Recent Progress in Drug Release Testing Methods of Biopolymeric Particulate System

Zinc Acetate as a Cross-Linking Agent in the Development of Enteric Microcapsules for Posaconazole

Background/Objectives: Posaconazole is an antifungal agent from triazoles with variable bioavailability. To avoid its irregular absorption caused by gastric conditions and ensure more repeatable pharmacokinetic enabling the maximization of its absorption regardless of food intake without the need to administer multiple doses, can be provided by the technology of enteric drug preparations. The cross-linking of polysaccharide polymers with divalent and trivalent cations enables multi-unit formulations to be obtained that prevent drug absorption in the stomach. Microcapsules, as an example of multi-unit drug dosage forms, provide more predictable gastric emptying, depending on nutritional status, and spread extensively throughout the gastrointestinal tract. Methods: Therefore, the utilization of zinc acetate for the cross-linking of the alginate and pectin mixture was evaluated. The obtained formulations were evaluated for the impact of cross-linking process and pectin's presence on their pharmaceutical, mucoadhesive, physicochemical and antifungal properties. Results: It was shown that cross-linked microcapsules by zinc acetate provided delayed posaconazole release. Additionally, the cross-linking process with Zn2+ ions significantly enhanced antifungal activity against the analyzed Candida strains. It was observed that pectin content in the formulation enhanced the swelling ability in an intestinal condition and increased the mucoadhesive properties of drug-loaded formulations to the intestinal mucosa.

Dexamethasone-loaded platelet-inspired nanoparticles improve intracortical microelectrode recording performance

Long-term robust intracortical microelectrode (IME) neural recording quality is negatively affected by the neuroinflammatory response following microelectrode insertion. This adversely impacts brain-machine interface (BMI) performance for patients with neurological disorders or amputations. Recent studies suggest that the leakage of blood-brain barrier (BBB) and microhemorrhage caused by the IME insertions lead to the increased neuroinflammation and reduced neural recording performance. Additionally, a sustained presence of activated platelets and coagulation factors is found near the insertion site. Thus, we hypothesized that the systemic administration of dexamethasone sodium phosphate-loaded platelet-inspired nanoparticle (SPPINDEX) can improve the neural recording performance of intracortical microelectrodes (IMEs) by promoting hemostasis, facilitating blood-brain barrier (BBB) healing, and achieving implant-targeted drug delivery. Leveraging the hemostatic and coagulation factor-binding properties of the platelet-inspired nanoparticle (PIN) drug delivery platform, SPPINDEX treatment can initially attenuate the invasion of neuroinflammatory triggers into the brain parenchyma caused by insertion-induced microhemorrhages or a compromised BBB. Furthermore, targeted delivery of the anti-inflammatory drug dexamethasone sodium phosphate (DEXSP) to the implant site via these nanoparticles can attenuate ongoing neuroinflammation, enhancing overall therapeutic efficacy. Weekly treatment with SPPINDEX for 8 weeks significantly improved the recording capabilities of IMEs compared to platelet-inspired nanoparticles alone (PIN), free dexamethasone sodium phosphate (Free DEXSP), and a diluent control trehalose buffer (TH), as assessed through extracellular single-unit recordings. Immunohistochemical analyses of neuron density, activated microglia/macrophage density, astrocyte density, and BBB permeability suggest that the improved neural recording performance may be attributed to reduced neuron degeneration, activated microglia and astrocytes at the implant interface caused by the decreased infiltration of blood-derived proteins that trigger neuroinflammation and the therapeutic effects from DEXSP. Overall, SPPINDEX treatment promotes an anti-inflammatory environment that improves neuronal density and enhances recording performance.

Polysaccharide-based hydrogels for atopic dermatitis management: A review

Atopic dermatitis (AD) is the most common form of eczema and the most burdensome skin disease globally, affecting nearly 223 million. A major AD predisposition is genetic susceptibility, affecting skin barrier integrity and cell-mediated immunity. Manifesting as red, dry, and itchy skin, basic treatment involves skin hydration with emollients. Despite their effectiveness, poor patient compliance remains a major drawback. In severe cases, medicated emollients are used, but carry risks, including skin thinning, and immunosuppression. Hence, hydrogels have emerged as a promising alternative for AD management based on their ability to improve skin hydration, attributed to their hydrophilicity and high water retention capacity. Moreover, researchers have loaded hydrogels with various compounds for AD management; they also hold the potential to reduce systemic side effects of commercial drugs by enhancing dermal retention. Hydrogels address the challenges of patient compliance based on their non-greasy texture and reduced application frequency. Their appeal also stems from their versatility, as they can be fabricated from varying polymers. Due to their abundance, this review focuses on polysaccharides including alginate, cellulose, chitosan, and hyaluronic acid, which are preferred for fabricating natural and modified natural hydrogels for AD. It also briefly explores hydrogel application methods and key AD models.

From Preformulative Design to In Vivo Tests: A Complex Path of Requisites and Studies for Nanoparticle Ocular Application. Part 1: Design, Characterization, and Preliminary In Vitro Studies

Ocular pathologies are widely diffused worldwide, and their effective treatment, combined with a high patient compliance, is sometimes challenging to achieve due to the barriers of the eye; in this context, the use of nanoparticles for topical ophthalmic application could represent a successful strategy. Aiming to develop nanoplatforms with potential clinical applications, great attention has to be paid to their features, in relation to the route of administration and to the pharmacopoeial requirements. This review (part 1) thus embraces the preliminary steps of nanoparticle development and characterization. At the beginning, the main barriers of the eye and the different administration routes are resumed, followed by a general description of the advantages of the employment of nanoparticles for ocular topical administration. Subsequently, the preformulative steps are discussed, deepening the choice of raw materials and determining the quantitative composition. Then, a detailed report of the physicochemical and technological characterization of nanoparticles is presented, analyzing the most relevant tests that should be performed on nanoparticles to verify their properties and the requisites (both mandatory and suggested) demanded by regulatory agencies. In conclusion, some preliminary noncellular in vitro evaluation methods are described. Studies from in vitro cellular assays to in vivo tests will be discussed in a separate (part 2) review paper. Hence, this overview aims to offer a comprehensive tool to guide researchers in the choice of the most relevant studies to develop a nanoplatform for ophthalmic drug administration.

