Pharmaceutics

To achieve their therapeutic effect on the brain, molecules need to pass the blood-brain-barrier (BBB). Many pharmacological treatments of neuropathologies encounter the BBB as a barrier, hindering their effective use. Pharmaceutical nanotechnology based on optimal physicochemical features and taking advantage of naturally occurring permeability mechanisms, nanocarriers such as liposomes offer an attractive alternative to allow drug delivery across the BBB. Liposomes are spherical bilayer lipid-based nanocapsules that can load hydrophilic molecules in their inner compartment and on their outer surface can be functionally modified by peptides, antibodies and polyethyleneglycol (PEG). When composed of cationic lipids, liposomes can serve as gene delivery devices, encapsulating and protecting genetic material from degradation and promoting nonviral cell transfection. In this study, we aimed to develop a liposomal formulation to encapsulate a plasmid harbouring brain-derived neurotrophic factor (BDNF) and infuse these liposomes via the peripheral bloodstream into the brain. To this end, liposomes were tagged with PEG, transferrin, and arginine and characterized regarding their physical properties, such as particle size, zeta-potential and polydispersity index (PDI). Moreover, we selected liposomes preparations for plasmid DNA (pDNA) encapsulation and checked for loading efficiency, in vitro cell uptake, and transfection. The preliminary results from this pilot study revealed that we were able to replicate the liposomes synthesis described in literature, achieving compatible size, charge, PDI, and loading efficiency. However, we could not properly determine whether the conjugation of the surface ligands transferrin and arginine to PEG worked and whether they were attached to the surface of the liposomes. Additionally, we were not able to see transfection in SH-SY5Y cells after 24 or 48 hours of incubation with the pDNA loaded liposomes. In conclusion, we synthesized liposomes encapsulation pBDNF, however, further research will be necessary to address the complete physicochemical characterization of the liposomes. Furthermore, preclinical studies will be helpful to verify transfection efficiency, cytotoxicity, and in the future, safe delivery of BDNF through the BBB.

SlpB from Levilactobacillus brevis offers a solution to stabilise liposome in gastrointestinal tract, and to target intestinal APCs in Peyers patches, rendering it a powerful tool for oral delivery of drugs, and to yield the benefits provided by oral delivery. However, the stability of SlpB-coated liposome (SlpB-LP) and its distribution in tissues were not characterized. In this study, we have demonstrated that SlpB-coating could improve the stability of liposome in gastrointestinal tract, and facilitate specific uptake of liposome into Peyers patches, but not intestinal, nor intestinal mucosa. Furthermore, we have shown that uptake of SlpB-LP into Peyers patches enhanced bioavailability of drugs, which have resulted in 427.65-fold increase in bioavailability and at least 2.41-fold decrease in retention of fluorophore in liver where drug metabolism takes places, to a degree which approximate control group. In conclusion, this study shows that SlpB could increase stability of liposome in gastrointestinal tract, increase specific uptake of liposome into Peyers patches, and improve bioavailability. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=196 SRC="FIGDIR/small/533723v1_ufig1.gif" ALT="Figure 1"> View larger version (69K): org.highwire.dtl.DTLVardef@ed508aorg.highwire.dtl.DTLVardef@42cef8org.highwire.dtl.DTLVardef@2219a9org.highwire.dtl.DTLVardef@c2e3dd_HPS_FORMAT_FIGEXP M_FIG C_FIG

