3D printed extended release tablets for once daily use: An in vitro and in vivo evaluation study for a personalized solid dosage form

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.

3D Printed Personalized Colon-targeted Tablets: A Novel Approach in Ulcerative Colitis Management

Ulcerative colitis (UC) and Crohn's disease (CD) are two types of idiopathic inflammatory bowel disease (IBD) that are increasing in frequency and incidence worldwide, particularly in highly industrialized countries. Conventional tablets struggle to effectively deliver anti-inflammatory drugs since the inflammation is localized in different areas of the colon in each patient. The goal of 3D printing technology in pharmaceutics is to create personalized drug delivery systems (DDS) that are tailored to each individual's specific needs. This review provides an overview of existing 3D printing processes, with a focus on extrusion-based technologies, which have received the most attention. Personalized pharmaceutical products offer numerous benefits to patients worldwide, and 3D printing technology is becoming more affordable every day. Custom manufacturing of 3D printed tablets provides innovative ideas for developing a tailored colon DDS. In the future, 3D printing could be used to manufacture personalized tablets for UC patients based on the location of inflammation in the colon, resulting in improved therapeutic outcomes and a better quality of life.

Development of Subdermal Implants Using Direct Powder Extrusion 3D Printing and Hot-Melt Extrusion Technologies

Implants are drug delivery platforms that consist of a drug-polymer matrix with the ability of providing a localized and efficient controlled release of the drug with minimal side effects and achievement of the desired therapeutic outcomes with low drug loadings. Direct powder extrusion (DPE) 3D printing technology involves the extrusion of material through a nozzle of the printer in the form of pellets or powder. The present study aimed at investigating the use of the CELLINK BIO X™ bioprinter using DPE 3D printing technique to fabricate and evaluate the impact of different shapes (cuboid, cylinder, and tube) of raloxifene hydrochloride (RFH)-loaded subdermal implants on the release of RFH from the implants. This study further evaluated the impact of different processing techniques, viz., hot-melt extrusion (HME) technology vs. DPE 3D printing technique, on the release of RFH from the implants fabricated by each processing technique. All the fabricated implants were characterized by XRD, DSC, SEM, and FTIR, and evaluated for their water uptake, mass loss, and in vitro RFH release. The current study successfully demonstrated a great opportunity of controlling and/or tuning the release of RFH from the subdermal implants by altering the implant shape, and hence surface area, and could be a great contribution and/or addition to the personalization of medicines and improvement of patient compliance.

A comparison of droplet deposition modelling, fused filament fabrication, and injection moulding for the production of oral dosage forms containing hydrochlorothiazide

Additive manufacturing (AM) possesses a transformative potential to revolutionize personalized medicine fabrication. Fused filament fabrication (FFF), an advanced AM technique, enables the development of tailored medicines with customizable dosages and controlled release properties. Nevertheless, filament prerequisites impose material limitations and present considerable challenges, necessitating a comprehensive evaluation of mechanical, rheological, and thermal characteristics to circumvent complications during the FFF process. Droplet deposition modeling (DDM), an innovative AM approach derived from injection molding (IM) technology, processes granulate feedstock to facilitate the production of personalized medicines. This study delves into the effects of FFF, DDM, and IM techniques on the release profiles of Hydrochlorothiazide, a widely employed drug for hypertension and edema treatment. By varying infill density, the investigation assesses the manufactured tablets using DDM and FFF methods. Our findings show that tablets made with FFF and DDM with identical infill densities had distinct microstructures, resulting in variable drug release profiles. Decreasing the infill densities resulted in higher sample porosity, leading to an accelerated drug release rate. A comparative analysis of drug release profiles from DDM and IM fabricated tablets demonstrated notable differences, despite DDM's origins in injection molding technology. This comprehensive study underscores the significance of not only infill densities but also the choice of manufacturing technique, as both factors can profoundly influence drug release profiles. By shedding light on these considerations, the research contributes to the ongoing advancement of personalized medicine through additive manufacturing technologies.