Ferric ions crosslinked hyaluronic acid beads: potentials for drug delivery use

INTRODUCTION AND PURPOSE

Despite the attractive properties of hyaluronic acid (HA), The preparation of HA beads is still challenging. This article reports the preparation of pH-sensitive gel HA beads. The ionic gelation method was used to prepare the HA gel beads using ferric ions. This cross-linking type is based on forming coordination bonds, which enhance the mechanical properties of the prepared beads.

METHODS

The developed beads were characterized using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) examined the bead's morphology. Furthermore, the potential of HA gel beads as an oral drug delivery system was investigated using metformin as a hydrophilic model drug. The entrapment efficiency and in vitro, release, and release kinetics were evaluated. The crosslinking density and HA concentration effect on drug release and bead swelling capacity under pH 1.2 and 7.4 were also investigated.

RESULTS

The entrapment efficiency of metformin in HA beads was found to be 79.56 ± 3.89%. FTIR analysis indicated the ionic interaction between ferric ions and the carboxylic groups on the HA molecule. At the same time, there was no substantial interaction between metformin and the polymeric bead. Morphological evaluation and DSC analysis suggested the successful incorporation of metformin within the beads. The in vitro drug release evaluation showed pH-dependent extended release where the release kinetics followed the first-order mathematical model.

CONCLUSIONS

This study provides a value-added formulation with the potential for drug delivery use, which can be further investigated for biomedical applications.

Chemotherapeutic Drug Delivery Nanoplatform Development: From Physicochemical to Preclinical Evaluation

Through this study, the synergistic behavior of small-molecular-weight, amphiphilic surfactant molecules and the triblock copolymer Pluronic 188 was extensively evaluated based on their ability to formulate nanocarriers with novel properties for the delivery of class II and IV (biopharmaceutical classification system) chemotherapeutic compounds. The combination of four different surfactants at multiple weight ratios and twelve initially formulated nanosystems resulted in four hybrid delivery platforms, which were further studied in terms of multiple physicochemical characteristics, as well as their stability in protein-rich media (fetal bovine serum/phosphate-buffer saline). Finally, we obtained a single final nanoformulation that exhibited a high loading capacity (%EE ≥ 75%) and a sustained drug release profile under physiological conditions (model drug methotrexate), without altering the original physicochemical characteristics of the carrier. With a mean hydrodynamic radius (Rh) of less than 70 nm, a polydispersity index of 0.219, and no protein complexation, the system is a suitable candidate for in vivo, intravenous, and/or intramuscular administration. The cytotoxicity and genotoxicity of both loaded and unloaded carriers were evaluated through the examination of the upregulation or downregulation of apoptosis-related pathways. Multiple conventional 2D and 3D spheroidal conformations were used for these assessments, including HEK293, HCT-116, and MCF-7 cell lines, the results of which stressed the safety and biocompatibility of the empty nanocarrier. Additionally, experiments on Caenorhabditis elegans were conducted to evaluate the system's in vivo toxicity, focusing on developmental stages, egg-laying behavior, and locomotion. Nanosystems studied in terms of chemotherapeutic encapsulation have mostly focused on the physiochemical aspect of the development of such novel delivery platforms, with only few exceptions proceeding step-by-step from cellular 2D to 3D to in vivo experimentation. The present study offers a holistic view of the behavior of such a novel system, advancing our understanding of the capabilities of polymeric/surfactant-based nanodelivery platforms.

Bacterial cellulose films for L-asparaginase delivery to melanoma cells

L-asparaginase (L-ASNase) is an enzyme that catalyzes the hydrolysis of L-asparagine to L-aspartic acid and ammonia and is used to treat acute lymphoblastic leukemia. It is also toxic to the cells of some solid tumors, including melanoma cells. Immobilization of this enzyme can improve its activity against melanoma tumor cells. In this work, the properties of bacterial cellulose (BC) and feasibility of BC films as a new carrier for immobilized L-ASNase were investigated. Different values of growth time were used to obtain BC films with different thicknesses and porosities, which determine the water content and the ability to adsorb and release L-ASNase. Fourier transform infrared spectroscopy confirmed the adsorption of the enzyme on the BC films. The total activity of adsorbed L-ASNase and its release were investigated for films grown for 48, 72 or 96 h. BC films grown for 96 h showed the most pronounced release as described by zero-order and Korsmayer-Peppas models. The release was characterized by controlled diffusion where the drug was released at a constant rate. BC films with immobilized L-ASNase could induce cytotoxicity in A875 human melanoma cells. With further development, immobilization of L-ASNase on BC may become a potent strategy for anticancer drug delivery to superficial tumors.