This study was conducted with the primary objective of improving the bioavailability of aripiprazole (APZ) through the development of nanoparticles using thiolated arabinoxylan (TAX) sourced from corn husk. TAX was synthesized via thiolation, employing thiourea as a thiol donor and hydrochloric acid as a catalyst. Characterization of TAX revealed a surface free thiol group content of 37.461 mmol/g, accompanied by an angle of repose measuring 0.393{+/-}0.035. Bulk density, tapped density, Hausner ratio, and Carr index fell within prescribed limits. Subsequently, APZ-loaded thiolated arabinoxylan based nanoparticles were fabricated using the ionotropic gelation method, with barium chloride serving as a cross-linker. Encapsulation efficiency was highest for formulation F4, at 97.1%{+/-}2.36. In vitro drug release demonstrated sustained release profiles at both pH 1.2 and pH 6.8, with F4 exhibiting the most favourable release kinetics. In vitro, characterization indicated that the optimized thiolated arabinoxylan based nanoparticle formulation had an average particle size of 211.1 nm with a Polydispersity Index (PDI) of 0.092 and a zeta potential of 0.621 mV. SEM imaging showed uniform, slightly spherical particles with minimal pores. DSC and TGA confirmed the conversion of APZ to amorphous states within the nanoparticles, enhancing solubility. Ex-vivo permeation studies exhibited favourable drug permeation. An In-vivo pharmacodynamics studies in a ketamine-induced schizophrenia rat model indicated the effectiveness of APZ loaded thiolated arabinoxylan based nanoparticles in behavioural tests, with no significant cataplectic effects observed. Acute oral toxicity assessments demonstrated the safety, with no mortality, no significant alterations in food and water consumption, or any histopathological abnormalities. In conclusion, these developed APZ-loaded thiolated arabinoxylan based nanoparticles hold promise for the effective treatment of schizophrenia without inducing toxic effects, showcasing their potential for clinical applications.

In the past years, we have designed biodegradable poly(benzyl malate) (PMLABe73) homopolymer and amphiphilic poly(ethylene glycol)-b-PMLABe (PEG42-b-PMLABe73) copolymer and several modified (co)polymers to produce biocompatible polymeric nanoparticles (NPs) capable of targeting hepatic cells in vitro with the goal to develop applications in the treatment of liver diseases. The current study aimed at comparing the uptake of PMLABe73 PEG42-b-PMLABe73-based NPs in human hepatic HepaRG cells, primary macrophages and peripheral blood mononuclear cells (PBMC). The uptake of NPs prepared from PEG42-b-PMLABe73 was significantly lower than that of PMLABe73 in both hepatic cells and macrophages. In addition, the NPs uptake by HepaRG cells was inversely correlated to the density of PEG present on their surface. In contrast, the internalization of with PMLABe-based NPs by human macrophages was not affected by low PEG densities, only uptake of fully pegylated PEG42-b-PMLABe73based-NPs was significantly decreased. Herein, we also showed that PMLABe-based NPs did not strongly accumulated in PBMC, T lymphocytes and neutrophils while monocytes showed slightly higher uptake of these NPs. Moreover, we further demonstrated that PMLABe-derived NPs by did not trigger inflammasome activation and secretion of pro-inflammatory cytokines neither in macrophages nor HepaRG cells. Then, we demonstrated that peptide GBVA10-9 derived from George Baker (GB) Virus A, known to exhibit a good hepatotropism did not significantly affect the uptake of PMLABe73-based NPs in HepaRG cells and macrophages, when grafted onto these NPs. The present results demonstrate that PMLABe-derived NPs are very efficiently internalized in both macrophages and hepatocytes but not in PBMC and reinforce our previous reports regarding their biocompatibility.

Delivery tools, including cell-penetrating peptides (CPPs) are often inefficient due to a combination of poor endocytosis and endosomal escape. Herein, the impact of cell culturing techniques on the endocytic uptake of a typical CPP, the TAT peptide (derived from HIV1-TAT), was quantified. Parameters previously found to generally modulate endocytosis such as cell density, washing steps, and cell aging did not affect TAT endocytosis. In contrast, cell dissociation methods, media, temperature, serum starvation, and media composition all contributed to changes in uptake. The combination of these parameters in worst versus best-uptake protocols, led to changes in uptake of more than 13-fold and indicated that small variations in cell culturing techniques have a cumulative effect on CPP uptake. More specifically, modulating cell culture protocols does not result in an increased amount of peptide inside endosomes, rather the number of TMR-TAT containing endosomes increases. Taken together this study highlights how technical aspects of cell culture protocols can be used to improve experimental reproducibility, as well as parameters that can be potentially exploited to improve CPP accumulation in endosomes, and hence increase the possibility of endosomal escape and cytosolic access.

