from powder while forming ASDs from loperamide in Polyvinylalcohol was realized. Different techniques such as a change in infill and the incorporation of sorbitol as a plastisizer to change release patterns as well as a non-destructive way for the determination of API distribution were shown. By measuring the melt viscosities of the mixtures printed, a rheological model for the printer used is proposed.

3D printed microfluidic devices for integrated solid-phase extraction and microchip electrophoresis of preterm birth biomarkers

BACKGROUND

Preterm birth (PTB) is a leading cause of neonatal mortality, such that the need for a rapid and accurate assessment for PTB risk is critical. Here, we developed a 3D printed microfluidic system that integrated solid-phase extraction (SPE) and microchip electrophoresis (μCE) of PTB biomarkers, enabling the combination of biomarker enrichment and labeling with μCE separation and fluorescence detection.

RESULTS

Reversed-phase SPE monoliths were photopolymerized in 3D printed devices. Microvalves in the device directed sample between the SPE monolith and the injection cross-channel in the serpentine μCE channel. Successful on-chip preconcentration, labeling and μCE separation of four PTB-related polypeptides were demonstrated in these integrated microfluidic devices. We further show the ability of these devices to handle complex sample matrices through the successful analysis of labeled PTB biomarkers spiked into maternal blood serum. The detection limit was 7 nM for the PTB biomarker, corticotropin releasing factor, in 3D printed SPE-μCE integrated devices.

SIGNIFICANCE

This work represents the first successful demonstration of integration of SPE and μCE separation of disease-linked biomarkers in 3D printed microfluidic devices. These studies open up promising possibilities for rapid bioanalysis of medically relevant analytes.

Tailoring drug release in bilayer tablets through droplet deposition modeling and injection molding

This study explores the innovative production of personalized bilayer tablets, integrating two advanced manufacturing techniques: Droplet Deposition Modeling (DDM) and Injection Molding (IM). Unlike traditional methods limited to customizing dense bilayer medicines, our approach uses Additive Manufacturing (AM) to effectively adjust drug release profiles. Focusing on Caffeine and Paracetamol, we found successful processing for both DDM and IM using Caffeine formulation. The high viscosity of Paracetamol formulation posed challenges during DDM processing. Integrating Paracetamol formulation for the over-molding process proved effective, demonstrating IM's versatility in handling complex formulations. Varying infill percentages in DDM tablets led to distinct porosities affecting diverse drug release profiles in DDM-fabricated tablets. In contrast, tablets with high-density structures formed through the over-molding process displayed slower and more uniform release patterns. Combining DDM and IM techniques allows for overcoming the inherent limitations of each technique independently, enabling the production of bilayer tablets with customizable drug release profiles. The study's results offer promising insights into the future of personalized medicine, suggesting new pathways for the development of customized oral dosage forms.

Development of multiple structured extended release tablets via hot melt extrusion and dual-nozzle fused deposition modeling 3D printing

The study aims to fabricate extended release (ER) tablets using a dual-nozzle fused deposition modeling (FDM) three-dimensional (3D) printing technology based on hot melt extrusion (HME), using caffeine as the model compound. Three different ER tablets were developed, which obtained "delayed-release", "rapid-sustained release", and "release-lag-release" properties. Each type of tablet was printed with two different formulations. A novel printing method was employed in this study, which is to push the HME filament from behind with polylactic acid (PLA) to prevent sample damage by gears during the printing process. Powder X-ray diffractometry (PXRD) and differential scanning calorimetry (DSC) results showed that caffeine was predominately amorphous in the final tablets. The dissolution of 3D printed tablets was assessed using a USP-II dissolution apparatus. ER tablets containing PVA dissolved faster than those developed with Kollicoat IR. Overall, this study revealed that ER tablets were successfully manufactured through HME paired with dual-nozzle FDM 3D printing and demonstrated the power of 3D printing in developing multi-layer tablets with complex structures.