An in vitro study for reducing the cytotoxicity and dose dumping risk of remdesivir via entrapment in nanostructured lipid carriers

The aim of this study was to synthesize and evaluate nanostructured lipid carriers (NLCs) loaded with Remdesivir (RDV) to control its side effects in COVID-19 patients. Due to the low solubility and short half-life of RDV in the blood, an injectable formulation was prepared using sulphobutylether-beta-cyclodextrin. However, it can accumulate in the kidney and cause renal impairment. NLCs improve the parenteral delivery of hydrophobic drugs such as RDV by increasing drug solubility and bioavailability. For the synthesis of RDV-NLCs, the aqueous phase containing Tween 80 was injected into the lipid phase under rapid stirring and was sonicated. The experimental conditions were optimized using Box-Behnken design and Design Expert software. The optimum formulation contained a total lipid of 2.13%, a total surfactant of 1%, and a hot bath time of 71 min. The optimum formulation showed particle size, polydispersity index, zeta potential, and entrapment efficiency values of 151.0 ± 1.7 nm (from 149.1 to 152.1), 0.4 ± 0.1 (from 0.3 to 0.5), -43.8 ± 1.2 mV (from -42.4 to -44.7), and 81.34 ± 1.57% (from 79.52 to 82.33%), respectively. RDV-NLCs showed acceptable stability for 30 days at 25 ℃ and were compatible with commonly used intravenous infusion fluids for 48 h. FE-SEM images of RDV-NLC showed spherical particles with a mean diameter of 207 nm. The NLC-RDV formulation showed a sustained release of RDV with a low risk of dose-dumping, minimizing potential side effects. In addition, RDV in the form of RDV-NLC causes less cytotoxicity to healthy normal kidney cells, which is expected to reduce renal impairment in COVID-19 patients.

Dual-Functionalized Mesoporous Silica Nanoparticles for Celecoxib Delivery: Amine Grafting and Imidazolyl PEI Gatekeepers for Enhanced Loading and Controlled Release with Reduced Toxicity

The development of targeted drug delivery systems has been a pivotal area in nanomedicine, addressing challenges like low drug loading capacity, uncontrolled release, and systemic toxicity. This study aims to develop and evaluate dual-functionalized mesoporous silica nanoparticles (MSN) for targeted delivery of celecoxib, enhancing drug loading, achieving controlled release, and reducing systemic toxicity through amine grafting and imidazolyl polyethyleneimine (PEI) gatekeepers. MSN were synthesized using the sol-gel method and functionalized with (3-aminopropyl) triethoxysilane (APTES) to create amine-grafted MSN (MSN-NH2). Celecoxib was loaded into MSN-NH2, followed by conjugation of imidazole-functionalized PEI (IP) gatekeepers synthesized via carbodiimide coupling. Characterization was conducted using Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR). Drug loading capacity, entrapment efficiency, and in vitro drug release at pH 5.5 and 7.4 were evaluated. Cytotoxicity was assessed using the MTT assay on RAW 264.7 macrophages. The synthesized IP was confirmed by FTIR and 1H-NMR. Amine-grafted MSN demonstrated a celecoxib loading capacity of 12.91 ± 2.02%, 2.1 times higher than non-functionalized MSN. In vitro release studies showed pH-responsive behavior with significantly higher celecoxib release from MSN-NH2-celecoxib-IP at pH 5.5 compared to pH 7.4, achieving a 33% increase in release rate within 2 h. Cytotoxicity tests indicated significantly higher cell viability for IP-treated cells compared to PEI-treated cells, confirming reduced toxicity. The dual-functionalization of MSN with amine grafting and imidazolyl PEI gatekeepers enhances celecoxib loading and provides controlled pH-responsive drug release while reducing systemic toxicity. These findings highlight the potential of this advanced drug delivery system for targeted anti-inflammatory and anticancer therapies.

Development and Evaluation of Docetaxel-Loaded Nanostructured Lipid Carriers for Skin Cancer Therapy

This study focuses on the design, characterization, and optimization of nanostructured lipid carriers (NLCs) loaded with docetaxel for the treatment of skin cancer. Employing a systematic formulation development process guided by Design of Experiments (DoE) principles, key parameters such as particle size, polydispersity index (PDI), zeta potential, and entrapment efficiency were optimized to ensure the stability and drug-loading efficacy of the NLCs. Combined XRD and cryo-TEM analysis were employed for NLC nanostructure evaluation, confirming the formation of well-defined nanostructures. In vitro kinetics studies demonstrated controlled and sustained docetaxel release over 48 h, emphasizing the potential for prolonged therapeutic effects. Cytotoxicity assays on human umbilical vein endothelial cells (HUVEC) and SK-MEL-24 melanoma cell line revealed enhanced efficacy against cancer cells, with significant selective cytotoxicity and minimal impact on normal cells. This multidimensional approach, encompassing formulation optimization and comprehensive characterization, positions the docetaxel-loaded NLCs as promising candidates for advanced skin cancer therapy. The findings underscore the potential translational impact of these nanocarriers, paving the way for future preclinical investigations and clinical applications in skin cancer treatment.

Nanofibrous Microspheres: A Biomimetic Platform for Bone Tissue Regeneration

Bone, a fundamental constituent of the human body, is a vital scaffold for support, protection, and locomotion, underscoring its pivotal role in maintaining skeletal integrity and overall functionality. However, factors such as trauma, disease, or aging can compromise bone structure, necessitating effective strategies for regeneration. Traditional approaches often lack biomimetic environments conducive to efficient tissue repair. Nanofibrous microspheres (NFMS) present a promising biomimetic platform for bone regeneration by mimicking the native extracellular matrix architecture. Through optimized fabrication techniques and the incorporation of active biomolecular components, NFMS can precisely replicate the nanostructure and biochemical cues essential for osteogenesis promotion. Furthermore, NFMS exhibit versatile properties, including tunable morphology, mechanical strength, and controlled release kinetics, augmenting their suitability for tailored bone tissue engineering applications. NFMS enhance cell recruitment, attachment, and proliferation, while promoting osteogenic differentiation and mineralization, thereby accelerating bone healing. This review highlights the pivotal role of NFMS in bone tissue engineering, elucidating their design principles and key attributes. By examining recent preclinical applications, we assess their current clinical status and discuss critical considerations for potential clinical translation. This review offers crucial insights for researchers at the intersection of biomaterials and tissue engineering, highlighting developments in this expanding field.

