Quality by design approach for fabrication of extended-release buccal films for xerostomia employing hot-melt extrusion technology

The study endeavors the fabrication of extended-release adipic acid (APA) buccal films employing a quality by design (QbD) approach. The films intended for the treatment of xerostomia were developed utilizing hot-melt extrusion technology. The patient-centered quality target product profile was created, and the critical quality attributes were identified accordingly. Three early-stage formulation development trials, complemented by risk assessment aligned the formulation and process parameters with the product quality standards. Employing a D-optimal mixture design, the formulations were systematically optimized by evaluating three formulation variables: amount of the release-controlling polymer Eudragit® (E RSPO), bioadhesive agent Carbopol® (CBP 971P), and pore forming agent polyethylene glycol (PEG 1500) as independent variables, and % APA release in 1, 4 and 8 h as responses. Using design of experiment software (Design-Expert®), a total of 16 experimental runs were computed and extruded using a Thermofisher ScientificTM twin screw extruder. All films exhibited acceptable content uniformity and extended-release profiles with the potential for releasing APA for at least 8 h. Films containing 30% E RSPO, 10% CBP 971P, and 20% PEG 1500 released 88.6% APA in 8 h. Increasing the CBP concentration enhanced adhesiveness and swelling capacities while decreasing E RSPO concentration yielded films with higher mechanical strength. The release kinetics fitted well into Higuchi and Krosmeyer-Peppas models indicating a Fickian diffusion release mechanism.

Formulation and evaluation of inhaled Sildenafil-loaded PLGA microparticles for treatment of pulmonary arterial hypertension (PAH): A novel high drug loaded formulation and scalable process via hot melt extrusion technology (Part Ⅰ)

In recent years, several techniques were employed to develop a local sustained pulmonary delivery of sildenafil citrate (SC) as an alternative for the intravenous and oral treatment of pulmonary arterial hypertension (PAH). Most of these methods, however, need to be improved due to limitations of scalability, low yield production, low drug loading, and stability issues. In this study, we report the use of hot-melt extrusion (HME) as a scalable process for making Poly (lactic-co-glycolic acid) (PLGA) microparticles with high SC load. The prepared particles were tested in vitro for local drug delivery to the lungs by inhalation. Sodium bicarbonate was included as a porogen in the formulation to make the particles more brittle and to impart favorable aerodynamic properties. Six formulations were prepared with different formulation compositions. Laser diffraction analysis was used to estimate the geometric particle size distribution of the microparticles. In-vitro aerodynamic performance was evaluated by the next-generation cascade impactor (NGI). It was reported in terms of an emitted dose (ED), an emitted fraction (EF%), a respirable fraction (RF%), a fine particle fraction (FPF%), a mass median aerodynamic diameter (MMAD), and geometric standard deviation (GSD). The formulations have also been characterized for surface morphology, entrapment efficiency, drug load, and in-vitro drug release. The results demonstrated that PLGA microparticles have a mean geometric particle size between 6 and 14 µm, entrapment efficiency of 77 to 89 %, and SC load between 17 and 33 % w/w. Fifteen percent of entrapped sildenafil was released over 24 h from the PLGA microparticles, and seventy percent over 7 days. The aerodynamic properties included fine particle fraction ranging between 19 and 33 % and an average mass median aerodynamic diameter of 6-13 µm.

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.

Hot-Melt Extrusion: from Theory to Application in Pharmaceutical Formulation-Where Are We Now?

Hot-melt extrusion (HME) is a globally recognized, robust, effective technology that enhances the bioavailability of poorly soluble active pharmaceutical ingredients and offers an efficient continuous manufacturing process. The twin-screw extruder (TSE) offers an extremely resourceful customizable mixer that is used for continuous compounding and granulation by using different combinations of conveying elements, kneading elements (forward and reverse configuration), and distributive mixing elements. TSE is thus efficiently utilized for dry, wet, or melt granulation not only to manufacture dosage forms such as tablets, capsules, or granule-filled sachets, but also for designing novel formulations such as dry powder inhalers, drying units for granules, nanoextrusion, 3D printing, complexation, and amorphous solid dispersions. Over the past decades, combined academic and pharmaceutical industry collaborations have driven novel innovations for HME technology, which has resulted in a substantial increase in published articles and patents. This article summarizes the challenges and models for executing HME scale-up. Additionally, it covers the benefits of continuous manufacturing, process analytical technology (PAT) considerations, and regulatory requirements. In summary, this well-designed review builds upon our earlier publication, probing deeper into the potential of twin-screw extruders (TSE) for various new applications.