Orthogonal Gelations to Synthesize Core-Shell Hydrogels Loaded with Nanoemulsion-Templated Drug Nanoparticles for Versatile Oral Drug Delivery

Hydrophobic active pharmaceutical ingredients (APIs) are ubiquitous in the drug development pipeline, but their poor bioavailability often prevents their translation into drug products. Industrial processes to formulate hydrophobic APIs are expensive, difficult to optimize, and not flexible enough to incorporate customizable drug release profiles into drug products. Here, a novel, dual-responsive gelation process that exploits orthogonal thermo-responsive and ion-responsive gelations is introduced. This one-step "dual gelation" synthesizes core-shell (methylcellulose-alginate) hydrogel particles and encapsulates drug-laden nanoemulsions in the hydrogel matrices. In situ crystallization templates drug nanocrystals inside the polymeric core, while a kinetically stable amorphous solid dispersion is templated in the shell. Drug release is explored as a function of particle geometry, and programmable release is demonstrated for various therapeutic applications including delayed pulsatile release and sequential release of a model fixed-dose combination drug product of ibuprofen and fenofibrate. Independent control over drug loading between the shell and the core is demonstrated. This formulation approach is shown to be a flexible process to develop drug products with biocompatible materials, facile synthesis, and precise drug release performance. This work suggests and applies a novel method to leverage orthogonal gel chemistries to generate functional core-shell hydrogel particles.

Development of a Bilayer Tablet by Fused Deposition Modeling as a Sustained-Release Drug Delivery System

Three-dimensional printing by fused deposition modeling (FDM) coupled with hot-melt extrusion (HME) is a point of convergence of research efforts directed toward the development of personalized dosage forms. In addition to the customization in terms of shapes, sizes, or delivered drug doses, the modulation of drug release profiles is crucial to ensure the superior efficacy and safety of modern 3D-printed medications compared to those of conventional ones. Our work aims to solidify the groundwork for the preparation of 3D-printed tablets that ensure the sustained release of diclofenac sodium. Specifically, we achieved the fast release of a diclofenac sodium dose to allow for the prompt onset of its pharmacological effect, further sustaining by the slow release of another dose to maintain the effect over a prolonged timeframe. In this regard, proper formulation and design strategies (a honeycomb structure for the immediate-release layer and a completely filled structure for the sustained-release layer) were applied. Secondarily, the potential of polyvinyl alcohol to function as a multifaceted polymeric matrix for both the immediate and slow-release layers was explored, with the objective of promoting the real-life applicability of the technique by downsizing the number of materials required to obtain versatile pharmaceutical products. The present study is a step forward in the translation of HME-FDM-3DP into a pharmaceutical manufacturing methodology.

Three-Dimensionally Printed Vaginal Rings: Perceptions of Women and Gynecologists in a Cross-Sectional Survey

Three-dimensional printing technologies can be implemented for the fabrication of personalized vaginal rings (VRs) as an alternative approach to traditional manufacturing. Although several studies have demonstrated the potential of additive manufacturing, there is a lack of knowledge concerning the opinions of patients and clinicians. This study aimed to investigate the perception of women and gynecologists regarding VRs with personalized shapes. The devices were printed with different designs (traditional, "Y", "M", and flat circle) by Fused Deposition Modeling for a cross-sectional survey with 155 participants. Their anticipated opinion was assessed through a questionnaire after a visual/tactile analysis of the VRs. The findings revealed that most women would feel comfortable using some of the 3D-printed VR designs and demonstrated good acceptability for the traditional and two innovative designs. However, women presented multiple preferences when the actual geometry was assessed, which directly related to their age, previous use of the vaginal route, and perception of comfort. In turn, gynecologists favored prescribing traditional and flat circle designs. Overall, although there was a difference in the perception between women and gynecologists, they had a positive opinion of the 3D-printed VRs. Finally, the personalized VRs could lead to an increase in therapeutic adherence, by meeting women's preferences.