Design of Experiment (DoE) Approach for Developing Inhalable PLGA Microparticles Loaded with Clofazimine for Tuberculosis Treatment

Tuberculosis (TB) is an airborne bacterial infection caused by Mycobacterium tuberculosis (M. tb), resulting in approximately 1.3 million deaths in 2022 worldwide. Oral therapy with anti-TB drugs often fails to achieve therapeutic concentrations at the primary infection site (lungs). In this study, we developed a dry powder inhalable formulation (DPI) of clofazimine (CFZ) to provide localized drug delivery and minimize systemic adverse effects. Poly (lactic acid-co-glycolic acid) (PLGA) microparticles (MPs) containing CFZ were developed through a single emulsion solvent evaporation technique. Clofazimine microparticles (CFZ MPs) displayed entrapment efficiency and drug loading of 66.40 ± 2.22 %w/w and 33.06 ± 1.45 µg/mg, respectively. To facilitate pulmonary administration, MPs suspension was spray-dried to yield a dry powder formulation (CFZ SD MPs). Spray drying had no influence on particle size (~1 µm), zeta potential (-31.42 mV), and entrapment efficiency. Solid state analysis (PXRD and DSC) of CFZ SD MPs studies demonstrated encapsulation of the drug in the polymer. The drug release studies showed a sustained drug release. The optimized formulation exhibited excellent aerosolization properties, suggesting effective deposition in the deeper lung region. The in vitro antibacterial studies against H37Ra revealed improved (eight-fold) efficacy of spray-dried formulation in comparison to free drug. Hence, clofazimine dry powder formulation presents immense potential for the treatment of tuberculosis with localized pulmonary delivery and improved patient compliance.

Selective Delivery of Clindamycin Using a Combination of Bacterially Sensitive Microparticle and Separable Effervescent Microarray Patch on Bacteria Causing Diabetic Foot Infection

INTRODUCTION

Diabetic foot infection (DFI) is one of the complications of diabetes mellitus. Clindamycin (CLY) is one of the antibiotics recommended to treat DFI, but CLY given orally and intravenously still causes many side effects.

METHODS

In this study, we encapsulated CLY in a bacteria sensitive microparticle system (MP-CLY) using polycaprolactone (PCL) polymer. MP-CLY was then delivered in a separable effervescent microarray patch (MP-CLY-SEMAP), which has the ability to separate between the needle layer and separable layer due to the formation of air bubbles when interacting with interstitial fluid in the skin.

RESULT

The characterization results of MP-CLY proved that CLY was encapsulated in large amounts as the amount of PCL polymer used increased, and there was no change in the chemical structure of CLY. In vitro release test results showed increased CLY release in media cultured with Staphylococcus aureus bacteria and showed controlled release. The characterization results of MPCLY-SEMAP showed that the developed formula has optimal mechanical and penetration capabilities and can separate in 56 ± 5.099 s. An ex vivo dermatokinetic test on a bacterially infected skin model showed an improvement of CLY dermatokinetic profile from MP-CLY SEMAP and a decrease in bacterial viability by 99.99%.

CONCLUSION

This research offers proof of concept demonstrating the improved dermatokinetic profile of CLY encapsulated in a bacteria sensitive MP form and delivered via MP-CLY-SEMAP. The results of this research can be developed for future research by testing MP-CLY-SEMAP in vivo in appropriate animal models.

Biodegradable Long-Acting Injectables: Platform Technology and Industrial Challenges

Long-acting injectables have been used to benefit patients with chronic diseases. So far, several biodegradable long-acting platform technologies including drug-loaded polymeric microparticles, implants (preformed and in situ forming), oil-based solutions, and aqueous suspension have been established. In this chapter, we summarize all the marketed technology platforms and discuss their challenges regarding development including but not limited to controlling drug release, particle size, stability, sterilization, scale-up manufacturing, etc. Finally, we discuss important criteria to consider for the successful development of long-acting injectables.

Synthesis and Characterization of Baicalein-loaded Aquasomes: An In vitro and In silico Perspective for Diabetes Mellitus

BACKGROUND

Millions of individuals worldwide suffer from metabolic abnormalities induced by diabetes. Baicalein, a flavonoid, has shown several properties in various treatments with potential properties, including anti-inflammatory, antioxidant, and anti-diabetic properties. Practically, its application is hindered due to low solubility in aqueous media. Overcoming this challenge, aquasomes can offer an effective approach for delivering drugs and bioactive molecules to target various diseases.

OBJECTIVE

The study aimed to develop and evaluate baicalein-loaded aquasomes for improving solubility and comparing their antidiabetic properties to acarbose through in silico docking.

METHODS

Baicalein-loaded aquasomes were prepared through a three-step process: core preparation, lactose coating, and drug loading. The evaluation included assessing particle size, drug-excipient interactions, drug entrapment efficiency, loading capacity, in vitro drug release, and the kinetics of drug release. In silico docking and in vitro α-amylase inhibition activity was evaluated to assess the anti-diabetic potential of baicalein.

RESULTS

The baicalein-loaded aquasomes were spherical with sizes ranging from 300-400 nm. FTIR analysis indicated no interaction between the components. The formulation exhibited drug entrapment efficiency of 94.04±0 4.01% and drug loading of 17.60 ± 01.03%. Drug release study showed sustained and complete (97.30 ± 02.06%) release, following first-order kinetics. Docking analysis revealed comparable binding affinity to acarbose, while the α-amylase inhibition assay showed greater inhibition potential of the aquasomes compared to the baicalein solution.

CONCLUSION

Aquasomes offer an alternative approach to conventional delivery methods. The selfassembling characteristics of aquasomes greatly simplify their preparation process, adding to their appeal as a drug delivery system.

A Review on the Recent Advancements and Artificial Intelligence in Tablet Technology

BACKGROUND

Tablet formulation could be revolutionized by the integration of modern technology and established pharmaceutical sciences. The pharmaceutical sector can develop tablet formulations that are not only more efficient and stable but also patient-friendly by utilizing artificial intelligence (AI), machine learning (ML), and materials science.