Gene therapy is the most promising strategy for treating a number of diseases at their most fundamental, genetic level, and it has a wide range of promising clinical and emerging preclinical uses in both the clinic and the laboratory. Gene therapy systems are composed of three fundamental components, with the delivery platform being responsible for the protection and successful delivery of the incorporated therapeutic nucleic acid sequences. A successful delivery platform is critical in the achievement of a therapeutic outcome, and an effective delivery platform is essential in achieving this. A variety of different gene delivery platforms - vectors - are evaluated in this dissertation in terms of their nature, mechanism of action, potential applications, and safety. Of particular importance is the evaluation of their post-delivery pharmacokinetic and adverse drug-metabolite profiles. The different types of vectors, including viral, non-viral, and alternative vectors, are discussed separately in each chapter, while important issues related to the incorporation of these vectors into clinical practice are discussed as well, including the topics of vector development and manufacturing, as well as the current regulatory landscape and efforts to improve it, and finally their prospects for the immediate future. ContextGene delivery vectors consist of a broad spectrum of natural or synthetically produced vehicles that represent one out of the three essential aspects of each gene delivery system, without which the successful and effective (in terms of the clinical translation) delivery of therapeutic nucleic acids to a diseased mal- or sub-functioning cell would be impossible. ObjectiveThe presentation and evaluation of the in vivo pharmacokinetic behavior of different viral and non viral gene delivery vectors including a wide review of their mechanism of action, possible safety concerns as well as the promise each holds for future applications. Data SourcesA systematic literature search was conducted using the electronic databases PubMed, Google Scholar and Science Direct while also utilizing the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The keywords included in the research effort were the following: viral vectors, adeno-associated viral vectors, non viral vectors, oncolytic vectors, novel gene delivery vectors, pharmacokinetics of viral vectors, retroviral vectors, recombinant adeno-associated viral vectors, toxicity of gene delivery vectors, Vitravene, Oncorene, Approved gene delivery vectors. Study SelectionCase studies and review articles published in scientifically accepted, high impact factor journals focused on gene delivery vectors and published in English between the years 1999 to 2021 in order to include the most significant findings in terms of both well established data through the years as well as the most recent breakthroughs in terms of preclinical and clinical application. Data ExtractionEssential information were retrieved regarding the various types, behavior, mechanisms of action, safety and in vivo pharmacokinetic behavior of the most prominent viral and non viral gene delivery vectors. ResultsOf a total of 186 records a total of 36 full text articles were reviewed covering a total of 92 case studies and review articles on the topic of the pharmacokinetic behavior of gene delivery vectors including promising future considerations for their clinical use. LimitationsThe outcome of this review article was limited by findings that were shared between different articles published in a variety of literary platforms as well as from papers that lacked sufficient details in order to be included. ConclusionThis scoping review has examined what is currently known and recently discovered regarding the wholesome of the aspects of utilizing specific gene delivery vehicles for a variety of different therapeutic purposes. Their nature, characteristics, as well as their individual action once inserted into the organism and/or in a variety of different in vivo experiments was examined and the implication of their use regarding their shortcomings and possible dangers, as well as their therapeutic advantages and probable future applications were weighted.

For clinical translation of oral nanocarriers, simulation of the complex intestinal microenvironment is crucial to evaluate interactions and transport across the intestinal mucosa for predicting the drugs bioavailability. However, permeation studies are often conducted using simplistic cell culture models, overlooking key physiological factors such as tissue composition, morphology, and additional diffusion barriers as constituted by mucus. This oversight may potentially lead to an incomplete evaluation of the nanocarrier-tissue interactions and an overestimation of permeation. In this study, we systematically investigated different 3D tissue models of the human intestine under static cultivation and dynamic flow conditions with respect to tissue morphology, mucus production, and their impact on nanocarrier permeation. Our results revealed that the cell ratio between the different cell types (enterocytes and goblet cells), as well as the choice of culture conditions, had a notable impact on tissue layer thickness, mucus secretion, and barrier impairment, all of which were increased under dynamic flow conditions. Permeation studies with polymeric nanocarriers (PLGA and PEG-PLGA) elucidated that the amount of mucus present in the respective model was the limiting factor for the permeation of PLGA nanocarriers, while tissue topography represented the key factor influencing PEG-PLGA nanocarrier permeation. Furthermore, both nanocarriers exhibited diametrically opposite permeation kinetics in a direct comparison to soluble compounds. In summary, these findings reveal the critical role of the implemented test systems on permeation assessment and emphasize that, in the context of preclinical nanocarrier testing, the choice of in vitro model matters.