Development and Evaluation of Polymeric Mixed Micelles Prepared using Hot-Melt Extrusion for Extended Delivery of Poorly Water-Soluble Drugs

The poor aqueous solubility is a well-recognized restriction for the clinical application of many drug molecules. Micelles delivery system provides a promising strategy for the solubility enhancement of hydrophobic drugs. This study developed and evaluated different polymeric mixed micelles prepared using hot-melt extrusion coupled hydration method to improve the solubility and extend the release of the model drug ibuprofen (IBP). The physicochemical properties of the prepared formulations were characterized in terms of particle size, polydispersity index, zeta potential, surface morphology, crystallinity, encapsulation efficiency, drug content, in vitro drug release, dilution stability, and storage stability. Soluplus®/poloxamer 407, Soluplus®/poloxamer 188, and Soluplus®/TPGS mixed micelles had average particle sizes of 86.2 ± 2.8, 89.6 ± 4.2, and 102.5 ± 3.13 nm, respectively with adequate encapsulation efficiencies of 80% to 92%. Differential scanning calorimetry studies confirmed that the IBP molecules were dissolved in the polymers in an amorphous state. The in vitro release results revealed that the IBP-loaded mixed micelles presented extended-release behavior compared to the free drug. In addition, the developed polymeric mixed micelles remained stable upon dilution and one-month storage. These results demonstrated that the hot-melt extrusion coupling hydration method could be a promising, effective, and environment-friendly manufacturing technique for the scale-up production of polymeric mixed micelles to deliver insoluble drugs.

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 Comparative Assessment of Cocrystal and Amorphous Solid Dispersion Printlets Developed by Hot Melt Extrusion Paired Fused Deposition Modeling for Dissolution Enhancement and Stability of Ibuprofen

The primary focus of the research is to study the role of cocrystal and amorphous solid dispersion approaches for enhancing solubility and preserving the stability of a poorly soluble drug, i.e., ibuprofen (IBP). First, the solvent-assisted grinding approach determined the optimum molar ratio of the drug and the coformer (nicotinamide (NIC)). Later, the polymeric filaments of cocrystals and amorphous solid dispersions were developed using the hot melt extrusion (HME) process, and the printlets were fabricated using the fused deposition modeling (FDM) additive manufacturing process. In addition, the obtained filaments were also milled and compressed into tablets as reference samples. The formation of cocrystals and amorphous solid dispersions was evaluated and confirmed using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffraction (PXRD) analysis. The drug release profiles of 3D printlets with 50% infill were found to be faster and are in line with the release profiles of compressed tablets. In addition, the 3D-printed cocrystal formulation was stable for 6 months at accelerated conditions. However, the 3D printlets of amorphous solid dispersions and compressed tablets failed to retain stability attributed to the recrystallization of the drug and loss in tablet mechanical properties. This shows the suitability of a cocrystal platform as a novel approach for developing stable formulations of poorly soluble drug substances over amorphous solid dispersions.

Twin Screw Melt Granulation: A Single Step Approach for Developing Self-Emulsifying Drug Delivery System for Lipophilic Drugs

The current research aims to improve the solubility of the poorly soluble drug, i.e., ibuprofen, by developing self-emulsifying drug delivery systems (SEDDS) utilizing a twin screw melt granulation (TSMG) approach. Gelucire® 44/14, Gelucire® 48/16, and Transcutol® HP were screened as suitable excipients for developing the SEDDS formulations. Initially, liquid SEDDS (L-SEDDS) were developed with oil concentrations between 20-50% w/w and surfactant to co-surfactant ratios of 2:1, 4:1, 6:1. The stable formulations of L-SEDDS were transformed into solid SEDDS (S-SEDDS) using a suitable adsorbent carrier and compressed into tablets (T-SEDDS). The S-SEDDS has improved flow, drug release profiles, and permeability compared to pure drugs. The existence of the drug in an amorphous state was confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction analysis (PXRD). The formulations with 20% w/w and 30% w/w of oil concentration and a 4:1 ratio of surfactant to co-surfactant have resulted in a stable homogeneous emulsion with a globule size of 14.67 ± 0.23 nm and 18.54 ± 0.55 nm. The compressed tablets were found stable after six months of storage at accelerated and long-term conditions. This shows the suitability of the TSMG approach as a single-step continuous manufacturing process for developing S-SEDDS formulations.