OBJECTIVES

The primary objective of this review is to explore the advancements in tablet technology, focusing on the integration of modern technologies like artificial intelligence (AI), machine learning (ML), and materials science to enhance the efficiency, cost-effectiveness, and quality of tablet formulation processes.

METHODS

This review delves into the utilization of AI and ML techniques within pharmaceutical research and development. The review also discusses various ML methodologies employed, including artificial neural networks, an ensemble of regression trees, support vector machines, and multivariate data analysis techniques.

RESULTS

Recent studies showcased in this review demonstrate the feasibility and effectiveness of ML approaches in pharmaceutical research. The application of AI and ML in pharmaceutical research has shown promising results, offering a potential avenue for significant improvements in the product development process.

CONCLUSION

The integration of nanotechnology, AI, ML, and materials science with traditional pharmaceutical sciences presents a remarkable opportunity for enhancing tablet formulation processes. This review collectively underscores the transformative role that AI and ML can play in advancing pharmaceutical research and development, ultimately leading to more efficient, reliable and patient-centric tablet formulations.

Nattokinase Encapsulated Nanomedicine for Targeted Thrombolysis: Development, Improved in Vivo Thrombolytic Effects, and Ultrasound/Photoacoustic Imaging

Nattokinase (NK), a potent thrombolytic enzyme that dissolves blood clots, is highly used in the treatment of cardiovascular disorders. However, its effective delivery remains demanding because of stability and bioavailability problems owing to its high molecular weight and proteineous nature. In this research, we have developed novel NK-loaded nontargeted liposomes (NK-LS) and targeted liposomes (RGD-NK-LS and AM-NK-LS) by the reverse phase evaporation method. The physiochemical characterizations (particle size, polydispersity index, zeta potential, and morphology) were performed by a Zetasizer, SEM, TEM, and AFM. The Bradford assay and XPS analysis confirmed the successful surface conjugation of the targeting ligands. Platelet interaction studies by CLSM, photon imager optima, and flow cytometry showed significantly higher (P < 0.05) platelet binding affinity of targeted liposomes. In vitro evaluations were performed using human blood and a fibrinolysis study by CLSM imaging demonstrating the potent antithrombotic efficacy of AM-NK-LS. Furthermore, bleeding and clotting time studies revealed that the targeted liposomes were free from any bleeding complications. Moreover, the in vivo FeCl3 model on Sprague-Dawley (SD) rats using a Doppler flow meter and ultrasound/photoacoustic imaging indicated the increased % thrombolysis and potent affinity of targeted liposomes toward the thrombus site. Additionally, in vitro hemocompatibility and histopathology studies demonstrated the safety and biocompatibility of the nanoformulations.

Long-Acting Injectable Antipsychotics-A Review on Formulation and In Vitro Dissolution

Long-acting injectable (LAI) neuroleptics constitute an effective therapeutical alternative for individuals suffering from persistent mental illness. These injectable pharmaceuticals help patients manage their condition better and improve long-term outcomes by preventing relapses and improving compliance. This review aims to analyse the current formulation aspects of LAI neuroleptics, with particular emphasis on analysis of drug release profiles as a critical test to guarantee drug quality and relevant therapeutical activity. While there is no officially approved procedure for depot parenteral drug formulations, various dissolution tests which were developed by LAI manufacturers are described. In vitro dissolution tests also possess a critical function in the estimation of the in vivo performance of a drug formulation. For that reason, thorough inspection of the in vitro-in vivo correlation (IVIVC) is also discussed.

Development of long-acting injectable suspensions by continuous antisolvent crystallization: An integrated bottom-up process

Our present work elucidated the operational feasibility of direct generation and stabilization of long-acting injectable (LAI) suspensions of a practically insoluble drug, itraconazole (ITZ), by combining continuous liquid antisolvent crystallization with downstream processing (i.e., centrifugal filtration and reconstitution). A novel microchannel reactor-based bottom-up crystallization setup was assembled and optimized for the continuous production of micro-suspension. Based upon the solvent screening and solubility study, N-methyl pyrrolidone (NMP) was selected as the optimal solvent and an impinging jet Y-shaped microchannel reactor (MCR) was selected as the fluidic device to provide a reproducible homogenous mixing environment. Operating parameters such as solvent to antisolvent ratio (S/AS), total jet liquid flow rates (TFRs), ITZ feed solution concentration and the maturation time in spiral tubing were tailored to 1:9 v/v, 50 mL/min, 10 g/100 g solution, and 96 h, respectively. Vitamin E TPGS (0.5% w/w) was found to be the most suitable excipient to stabilize ITZ particles amongst 14 commonly used stabilizers screened. The effect of scaling up from 25 mL to 15 L was evaluated effectively with in situ monitoring of particle size distribution (PSD) and solid-state form. Thereafter, the suspension was subjected to centrifugal filtration to remove excess solvent and increase ITZ solid fraction. As an alternative, an even more concentrated wet pellet was reconstituted with an aqueous solution of 0.5% w/w Vitamin E TPGS as resuspending agent. The ITZ LAI suspension (of 300 mg/mL solid concentration) has the optimal PSD with a D10 of 1.1 ± 0.3 µm, a D50 of 3.53 ± 0.4 µm and a D90 of 6.5 ± 0.8 µm, corroborated by scanning electron microscopy (SEM), as remained stable after 548 days of storage at 25 °C. Finally, in vitro release methods using Dialyzer, dialysis membrane sac were investigated for evaluation of dissolution of ITZ LAI suspensions. The framework presented in this manuscript provides a useful guidance for development of LAI suspensions by an integrated bottom-up approach using ITZ as model API.