Chronic knee and lower back pain due to osteoarthritis (OA) has a global prevalence and impacts human well-being by impairing mobility. Oxidative stress and inflammation are key factors in OA pathogenesis and progression. Non-viral gene delivery through liposomes is a promising approach for repairing damaged cartilage tissues. Our study focuses on developing co-loaded lipoplexes for efficient co-delivery of curcumin and therapeutic siRNA. Curcumin downregulates many inflammatory cytokines, scavenges free radicals, and upregulates collagen and aggrecan, therefore reducing pain and helping with regeneration. Quality by Design (QbD) principles guided the development of curcumin-loaded cationic liposomes (CL), which were further used as vectors for therapeutic siRNA in the design of the co-loaded lipoplexes. QbD steps involved risk assessment, Design of Experiments (DoE), and selection of the optimal vector, i.e., optimum curcumin-loaded cationic liposomes (Opt-CL), which would ensure the best transfection efficiency for therapeutic siRNA. The efficiency of Opt-CL was evaluated in both the primary chondrocytes and cell lines, which were induced by oxidative stress and inflammatory conditions. The Opt-CL successfully reduced the oxidative stress levels in both. The Opt-CL were complexed with the IL-6 and IL-8 siRNA to form co-loaded lipoplexes, which efficiently reduced the inflammation in the chondrocytes. These co-loaded lipoplexes effectively transfected chondrocytes with no toxicity and are promising for further testing in OA models. The study has yielded an optimal non-viral vector that could serve as a platform for the incorporation of other lipophilic drugs and negatively charged oligonucleotides for various ailments. HighlightsO_LIUtilization of QbD to screen and optimize critical factors for the development of CL C_LIO_LIDevelopment of proof of concept using the curcumin and luciferase siRNA as the small molecule and oligonucleotide candidates for efficient cell viability and transfection C_LIO_LIEvaluation of cell internalization and gene knockdown in a luciferase-expressing chondrocyte cell line to prove the model efficacy C_LIO_LIIn chondrocytes, the optimized formulation demonstrated the reduction of inflammation and oxidative stress. C_LI

Neurodevelopmental disorders including autism spectrum disorder (ASD) affect 5.9% of the global population. Research shows the potential therapeutic use of cannabidiol (CBD) to treat different neurodevelopmental disorders, including ASD. Intranasal drug delivery (i.n.) is a non-invasive and painless administration route that enhances drug bioavailability in the brain by bypassing the blood-brain barrier. However, i.n. has limited bioavailability due to the low nasal mucosa permeability. Various polymeric nanoparticles have been investigated for i.n. delivery with different successes. In this study, we developed and characterized polymeric micelles of the poly(ethylene oxide)-b-poly(propylene oxide) block copolymer Pluronic(R) F127 loaded with 25% w/w CBD for nose-to-brain delivery in ASD. CBD-loaded polymeric micelles display a hydrodynamic diameter of 41 {+/-} 1 nm by Intensity and 23 {+/-} 1 nm by Number, as measured by dynamic light scattering, and showed very good compatibility and permeability in the human nasal septum cell line RPMI 2650, an in vitro model of the nasal epithelium. The accumulation of CBD-loaded polymeric micelles upon i.n. administration to autistic rats is confirmed by bioimaging. The pharmacokinetics of CBD upon i.n. (dose of 5 mg/kg) and oral (15 mg/kg) administration of the loaded polymeric micelles shows a 27.8% increase of the CBD concentration in the brain 20 min of autistic rats after i.n. administration, despite the 3-fold decrease in the dose. Finally, the efficacy of this nanoformulation to improve the core symptoms of ASD is demonstrated in behavioral studies in a rat model of the disorder.

Despite several promising candidates there is a paucity of drug treatments available for patients suffering from retinal diseases. An important reason for this is the lack of suitable delivery systems that can achieve sufficiently high drug uptake in the retina and its photoreceptors. A promising and versatile method for drug delivery to specific cell types involves liposomes, surface-coated with substrates for transporter proteins highly expressed on the target cell. We identified strong lactate transporter (monocarboxylate transporter, MCT) expression on photoreceptors as a potential target for drug delivery vehicles. To evaluate MCT suitability for drug targeting, we used PEG-coated liposomes and conjugated these with different monocarboxylates, including lactate, pyruvate, and cysteine. Monocarboxylate-conjugated dye-loaded liposomes were tested on both human-derived cell-lines and murine retinal explant cultures. We found that liposomes conjugated with pyruvate consistently displayed higher cell uptake than unconjugated liposomes or liposomes conjugated with lactate or cysteine. Pharmacological inhibition of MCT1 and MCT2 reduced internalization, suggesting an MCT-mediated uptake mechanism. Pyruvate-conjugated liposomes loaded with the drug candidates CN03 and CN04 reduced photoreceptor cell death in murine rd1 and rd10 retinal degeneration models. Overall, this study proposes pyruvate-conjugated liposomes as a vehicle for drug delivery specifically to photoreceptors. Notably, in retinal degeneration models, free drug solutions could not achieve the same therapeutic effect. Our study thus highlights pyruvate-conjugated liposomes as a promising system for drug delivery to retinal photoreceptors, as well as other neuronal cell types displaying high expression of MCT-type proteins.