Formulation and processing of solid self-emulsifying drug delivery systems (HME S-SEDDS): A single-step manufacturing process via hot-melt extrusion technology through response surface methodology

The objective of the current study is the formulation development and manufacturing of solid self-emulsifying drug delivery systems (HME S-SEDDS) via a single-step continuous hot-melt extrusion (HME) process. For this study, poorly soluble fenofibrate was selected as a model drug. From the results of pre-formulation studies, Compritol® HD5 ATO, Gelucire® 48/16, and Capmul® GMO-50 were selected as oil, surfactant and co-surfactant respectively for manufacturing of HME S-SEDDS. Neusilin® US2 was selected as a solid carrier. The design of experiments (response surface methodology) was employed to prepare formulations via a continuous HME process. The formulations were evaluated for emulsifying properties, crystallinity, stability, flow properties and drug release characteristics. The prepared HME S-SEDDS showed excellent flow properties, and the resultant emulsions were stable. The globule size of the optimized formulation was 269.6 nm. The DSC and XRD studies revealed the amorphous nature of the formulation and FTIR studies showed no significant interaction between fenofibrate and excipients. The drug release studies showed significant (p < 0.05) improvement in solubility compared to the pure drug (DE15 = 45.04 for the optimized formulation), as >90% of drug release was observed within 15 min. The stability studies for the optimized formulation were conducted for 3 months at 40 °C/75% RH.

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.

Influence of Poloxamer on the Dissolution and Stability of Hot-Melt Extrusion-Based Amorphous Solid Dispersions Using Design of Experiments

The current study aimed to see the effects of poloxamer P407 on the dissolution performance of hydroxypropyl methylcellulose acetate succinate (AquaSolve™ HPMC-AS HG)-based amorphous solid dispersions (ASD). A weakly acidic, poorly water-soluble active pharmaceutical ingredient (API), mefenamic acid (MA), was selected as a model drug. Thermal investigations, including thermogravimetry (TG) and differential scanning calorimetry (DSC), were conducted for raw materials and physical mixtures as a part of the pre-formulation studies and later to characterize the extruded filaments. The API was blended with the polymers using a twin shell V-blender for 10 min and then extruded using an 11-mm twin-screw co-rotating extruder. Scanning electron microscopy (SEM) was used to study the morphology of the extruded filaments. Furthermore, Fourier-transform infrared spectroscopy (FT-IR) was performed to check the intermolecular interactions of the components. Finally, to assess the in vitro drug release of the ASDs, dissolution testing was conducted in phosphate buffer (0.1 M, pH 7.4) and hydrochloric acid-potassium chloride (HCl-KCl) buffer (0.1 M, pH 1.2). The DSC studies confirmed the formation of the ASDs, and the drug content of the extruded filaments was observed to be within an acceptable range. Furthermore, the study concluded that the formulations containing poloxamer P407 exhibited a significant increase in dissolution performance compared to the filaments with only HPMC-AS HG (at pH 7.4). In addition, the optimized formulation, F3, was stable for over 3 months when exposed to accelerated stability studies.

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.

Disulfiram 3D printed film produced via hot-melt extrusion techniques as a potential anticervical cancer candidate

Cervical cancer is known globally as one of the most common health problems in women. Indeed, one of the most convenient approaches for its treatment is an appropriate bioadhesive vaginal film. This approach provides a local treatment modality, which inevitably decreases dosing frequency and improves patient compliance. Recently, disulfiram (DSF) has been investigated and demonstrated to possess anticervical cancer activity; therefore, it is employed in this work. The current study aimed to produce a novel, personalized three-dimensional (3D) printed DSF extended-release film using the hot-melt extrusion (HME) and 3D printing technologies. The optimization of the formulation composition and the HME and 3D printing processing temperatures was an important factor for overcoming the DSF heat-sensitivity issue. In addition, the 3D printing speed was specifically the most crucial parameter for alleviating heat-sensitivity concerns, which led to the production of films (F1 and F2) with an acceptable DSF content and good mechanical properties. The bioadhesion film study using sheep cervical tissue indicated a reasonable adhesive peak force (N) of 0.24 ± 0.08 for F1 and 0.40 ± 0.09 for F2, while the work of adhesion (N.mm) for F1 and F2 was 0.28 ± 0.14 and 0.54 ± 0.14, respectively. Moreover, the cumulative in vitro release data indicated that the printed films released DSF for up to 24 h. HME-coupled 3D printing successfully produced a patient-centric and personalized DSF extended-release vaginal film with a reduced dose and longer dosing interval.