3D printing of microencapsulated Lactobacillus rhamnosus for oral delivery

3D Printing is an innovative technology within the pharma and food industries that allows the design and manufacturing of novel delivery systems. Orally safe delivery of probiotics to the gastrointestinal tract faces several challenges regarding bacterial viability, in addition to comply with commercial and regulatory standpoints. Lactobacillus rhamnosus CNCM I-4036 (Lr) was microencapsulated in generally recognised as safe (GRAS) proteins, and then assessed for robocasting 3D printing. Microparticles (MP-Lr) were developed and characterised, prior to being 3D printed with pharmaceutical excipients. MP-Lr showed a size of 12.3 ± 4.1 µm and a non-uniform wrinkled surface determined by Scanning Electron Microscopy (SEM). Bacterial quantification by plate counting accounted for 8.68 ±0.6 CFU/g of live bacteria encapsulated within. Formulations were able to keep the bacterial dose constant upon contact with gastric and intestinal pH. Printlets consisted in oval-shape formulations (15 mm × 8 mm × 3.2 mm) of ca. 370 mg of total weight, with a uniform surface. After the 3D printing process, bacterial viability remained even as MP-Lr protected bacteria alongside the process (log reduction of 0.52, p>0.05) in comparison with non-encapsulated probiotic (log reduction of 3.05). Moreover, microparticle size was not altered during the 3D printing process. We confirmed the success of this technology for developing an orally safe formulation, GRAS category, of microencapsulated Lr for gastrointestinal vehiculation.

Fabrication of timed-release indomethacin core-shell tablets for chronotherapeutic drug delivery using dual nozzle Fused Deposition Modeling (FDM) 3D printing

In the present study, timed-release indomethacin tablets, releasing drug after predetermined lag times, were developed for the effective treatment of early morning stiffness in rheumatoid arthritis using two-nozzle fused deposition modeling (FDM) 3D printing with a Bowden extruder. The developed core-shell tablets consisted of a drug-containing core and release-regulating shell with different designed thicknesses (i.e., 0.4 mm, 0.6 mm, 0.8 mm). The filaments to fabricate cores and shells were prepared using hot-melt extrusion (HME), and different filament compositions were formulated for core tablets and screened for rapid release and printability. Eventually, the HPMCAS-based formulation comprised a core tablet enclosed by a shell of Affinisol™ 15LV, a swellable polymer. During 3D printing, one nozzle was dedicated to printing core tablets loaded with indomethacin, and the other nozzle was dedicated to printing shells, making a whole structure produced at once without inconvenient filament change and nozzle cleanout. The mechanical properties of filaments were compared using a texture analyzer. The core-shell tablets were characterized for dissolution profiles and physical attributes (e.g., dimension, friability, hardness). SEM image indicated a smooth and complete surface of the core-shell tablets. The tablets showed 4-8 hours of lag depending on the shell thicknesses and released most of the drugs in 3 hours, regardless of the shell thicknesses. The core-shell tablets showed high reproducibility but exhibited low dimensional accuracy in the shell thickness. This study explored the suitability of using two-nozzle FDM 3D printing with Bowden extrusion for producing personalized chronotherapeutic core-shell tablets and discussed possible challenges that needed to be considered for a successful printing process using this technology.

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.

Development and Evaluation of Self-Emulsifying Drug-Delivery System-Based Tablets for Simvastatin, a BCS Class II Drug

Background

Self-emulsifying drug-delivery systems (SEDDSs) are designed to improve the oral bioavailability of poorly water-soluble drugs. This study aimed at formulating and characterization of SEDDS-based tablets for simvastatin using castor and olive oils as solvents and Tween 60 as surfactant.

Methods

The liquids were adsorbed on microcrystalline cellulose, and all developed formulations were compressed using 10.5 mm shallow concave round punches.

Results

The resulting tablets were evaluated for different quality-control parameters at pre- and postcompression levels. Simvastatin showed better solubility in a mixture of oils and Tween 60 (10:1). All the developed formulations showed lower self-emulsification time (˂200 seconds) and higher cloud point (˃60°C). They were free of physical defects and had drug content within the acceptable range (98.5%-101%). The crushing strength of all formulations was in the range of 58-96 N, and the results of the friability test were within the range of USP (≤1). Disintegration time was within the official limits (NMT 15 min), and complete drug release was achieved within 30 min.