SN-38 is a chemotherapeutic compound with potent antitumor effects. However, its clinical application is currently limited due to its poor solubility and low stability at physiological pH. Liposomes and cyclodextrins have been long studied for the solubilization and delivery of hydrophobic compounds. Aiming to combine the advantages from both systems, we attempted to develop an SN-38-in-cyclodextrin-in-liposome formulation. We found that the encapsulation of SN-38-SBE-{beta}-CD inclusion complexes in the lumen of liposomes was not possible, owing to the disassembly of liposomes and the formation of lipid nanoparticles, as revealed by size exclusion chromatography and single nanoparticle fluorescence microscopy. Interestingly, the retention time of SN-38 inside SN-38-SBE-{beta}-CD-lipid nanoparticles is higher than in liposomes, whereby SN-38 was directly loaded into the lipid film. The toxicity of purified SN-38-SBE-{beta}-CD- lipid nanoparticles was assayed in cultured cancer cells, showing no therapeutic advantage compared to bulk SN-38-SBE-{beta}-CD complexes. Further formulation optimization, in particular an increased concentration of the nanoparticles, will be necessary to obtain cytotoxicity effects. Moreover, the results highlight the value of fluorescence imaging of single, surface-immobilized nanoparticles, in the development of liposomal delivery systems such as drug-in-cyclodextrin- in-liposomes.

Oral microemulsions are one drug delivery system often implemented to improve intestinal permeability and oral bioavailability of poorly-water soluble drugs. They also present several practical advantages including high patient compliance and simplified manufacturing methods which contribute to their promise as marketable drug products. Despite these advantages, however, the microemulsion formulation development process is extremely time consuming and resource intensive, typically involving extensive screening of components and excessive preliminary trials in order to achieve stable formulations. As a result, MEs are often suboptimal in their therapeutic performance, and there is an unmet need for improved methods to streamline microemulsion formulation design. In this work, a batch Bayesian Optimization strategy was used to design a subset of unique in-specification microemulsions with highly optimized physicochemical properties in five iterations containing batches of five experiments. A two-phase modeling approach was developed to achieve this goal and allowed for navigating a complex experimental design space, including multiple oils, surfactants, cosurfactants, and processing parameters with a training dataset consisting of 22 experiments. As a result of this study, five high-performing blank microemulsions were identified, and four of them exhibited physical stability upon storage for up to 30 days. Further, when loaded with two different model drug candidates, three of the microemulsions achieved high drug loading, acceptable stability and improved in-vitro permeability, highlighting their promise for potential translation to later stages of development.

Extracellular vehicles (EVs) are an emerging class of drug carriers and are primarily reported to be internalized into recipient cells via a combination of endocytic routes such as clathrin-mediated, caveolae-mediated and macropinocytosis pathways. In this work, (1) we investigated potential effects of homotypic vs. heterotypic interactions by studying the cellular uptake of homologous EVs (EV donor cells and recipient cells of the same type) vs. heterologous EVs (EV donor cells and recipient cells of different types) and (2) determined the route of EV internalization into low pinocytic/hard-to-deliver cell models such as brain endothelial cells (BECs). We used BECs and macrophages as low-pinocytic and phagocytic cell models, respectively, to study the effect of homotypic vs. heterotypic interactions on EV uptake in the recipient cells. Homotypic interactions led to a greater extent of uptake into the recipient BECs compared to heterotypic interactions. However, we did not see a complete reduction in EV uptake into recipient BECs when endocytic pathways were blocked using pharmacological inhibitors. Our results suggest that EVs primarily use membrane fusion to enter low-pinocytic recipient BECs instead of relying on endocytosis. Lipophilic PKH67 dye-labeled EVs but not intravesicular esterase-activated calcein ester-labeled EVs severely reduced particle uptake into BECs while phagocytic macrophages internalized both types of EV-labeled particles to comparable extents. Our results also highlight the importance of carefully choosing labeling dye chemistry to study EV uptake, especially in the case of low pinocytic cells such as BECs. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=171 HEIGHT=200 SRC="FIGDIR/small/563628v2_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@d5cb50org.highwire.dtl.DTLVardef@172d1dorg.highwire.dtl.DTLVardef@192caf6org.highwire.dtl.DTLVardef@4b16ba_HPS_FORMAT_FIGEXP M_FIG C_FIG