Enhancement of Liver Targetability through Statistical Optimization and Surface Modification of Biodegradable Nanocapsules Loaded with Lamivudine

The intention of the current work was to develop and optimize the formulation of biodegradable polymeric nanocapsules for lamivudine (LMV) in order to obtain desired physical characteristics so as to have improved liver targetability. Nanocapsules were prepared in this study as aqueous-core nanocapsules (ACNs) with poly(lactide-co-glycolide) using a modified multiple emulsion technique. LMV was taken as a model drug to investigate the potential of ACNs developed in this work in achieving the liver targetability. Three formulations factors were chosen and 33 factorial design was adopted. The selected formulation factors were optimized statistically so as to have the anticipated characteristics of the ACNs viz. maximum entrapment efficiency, minimum particle size, and less drug release rate constant. The optimized LMV-ACNs were found to have 71.54 ± 1.93% of entrapment efficiency and 288.36 ± 2.53 nm of particle size with zeta potential of -24.7 ± 1.2 mV and 0.095 ± 0.006 h-1 of release rate constant. This optimized formulation was subjected to surface modification by treating with sodium lauryl sulphate (SLS), which increased the zeta potential to a maximum of -41.6 ± 1.3 mV at a 6 mM concentration of SLS. The results of in vivo pharmacokinetics from blood and liver tissues indicated that hepatic bioavailability of LMV was increased from 13.78 ± 3.48 μg/mL ∗ h for LMV solution to 32.94 ± 5.12 μg/mL ∗ h for the optimized LMV-ACNs and to 54.91 ± 6.68 μg/mL ∗ h for the surface-modified LMV-ACNs.

Fused Deposition Modeling Printed PLA/Nano β-TCP Composite Bone Tissue Engineering Scaffolds for Promoting Osteogenic Induction Function

Purpose

Large bone defects caused by congenital defects, infections, degenerative diseases, trauma, and tumors often require personalized shapes and rapid reconstruction of the bone tissue. Three-dimensional (3D)-printed bone tissue engineering scaffolds exhibit promising application potential. Fused deposition modeling (FDM) technology can flexibly select and prepare printed biomaterials and design and fabricate bionic microstructures to promote personalized large bone defect repair. FDM-3D printing technology was used to prepare polylactic acid (PLA)/nano β-tricalcium phosphate (TCP) composite bone tissue engineering scaffolds in this study. The ability of the bone-tissue-engineered scaffold to repair bone defects was evaluated in vivo and in vitro.

Methods

PLA/nano-TCP composite bone tissue engineering scaffolds were prepared using FDM-3D printing technology. The characterization data of the scaffolds were obtained using relevant detection methods. The physical and chemical properties, biocompatibility, and in vitro osteogenic capacity of the scaffolds were investigated, and their bone repair capacity was evaluated using an in vivo animal model of rabbit femur bone defects.

Results

The FDM-printed PLA/nano β-TCP composite scaffolds exhibited good personalized porosity and shape, and their osteogenic ability, biocompatibility, and bone repair ability in vivo were superior to those of pure PLA. The merits of biodegradable PLA and bioactive nano β-TCP ceramics were combined to improve the overall biological performance of the composites.

Conclusion

The FDM-printed PLA/nano-β-TCP composite scaffold with a ratio of 7:3 exhibited good personalized porosity and shape, as well as good osteogenic ability, biocompatibility, and bone repair ability. This study provides a promising strategy for treating large bone defects.

Mucoadhesive Alginate/Pectin Films Crosslinked by Calcium Carbonate as Carriers of a Model Antifungal Drug-Posaconazole

The mucosal membrane of the oral cavity, due to its unique structure and availability, constitutes an appropriate site for the delivery of drugs, both with local and systemic effects. Mucoadhesive buccal films are drug dosage forms that due to their convenience of application, flexibility and size, are characterized by patients' compliance. Sodium alginate and pectin are natural polymers from the polysaccharides group, with mucoadhesive properties, that are widely applied to obtain buccal films. However, their hydrophilic nature and poor water resistance limit their application in sustained drug release formulations. Hence, the aim of this investigation was to design alginate/pectin buccal films by a one-step crosslinking technique-with the application of calcium carbonate. This technique was applied to prepare crosslinked alginate and alginate/pectin mucoadhesive films with a model antifungal drug-posaconazole. The obtained formulations were evaluated for the impact of crosslinking and pectin's presence on their pharmaceutical, mucoadhesive, mechanical and physicochemical properties. Additionally, the antifungal activity of the prepared films against Candida spp. was evaluated. It was shown that pectin's presence in the formulations improved flexibility, mucoadhesion and antifungal activity. The crosslinking process reduced mucoadhesiveness and antifungal activity but significantly enhanced the mechanical properties and stability and enabled prolonged drug release.

Revisiting the in-vitro and in-vivo considerations for in-silico modelling of complex injectable drug products

Complex injectable drug products (CIDPs) have often been developed to modulate the pharmacokinetics along with efficacy for therapeutic agents used for remediation of chronic disorders. The effective development of CIDPs has exhibited complex kinetics associated with multiphasic drug release from the prepared formulations. Consequently, predictability of pharmacokinetic modelling for such CIDPs has been difficult and there is need for advanced complex computational models for the establishment of accurate prediction models for in-vitro-in-vivo correlation (IVIVC). The computational modelling aims at supplementing the existing knowledge with mathematical equations to develop formulation strategies for generation of predictable and discriminatory IVIVC. Such an approach would help in reduction of the burden of effect of hidden factors on preclinical to clinical translations. Computational tools like physiologically based pharmacokinetics (PBPK) modelling have combined physicochemical and physiological properties along with IVIVC characteristics of clinically used formulations. Such techniques have helped in prediction and understanding of variability in pharmacodynamic parameters of potential generic products to clinically used formulations like Doxil®, Ambisome®, Abraxane® in healthy and diseased population using mathematical equations. The current review highlights the important formulation characteristics, in-vitro, preclinical in-vivo aspects which need to be considered while developing a stimulatory predictive PBPK model in establishment of an IVIVC and in-vitro-in-vivo relationship (IVIVR).