Recent Advances in the Applications of Additive Manufacturing (3D Printing) in Drug Delivery: A Comprehensive Review

There has been a tremendous increase in the investigations of three-dimensional (3D) printing for biomedical and pharmaceutical applications, and drug delivery in particular, ever since the US FDA approved the first 3D printed medicine, SPRITAM® (levetiracetam) in 2015. Three-dimensional printing, also known as additive manufacturing, involves various manufacturing techniques like fused-deposition modeling, 3D inkjet, stereolithography, direct powder extrusion, and selective laser sintering, among other 3D printing techniques, which are based on the digitally controlled layer-by-layer deposition of materials to form various geometries of printlets. In contrast to conventional manufacturing methods, 3D printing technologies provide the unique and important opportunity for the fabrication of personalized dosage forms, which is an important aspect in addressing diverse patient medical needs. There is however the need to speed up the use of 3D printing in the biopharmaceutical industry and clinical settings, and this can be made possible through the integration of modern technologies like artificial intelligence, machine learning, and Internet of Things, into additive manufacturing. This will lead to less human involvement and expertise, independent, streamlined, and intelligent production of personalized medicines. Four-dimensional (4D) printing is another important additive manufacturing technique similar to 3D printing, but adds a 4th dimension defined as time, to the printing. This paper aims to give a detailed review of the applications and principles of operation of various 3D printing technologies in drug delivery, and the materials used in 3D printing, and highlight the challenges and opportunities of additive manufacturing, while introducing the concept of 4D printing and its pharmaceutical applications.

Development and Characterization of Different Dosage Forms of Nifedipine/Indomethacin Fixed-Dose Combinations

Studies have shown that 40 individuals out of 100,000 are diagnosed with rheumatoid arthritis (RA) yearly, with a total of 1.3 million in the United States. Furthermore, the impact of RA in some cases can extend to cardiovascular diseases (CVD), as the studies showed that 84% of RA patients are at risk of developing hypertension. This study aims to design and develop different dosage forms (capsule-in-capsule and three-dimensional (3D) printed tablet) of nifedipine/indomethacin fixed-dose combination (FDC). The hot-melt extrusion (HME) was utilized alone and with fused deposition modeling (FDM) techniques The developed dosage forms were intended to provide delayed-extended and immediate release profiles for indomethacin and nifedipine, respectively. FDC dosage forms were successfully developed and characterized. Nifedipine formulations showed significant improvement in release profiles, having 94% of the drug release at 30 minutes compared with pure nifedipine, which had a percent release of 2%. Furthermore, the release of indomethacin was successfully delayed at a pH of 1.2 and extended at a pH of 6.8. Differential scanning calorimetry results showed endothermic crystalline peaks at 165 °C and 176 °C for indomethacin and nifedipine, respectively. Moreover, the thermal analysis of all formulations showed the absence of the endothermic peaks indicating complete solubilization of indomethacin and nifedipine in the polymeric carriers. All formulations had post-processing drug content in the range of 95% to 98%. Moreover, results from the stability study showed that all formulations were able to remain chemically and physically stable with no signs of recrystallization or degradation. The designed FDC dosage forms could improve the quality of life by enhancing patient compliance and preventing the need for polypharmacy.

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.

Design and optimization of ciprofloxacin hydrochloride biodegradable 3D printed ocular inserts: Full factorial design and in-vitro and ex-vivo evaluations: Part II

Coupling hot-melt extrusion (HME) with fused deposition modeling three-dimensional printing (FDM-3DP) can facilitate the fabrication of tailored, patient-centered, and complex-shaped ocular dosage forms. We fabricated ciprofloxacin HCl ocular inserts by coupling high-throughput, solvent-free, and continuous HME with FDM-3DP. Insert fabrication utilized biocompatible, biodegradable, bioadhesive Klucel™ hydroxypropyl cellulose polymer, subjected to distinct FDM-3DP processing parameters, utilizing a design of experiment approach to achieve a tailored release profile. We determined the drug content, thermal properties, drug-excipient compatibility, surface morphology, in vitro release, antibacterial activity, ex-vivo transcorneal permeation, and stability of inserts. An inverse relationship was noted between insert thickness, infill density, and drug release rate. The optimized design demonstrated an amorphous solid dispersion with an extended-release profile over 24 h, no physical or chemical incompatibility, excellent mucoadhesive strength, smooth surface, lack of bacterial growth (Pseudomonas aeruginosa) in all release samples, and prolonged transcorneal drug flux compared with commercial eye drops and immediate-release inserts. The designed inserts were stable at room temperature considering drug content, thermal behavior, and release profile over three months. Overall, the fabricated insert could reduce administration frequency to once-daily dosing, affording a promising topical delivery platform with prolonged antibacterial activity and superior therapeutic outcomes for managing ocular bacterial infections.