This work develops and characterises a hierachichal oral drug delivery system based on the microencpasulation of drug-loaded amphiphilic nanogels within a mucoadhesive alginate/chitosan shell. Results show a more controlled release and a statistically significant oral half-life with respect to the free drug.

PurposeTo explore the utility of the Matrix of Chemistry, Manufacturing and Control (MoCMC) approach for evaluating product physicochemical (Q3) similarity as part of a product bioequivalence assessment. MethodologyEach Q3 parameter was converted to a radius of a polygon using a mathematical equation that converted each reference Q3 parameter to a value of "5". That equation was applied to the corresponding test product Q3 parameter and the areas of the treatment polygons determined. The ratio of the product area/outer area [Matrix Comparability Index (MCI)] was calculated using an outer polygon with each radius = "10". When generated across multiple lots for each treatment, the MCI values were statistically compared. Both actual (from our previously published investigation) and hypothetical MCI values were used to characterize the performance of the MoCMC across a range of situations. ResultsMCI values successfully captured product Q3 differences, with the influence of any Q3 parameter decreasing as the number of radii increases. The ability to identify statistically significant product differences decreased as variability of either test or reference MCI values increased. By combining statistical analysis with a comparison of the spread of test and reference MCI values, the MoCMC provided a sensitive tool for assessing product comparability and identified product differences previously missed by comparing in vitro dissolution profiles alone ConclusionsWhile the impetus for this research was to identify a tool for supporting the evaluation of product bioequivalence containing locally acting drugs, its strengths support its potential use across a wider scope of situations.

Chronic diseases often require repeated oral or local administration, which can compromise patient compliance. In wet age-related macular degeneration (AMD), current therapies rely on intravitreal injections of anti-vascular endothelial growth factor agents every four to six weeks to maintain therapeutic drug levels. Controlled-release drug delivery systems offer a promising alternative by reducing injection frequency and extending drug release. In this study, we developed a continuum diffusion model to describe drug transport through porous polymeric microcapsules, implemented using the finite element method in COMSOL Multiphysics. The case study focused on cylindrical microcapsules fabricated with either a single polycaprolactone (PCL) layer or a bi-layered chitosan-PCL structure, tested at two capsule sizes and three salt leaching concentrations. Bovine serum albumin and bevacizumab were used as model drugs. Parameter estimation was performed using published release data, with a progressive fitting strategy that carried forward parameters from simpler systems into more complex designs. The model reproduced experimental release profiles across formulations and identified key transport parameters governing release dynamics, including porosity, tortuosity, and mass transfer rates. Design exploration revealed that polymer thickness was the dominant factor controlling release, while addition of the chitosan layer moderated the initial burst and extended therapeutic delivery. This framework demonstrates how computational modeling can reduce experimental burden, guide design optimization, and support the development of long-acting intravitreal drug delivery systems to treat wet AMD by linking drug release kinetics to design variables.

Milk related materials are frequently used as a vehicle for drug product administration. Therefore, drug solubility information in milk related vehicles is desirable for prediction of how they may influence in vivo drug release and bioavailability. However, there are very limited data published on this topic. This study explored a practical method to address the key challenges associated with solubility assessment in milk, including the sample equilibration time and cleanup procedures. Amitriptyline, acetaminophen, dexamethasone, nifedipine, piroxicam, and prednisolone were selected as model drugs to represent a wide range of physicochemical properties. Their solubilities were determined at room temperature in pH 6.8 phosphate buffer, skim milk, whole milk, reconstituted whole milk powder, and unprocessed raw milk. The overall results confirmed that milk greatly improves the solubility of poorly water-soluble drugs. However, the extent of improvement and mechanism of solubilization appeared unique for each drug, highlighting the importance of evaluating milk solubility experimentally. The method used in this exploratory study can be applied in future investigations of a broader range of drugs and milk-related vehicles.