Conclusion

Using commonly available excipients and machinery, SEDDS-based tablets with better dissolution profile and bioavailability can be prepared by direct compression. These S-SEDDSs could be a better alternative to conventional tablets of simvastatin.

Formulation Development and Characterization of pH Responsive Polymeric Nano-Pharmaceuticals for Targeted Delivery of Anti-Cancer Drug (Methotrexate)

Oral administration of pH sensitive/stimuli responsive nanoparticles are gaining importance because of the limited side effects, minimum dose and controlled drug release. The objective of this study was to develop and evaluate pH sensitive polymeric nanoparticles for methotrexate with the aim to maximize the drug release at target site. In the presented study, pH sensitive polymeric nanoparticles of methotrexate were developed through modified solvent evaporation technique using polymer Eudragit S100. Different process parameters like drug to polymer ratio, speed of sonication, concentration of surfactant and time of sonication were optimized by evaluating their effects on particle size, PDI, zeta potential, entrapment/encapsulation efficiency. The developed formulations were evaluated for their size, polydispersity (PDI), zeta potential, encapsulation efficiency, XRD, scanning electron microscopy, in-vitro drug release and stability studies. Best results were obtained with poloxamer-407 and PVA and were selected as surfactants. Physicochemical characterization of the developed formulations showed that the particle size lies in the range 165.7 ± 1.85–330.4 ± 4.19, PDI 0.119 ± 0.02–0.235 ± 0.008, zeta potential −0.163 ± 0.11–−5.64 ± 0.36 mV, and encapsulation efficiency more than 61%. The results of scanning electron microscopy revealed that nanoparticles have regular geometry with spherical shape. Initially the drug release occur through diffusion followed by erosion. The present studies showed that MTX-ES100 nanoparticles prepared during this study have the desired physicochemical properties, surface morphology and release characteristics used to target the desired organs.

3D printing of pharmaceutical oral solid dosage forms by fused deposition: the enhancement of printability using plasticised HPMCAS

3D printing (3DP) by fused deposition modelling (FDM) is one of the most extensively developed methods in additive manufacturing. Optimizing printability by improving feedability, nozzle extrusion, and layer deposition is crucial for manufacturing solid oral dosage forms with desirable properties. This work aimed to use HPMCAS (Affinisol^TM HPMCAS 716) to prepare filaments for FDM-3DP using hot-melt extrusion (HME). It explored and demonstrated the effect of HME-filament composition and fabrication on printability by evaluating thermal, mechanical, and thermo-rheological properties. It also showed that the HME-Polymer filament composition used in FDM-3DP manufacture of oral solid dosage forms provides a tailored drug release profile. HME (HAAKE MiniLab) and FDM-3DP (MakerBot) were used to prepare HME-filaments and printed objects, respectively. Two diverse ways of improving the mechanical properties of HME-filaments were deduced by changing the formulation to enable feeding through the roller gears of the printer nozzle. These include plasticizing the polymer and adding an insoluble structuring agent (talc) into the formulation. Experimental feedability was predicted using texture analysis results was a function of PEG concentration, and glass-transition temperature (T_g) values of HME-filaments. The effect of high HME screw speed (100 rpm) resulted in inhomogeneity of HME-filament, which resulted in inconsistency of the printer nozzle extrudate and printed layers. The variability of the glass-transition temperature (T_g) of the HME-filament supported by scanning electron microscopy (SEM) images of nozzle extrudates and the lateral wall of the printed tablet helped explain this result. The melt viscosity of HPMCAS formulations was investigated using a capillary rheometer. The high viscosity of unplasticized HPMCAS was concluded to be an additional restriction for nozzle extrusion. The plasticization of HPMCAS and the addition of talc into the formulation were shown to improve thickness consistency of printed layers (using homogeneous HME-filaments). A good correlation (R²=0.9546) between the solidification threshold (low-frequency oscillation test determined by parallel-plate rheometer) and T_g of HME-filaments was also established. Drug-loaded and placebo HPMCAS-based formulations were shown to be successfully printed, with the former providing tailored drug release profiles based on variation of internal geometry (infill).