3D printed biomedical devices and their applications: A review on state-of-the-art technologies, existing challenges, and future perspectives

3D printing, also known as Additive manufacturing (AM), has emerged as a transformative technology with applications across various industries, including the medical sector. This review paper provides an overview of the current status of AM technology, its challenges, and its application in the medical industry. The paper covers the different types of AM technologies, such as fused deposition modeling, stereolithography, selective laser sintering, digital light processing, binder jetting, and electron beam melting, and their suitability for medical applications. The most commonly used biomedical materials in AM, such as plastic, metal, ceramic, composite, and bio-inks, are also viewed. The challenges of AM technology, such as material selection, accuracy, precision, regulatory compliance, cost and quality control, and standardization, are also discussed. The review also highlights the various applications of AM in the medical sector, including the production of patient-specific surgical guides, prosthetics, orthotics, and implants. Finally, the review highlights the Internet of Medical Things (IoMT) and artificial intelligence (AI) for regulatory frameworks and safety standards for 3D-printed biomedical devices. The review concludes that AM technology can transform the healthcare industry by enabling patients to access more personalized and reasonably priced treatment alternatives. Despite the challenges, integrating AI and IoMT with 3D printing technology is expected to play a vital role in the future of biomedical device applications, leading to further advancements and improvements in patient care. More research is needed to address the challenges and optimize its use for medical applications to utilize AM's potential in the medical industry fully.

Texture analysis – a versatile tool for pharmaceutical evaluation of solid oral dosage forms

In the past few decades, texture analysis (TA) has gained importance as a valuable method for the characterization of solid oral dosage forms. As a result, an increasing number of scientific publications describe the textural methods that evaluate the extremely diverse category of solid pharmaceutical products. Within the current work, the use of texture analysis in the characterization of solid oral dosage forms is summarised with a focus on the evaluation of intermediate and finished oral pharmaceutical products. Several texture methods are reviewed regarding the applications in mechanical characterization, and mucoadhesion testing, but also in estimating the disintegration time and in vivo specific features of oral dosage forms. As there are no pharmacopoeial standards for pharmaceutical products tested through texture analysis, and there are important differences between reported results due to different experimental conditions, the choice of testing protocol and parameters is challenging. Thereby, this work aims to guide the research scientists and quality assurance professionals involved in different stages of drug development into the selection of optimal texture methodologies depending on the product characteristics and quality control needs.

Hard Gelatin Capsules Containing Hot Melt Extruded Solid Crystal Suspension of Carbamazepine for improving dissolution: Preparation and In vitro Evaluation

Aqueous solubility is one of the key parameters for achieving the desired drug concentration in systemic circulation for better therapeutic outcomes. Carbamazepine (CBZ) is practically insoluble in water, is a BCS class II drug, and exhibits dissolution-dependent oral bioavailability. This study explored a novel application of hot-melt extrusion in the manufacture and development of a thermodynamically stable solid crystal suspension (SCS) to improve the solubility and dissolution rate of CBZ. The SCSs were prepared using sugar alcohols, such as mannitol or xylitol, as crystalline carriers. The drug-sugar blend was processed by hot melt extrusion up to 40 % (w/w) drug loading. The extruded SCS was evaluated for drug content, saturation solubility, differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), in vitro release, and stability studies. The physicochemical characterization revealed the highly crystalline existence of pure drug, pure carriers, and extruded SCS. FTIR analysis did not reveal any physical or chemical incompatibilities between the drug and sugar alcohols and showed a homogeneous CBZ distribution within respective crystalline carriers. The SEM micrographs of the solidified SCS revealed the presence of approximately 100 μm crystalline agglomerates. In vitro dissolution and solubility studies showed that the CBZ dissolution rate and solubility were improved significantly from both crystalline carriers for all tested drug loads. The SCSs showed no significant changes in drug content, in vitro release profiles, and thermal characteristics over 3 months of storage at accelerated stability conditions (40±2°C/75±5% RH). As a result, it can be inferred that the SCS strategy can be employed as a contemporary alternative technique to improve the dissolution rate of BCS class II drugs via HME technology.