Drug delivery research is an inherently empirical process, however high-throughput approaches could take advantage of understanding drug/material interactions such as from electrostatic, hydrophobic, or other non-covalent interactions between therapeutic molecules and a drug delivery polymer. Cyclodextrin polymers have been investigated for drug delivery specifically due to their capacity to exploit this affinity interaction to change the rate of drug release. Testing drug candidates; however, for affinity is time-consuming, making computational predictions more effective. One option, molecular \"docking\" programs, provide predictions of affinity, but lack reliability, as their accuracy with cyclodextrin remains unverified experimentally. Alternatively, quantitative structure-activity relationship models (QSARs), which analyze statistical relationships between molecular properties, appear more promising. Previously constructed QSARs for cyclodextrin are not publicly available, necessitating an openly accessible model. Around 600 experimental affinities between cyclodextrin and guest molecules were cleaned and imported from published research. The software PaDEL-Descriptor calculated over 1000 chemical descriptors for each molecule, which were then analyzed in R to create several QSARs with different statistical methods. These QSARs proved highly time efficient, calculating in minutes what docking programs would take hours to accomplish. Additionally, on test sets, QSARs reached R2 values of around 0.7-0.8. The speed, accuracy, and accessibility of these QSARs improve evaluation of individual drugs and facilitate screening of large datasets for potential candidates in cyclodextrin affinity-based delivery systems. An app was built to rapidly access model predictions for end users using the \"shiny\" library in R. To demonstrate the usability for drug release planning, the QSAR predictions were coupled with a mechanistic model of diffusion within the app. Integrating new modules should provide an accessible approach to use other cheminformatic tools in the field of drug delivery.

High ivermectin (IVM) concentrations suppress in vitro SARS-CoV-2 replication. Nasal IVM spray (N-IVM-spray) administration may contribute to attaining high drug concentrations in nasopharyngeal (NP) tissue, a primary site of virus entrance/replication. The safety and pharmacokinetic performance of a new N-IVM spray formulation in a piglet model were assessed. Crossbred piglets (10-12 kg) were treated with either one or two (12 h apart) doses of N-IVM-spray (2 mg, 1 puff/nostril) or orally (0.2 mg/kg). The overall safety of N-IVM-spray was assessed (clinical, haematological, serum biochemical determinations), and histopathology evaluation of the application site tissues performed. The IVM concentration profiles measured in plasma and respiratory tract tissues (nasopharynx and lungs) after the nasal spray treatment (one and two applications) were compared with those achieved after the oral administration. Animals tolerated well the novel N-IVM-spray formulation. No local/systemic adverse events were observed. After nasal administration, the highest IVM concentrations were measured in NP and lung tissues. Significant increases in IVM concentration profiles in both NP-tissue and lungs were observed after the 2-dose nasal administrations. The nasal/oral IVM concentration ratios in NP and lung tissues (at 6 h post-dose) markedely increased by repeating the spray application. The fast attainment of high and persistent IVM concentrations in NP tissue is the main advantage of the nasal over the oral route. These original results are encouraging to support the undertaking of further clinical trials to evaluate the safety/efficacy of the nasal IVM spray application in the treatment and/or prevention of COVID-19.

A significant challenge in the development of long-acting injectable drug formulations, especially for anti-infective agents, is delivering an efficacious dose within a tolerable injection volume. Co-administration of the extracellular matrix-degrading enzyme hyaluronidase can increase maximum tolerable injection volumes but is untested for this benefit with long-acting injectable formulations. One concern is that hyaluronidase could potentially alter the tissue response surrounding an injection depot, a response known to be important for drug release kinetics of long-acting injectable formulations. The objective of this pilot study was to evaluate the impact of co-administration of hyaluronidase on the drug release kinetics, pharmacokinetic profiles, and injection site histopathology of the long-acting injectable paliperidone palmitate for up to four weeks following intramuscular injection in mouse and rat models. In both species, co-administration of hyaluronidase increased paliperidone plasma exposures the first week after injection but did not negate the overall long-acting release nature of the formulation. Hyaluronidase-associated modification of the injection site depot was observed in mice but not in rats. These findings suggest that further investigation of hyaluronidase with long-acting injectable agents is warranted.