The recent insight in the release of anticancer drug loaded into PLGA microspheres

Cancer is a series of diseases leading to a high rate of death worldwide. Microspheres display specific characteristics that make them appropriate for a variety of biomedical purposes such as cancer therapy. Newly, microspheres have the potentials to be used as controlled drug release carriers. Recently, PLGA-based microspheres have attracted exceptional attention relating to effective drug delivery systems (DDS) because of their distinctive properties for a simple preparation, biodegradability, and high capability of drug loading which might be increased drug delivery. In this line, the mechanisms of controlled drug release and parameters that influence the release features of loaded agents from PLGA-based microspheres should be mentioned. The current review is focused on the new development of the release features of anticancer drugs, which are loaded into PLGA-based microspheres. Consequently, future perspective and challenges of anticancer drug release from PLGA-based microspheres are mentioned concisely.

Current State and Opportunities with Long-acting Injectables: Industry Perspectives from the Innovation and Quality Consortium "Long-Acting Injectables" Working Group

Long-acting injectable (LAI) formulations can provide several advantages over the more traditional oral formulation as drug product opportunities. LAI formulations can achieve sustained drug release for extended periods of time, which results in less frequent dosing requirements leading to higher patient adherence and more optimal therapeutic outcomes. This review article will provide an industry perspective on the development and associated challenges of long-acting injectable formulations. The LAIs described herein include polymer-based formulations, oil-based formulations, and crystalline drug suspensions. The review discusses manufacturing processes, including quality controls, considerations of the Active Pharmaceutical Ingredient (API), biopharmaceutical properties and clinical requirements pertaining to LAI technology selection, and characterization of LAIs through in vitro, in vivo and in silico approaches. Lastly, the article includes a discussion around the current lack of suitable compendial and biorelevant in vitro models for the evaluation of LAIs and its subsequent impact on LAI product development and approval.

Hyaluronic acid-conjugated liposomes loaded with dexamethasone: a promising approach for the treatment of inflammatory diseases

Dexamethasone is a well-known anti-inflammatory drug readily used to treat many lung diseases. However, its side effects and poor lower airway deposition and retention are significant limitations to its usage. In this work, we developed lipid nanoparticulate platforms loaded with dexamethasone and evaluated their behavior in inflammatory lung models in vitro and in vivo. Dexamethasone-loaded liposomes with an average diameter below 150 nm were obtained using a solvent injection method. Three different formulations were produced with a distinct surface coating (polyethylene glycol, hyaluronic acid, or a mixture of both) as innovative strategies to cross the pulmonary mucus layer and/or target CD44 expressed on alveolar proinflammatory macrophages. Interestingly, while electron paramagnetic spectroscopy showed that surface modifications did not induce any molecular changes in the liposomal membrane, drug loading analysis revealed that adding the hyaluronic acid in the bilayer led to a decrease of dexamethasone loading (from 3.0 to 1.7w/w%). In vitro experiments on LPS-activated macrophages demonstrated that the encapsulation of dexamethasone in liposomes, particularly in HA-bearing ones, improved its anti-inflammatory efficacy compared to the free drug. Subsequently, in vivo data revealed that while intratracheal administration of free dexamethasone led to an important inter-animals variation of efficacy, dexamethasone-loaded liposomes showed an improved consistency within the results. Our data indicate that encapsulating dexamethasone into lipid nanoparticles is a potent strategy to improve its efficacy after lung delivery.

Multipolymer microsphere delivery of SARS-CoV-2 antigens

Effective antigen delivery facilitates antiviral vaccine success defined by effective immune protective responses against viral exposures. To improve severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigen delivery, a controlled biodegradable, stable, biocompatible, and nontoxic polymeric microsphere system was developed for chemically inactivated viral proteins. SARS-CoV-2 proteins encapsulated in polymeric microspheres induced robust antiviral immunity. The viral antigen-loaded microsphere system can preclude the need for repeat administrations, highlighting its potential as an effective vaccine. STATEMENT OF SIGNIFICANCE: Successful SARS-CoV-2 vaccines were developed and quickly approved by the US Food and Drug Administration (FDA). However, each of the vaccines requires boosting as new variants arise. We posit that injectable biodegradable polymers represent a means for the sustained release of emerging viral antigens. The approach offers a means to reduce immunization frequency by predicting viral genomic variability. This strategy could lead to longer-lasting antiviral protective immunity. The current proof-of-concept multipolymer study for SARS-CoV-2 achieve these metrics.

Development of a porous layer-by-layer microsphere with branched aliphatic hydrocarbon porogens

Porous polymer microspheres are employed in biotherapeutics, tissue engineering, and regenerative medicine. Porosity dictates cargo carriage and release that are aligned with the polymer physicochemical properties. These include material tuning, biodegradation, and cargo encapsulation. How uniformity of pore size affects therapeutic delivery remains an area of active investigation. Herein, we characterize six branched aliphatic hydrocarbon-based porogen(s) produced to create pores in single and multilayered microspheres. The porogens are composed of biocompatible polycaprolactone, poly(lactic-co-glycolic acid), and polylactic acid polymers within porous multilayered microspheres. These serve as controlled effective drug and vaccine delivery platforms.