Twin Screw Melt Granulation: Alternative Approach for Improving Solubility and Permeability of a Non-steroidal Anti-inflammatory Drug Ibuprofen

The current research is focused on investigating the suitability of the twin screw melt granulation (TSMG) approach for improving the solubility of a non-steroidal anti-inflammatory (NSAIDs) drug (ibuprofen), by developing granules using lipid surfactants. The solubility of the drug within the solid lipid excipients (Gelucire® 48/16 and Gelucire® 50/13) was determined by differential scanning calorimetry (DSC). The formulations were developed for drug and lipid ratios of 1:1.5, 1:3, and 1:4.5 using Neusilin® US2 as a solid adsorbent carrier. The solid-state properties of the drug investigated using differential scanning calorimetry (DSC) have revealed the conversion of the drug to an amorphous form for 1:3 and 1:4.5 ratios of formulations confirmed by powder x-ray diffraction analysis (PXRD). Drug-excipient compatibility and formation of no interactions were characterized using Fourier transform infrared spectroscopy (FTIR). The granules with a 1:3 and 1:4.5 ratios of drug and lipid have improved drug dissolution and permeation, attributing to the formation of micellar emulsions. The stability of formulation with a 1:3 ratio of drug and lipid surfactant was preserved when stored in accelerated conditions. However, the formulation with a 1:4.5 ratio of drug and lipid failed to retain the amorphous state evidenced by the recrystallization of the drug. This shows the suitability of TSMG as a single-step continuous manufacturing process for developing melt granules to improve the solubility of poorly water-soluble drug substances.

3D Printing as a Technological Strategy for the Personalized Treatment of Wound Healing

Wound healing is a dynamic process which involves stages of hemostasis, inflammation, proliferation and remodeling. Any error in this process results in abnormal wound healing, generating financial burdens for health systems and even affecting the physical and mental health of the patient. Traditional dressings do not meet the complexities of ideal treatment in all types of wounds. For this reason, in the last decades, different materials for drug delivery and for the treatment of wounds have been proposed reaching novel level of standards, such as 3D printing techniques. The use of natural or synthetic polymers, and the correct design of these printed products loaded with cells and/or combined with active compounds, can generate an effective system for the treatment of wounds, improving the healing process and generating customized dressings according to the patient needs. This manuscript provides a comprehensive review of different types of 3D printing techniques, as well as its use in wound healing and its different stages, including the advantages and limitations of additive manufacturing and future perspectives.

3D printing of pharmaceuticals for disease treatment

Three-dimensional (3D) printing or Additive manufacturing has paved the way for developing and manufacturing pharmaceuticals in a personalized manner for patients with high volume and rare diseases. The traditional pharmaceutical manufacturing process involves the utilization of various excipients to facilitate the stages of blending, mixing, pressing, releasing, and packaging. In some cases, these excipients cause serious side effects to the patients. The 3D printing of pharmaceutical manufacturing avoids the need for excessive excipients. The two major components of a 3D printed tablet or dosage form are polymer matrix and drug component alone. Hence the usage of the 3D printed dosage forms for disease treatment will avoid unwanted side effects and provide higher therapeutic efficacy. With respect to the benefits of the 3D printed pharmaceuticals, the present review was constructed by discussing the role of 3D printing in producing formulations of various dosage forms such as fast and slow releasing, buccal delivery, and localized delivery. The dosage forms are polymeric tablets, nanoparticles, scaffolds, and films employed for treating different diseases.

Preparation and in vitro evaluation of hot-melt extruded pectin-based pellets containing ketoprofen for colon targeting

This work developed high drug-load pellets for colon targeting in minimal steps by coupling hot-melt extrusion (HME) with a die-surface cutting pelletizer, offering a potential continuous pellet manufacturing process. Ketoprofen (KTP) was selected as a model drug for this study due to its thermal stability and severe upper gastrointestinal side effects. Low and high methoxyl grade pectins were the enzyme-triggered release matrix, and hydroxypropyl methylcellulose (HME 4 M/HME 100LV) was used as a premature release-retarding agent. The powder X-ray diffraction technique and the differential scanning calorimetry results revealed that KTP exists in the solid-solution state within the polymeric matrix after the HME step. The scanning electron micrographs of the fabricated pellets showed a smooth surface without any cracks. The lead formulation showed the lowest premature drug release (∼13%) with an extended KTP release profile over a 24 h period in the presence and absence of the release-triggering enzyme. The lead formulation was stable for 3 months at accelerated stability conditions (40 °C/75 ± 5% RH) concerning drug content, in vitro release, and thermal characteristics. In summary, coupling HME and pelletization processes could be a promising technology for developing colon-targeted drug delivery systems.