Formulation development and in Vitro-Ex vivo characterization of hot-melt extruded ciprofloxacin hydrochloride inserts for ocular applications: Part I

This study developed, optimized, characterized, and evaluated bioadhesive, hot-melt extruded (HME), extended-release ocular inserts containing ciprofloxacin hydrochloride (CIP-HCL) to improve the therapeutic outcomes of ocular bacterial infections. The inserts were fabricated with FDA-approved biocompatible, biodegradable, and bioadhesive polymers that were tuned in different ratios to achieve a sustained release profile. The results revealed an inverse relationship between the Klucel™ hydroxypropyl cellulose (HPC, 140,000 Da) concentration and drug release and extended-release profile over 24 h. The CIP-HCL-HME inserts presented stable drug content, thermal behavior, surface pH, and release profiles over three months of room-temperature storage and demonstrated adequate mucoadhesive strength. SEM micrographs revealed a smooth surface. Bacterial growth was not observed on the samples during the in vitro release experiment (0.5-24 h), indicating that a minimum inhibitory concentration (MIC) of 90 against Pseudomonas aeruginosa was achieved. Ex vivo transcorneal permeation studies using excised rabbit corneas revealed that the prepared ocular inserts prolonged the transcorneal flux of the drug compared to commercial eye drops and immediate-release inserts and could reduce the administration frequency to once daily. Therefore, the inserts could increase patient compliance and exhibited prolonged antibacterial activity and thus could provide better therapeutic outcomes against ocular bacterial infections.

Investigation of hot melt extrusion process parameters on solubility and tabletability of atorvastatin calcium in presence of Neusilin® US2

Reports in the literature indicate that hot-melt extrusion (HME) processing techniques could alter the mechanical properties of the pharmaceutical physical blend, which may alter successful processing during tableting. The aim of this study was to evaluate whether HME processing conditions have an impact on the tabletability of Atorvastatin calcium trihydrate (ATR) in the presence of Neusilin® US2 (NUS2). ATR drug load of 25% was mixed with 75% of NUS2 and extruded using two screw configurations, screw speeds, and feed rates. Solid-state thermal analysis showed that ATR transformed to an amorphous form which led to improved solubility. ATR tabletability was affected positively by screw configuration that had no shearing and mixing force. SEM analysis indicated that a conveying screw configuration preserved the spherical nature of NUS2, thus improving ATR tabletability. This novel study demonstrates the significance of changing and monitoring the HME process parameters, which impact the materials' mechanical properties and may prevent adverse outcomes during tableting.

Hot-Melt Extrusion-Based Fused Deposition Modeling 3D Printing of Atorvastatin Calcium Tablets: Impact of Shape and Infill Density on Printability and Performance

The main objective of the current research was to investigate the effect of tablet shapes (heart-shaped and round tablets) and infill densities (50% and 100%) on the drug release profiles of 3D printed tablets prepared by hot-melt extrusion paired with fused deposition modeling techniques. Drug-loaded filaments of 1.5 mm and 2.5 mm diameters were extruded using a Process 11 mm hot-melt extruder employing atorvastatin calcium as a model drug and Kollicoat® IR, Kollidon® VA64, Kollidon® 12PF, and Kolliphor® P407 as hydrophilic polymers. Filaments of Kollicoat® IR in combination with Kollidon® VA64/Kollidon® 12PF has resulted in successful printing of immediate release tablets. The mechanical properties of drug-loaded filaments were evaluated using a 3-point bend test and stiffness test. The transformation of a crystalline drug to an amorphous form and the absence of drug-polymer interactions were confirmed by differential scanning calorimetry and Fourier transform infrared spectroscopy, respectively. The effect of infill density on drug release profiles was greater than that of tablet shape. The stability of 3D printed tablets was preserved even after storage under accelerated conditions (40 ± 2°C and 75 ± 5% RH) for 6 months. Thus, the 3D printing process of hot-melt extrusion paired with fused deposition modeling serves as an alternative manufacturing approach for developing patient-focused doses.