Some things old, new and borrowed: Delivery of dabrafenib and vemurafenib to melanoma cells via self-assembled nanomicelles based on an amphiphilic dendrimer

Two clinically approved anticancer drugs targeting BRAF in melanoma patients - dabrafenib (DAB) and vemurafenib (VEM) - have been successfully encapsulated into nanomicelles formed upon self-assembly of an amphiphilic dendrimer AD based on two C₁₈ aliphatic chains and a G2 PAMAM head. The process resulted in the formation of well-defined (∼10 nm) core-shell nanomicelles (NMs) with excellent encapsulation efficiency (∼70% for DAB and ∼60% for VEM) and good drug loading capacity (∼27% and ∼24% for DAB and VEM, respectively). Dynamic light scattering (DLS), transmission electron microscopy (TEM), small-angle x-ray scattering (SAXS), nuclear magnetic resonance (NMR), isothermal titration calorimetry (ITC), and molecular simulation (MS) experiments were used, respectively, to determine the size and structure of the empty and drug-loaded nanomicelles (DLNMs), along with the interactions between the NMs and their cargoes. The in vitro release data revealed profiles governed by Fickian diffusion; moreover, for both anticancer molecules, an acidic environment (pH = 5.0) facilitated drug release with respect to physiological pH conditions (pH = 7.4). Finally, both DAB- and VEM-loaded NMs elicited enhanced response with respect to free drug treatments in 4 different melanoma cell lines.

Efficient delivery of abciximab using mesoporous silica nanoparticles: In-vitro assessment for targeted and improved antithrombotic activity

Abciximab (ABX) is a chimeric monoclonal antibody reported for antithrombotic activity but their delivery remains challenging due to its poor stability in a biological system. The purpose of this research was to deliver ABX on the target efficiently using mesoporous silica nanoparticles (MSN). ABX coated mesoporous silica nanoparticles (MSN-ABX) were formulated and analyzed for particle size, shape, zeta-potential, surface morphology and surface chemistry. XPS analysis confirmed the presence of ABX on the surface of amino functionalized mesoporous silica nanoparticles (MSN-NH₂). The degree of ABX attachment was 67.53 ± 5.81 % which was demonstrated by the Bradford assay. Furthermore, the targeting efficiency of the targeted nanoparticles has been evaluated by capturing the fluorescent images in-vitro which showed the significant accumulation of the ABX coated nanoparticles towards activated platelets. The significant (P < 0.05) increase in affinity of DiD dye loaded nanoparticles towards the activated platelets was confirmed by using an in-vitro imaging through photon imager optima. The hemolysis study of the nanoparticle formulations revealed that they were non-hemolytic for healthy human blood. The in-vitro antithrombotic effects of MSN-ABX were observed by blood clot assay which revealed its superior antithrombotic activity over clinical injection of ABX and could be a promising carrier for improved ABX targeted delivery.

Microfluidic Systems For Manufacturing of Microparticle-Based Drug-Delivery Systems: Design, Construction, and Operation

Particles synthesized from biodegradable polymers hold great potential as controlled drug delivery systems. Continuous flow platforms based on microfluidics offer attractive advantages over conventional batch-emulsification techniques for the scalable fabrication of drug-loaded particles with controlled physicochemical properties. However, widespread utilization of microfluidic technologies for the manufacturing of drug-loaded particles has been hindered largely by the lack of practical guidelines toward cost-effective development and reliable operation of microfluidic systems. Here, we present a framework for rational design and construction of microfluidic systems using commercially available components for high-throughput production of uniform biodegradable particles encapsulating drugs. We also demonstrate successful implementation of this framework to devise a robust microfluidic system that is capable of producing drug-carrying particles with desired characteristics. The guidelines provided in this study will likely help broaden the applicability of microfluidic technologies for the synthesis of high-quality, drug-loaded biodegradable particles.

Tissue engineered drug delivery vehicles: Methods to monitor and regulate the release behavior

Tissue engineering is a rapidly evolving, multidisciplinary field that aims at generating or regenerating 3D functional tissues for in vitro disease modeling and drug screening applications or for in vivo therapies. A variety of advanced biological and engineering methods are increasingly being used to further enhance and customize the functionality of tissue engineered scaffolds. To this end, tunable drug delivery and release mechanisms are incorporated into tissue engineering modalities to promote different therapeutic processes, thus, addressing challenges faced in the clinical applications. In this review, we elaborate the mechanisms and recent developments in different drug delivery vehicles, including the quantum dots, nano/micro particles, and molecular agents. Different loading strategies to incorporate the therapeutic reagents into the scaffolding structures are explored. Further, we discuss the main mechanisms to tune and monitor/quantify the release kinetics of embedded drugs from engineered scaffolds. We also survey the current trend of drug delivery using stimuli driven biopolymer scaffolds to enable precise spatiotemporal control of the release behavior. Recent advancements, challenges facing current scaffold-based drug delivery approaches, and areas of future research are discussed.

Preparation of stable enteric folic acid-loaded microfiber using the electrospinning method

Objectives

Folic acid is an essential vitamin, labile to hydrolysis in the acidic environment of the stomach with low water solubility and bioavailability. In order to solve these problems, enteric oral folic acid-loaded microfibers with a pH-sensitive polymer by electrospinning method were prepared.

Materials and Methods

Electrospinning was performed at different folic acid ratios and voltages. Fibers were evaluated in terms of mechanical strength, acidic resistance, and drug release. Additionally, DSC (Differential Scanning Calorimetry), FTIR (Fourier-transform infrared spectroscopy), and XRD (X-ray diffraction) analyses were performed on the optimal formulation.

Results

Drug ratio and voltage had a considerable effect on fibers' entrapment efficiency, acid resistance, and mechanical strength. Based on the obtained results, the optimum formulation containing 1.25% of the drug/polymer was prepared at 18 kV. The entrapment efficiency of the optimal sample was above 90% with an acid resistance of higher than 70%. The tensile test confirmed the high mechanical properties of the optimum microfiber. DSC and XRD tests indicated that folic acid was converted to an amorphous form in the fiber structure and the FTIR test confirmed the formation of a chemical bond between the drug and the polymer. The release of the drug from the optimal fiber was about 90% in 60 min.

Conclusion

In conclusion, the optimal formulation of folic acid with proper mechanical properties can be used as a candidate dosage form for further bioavailability investigations.