Mucoadhesive polymers are crucial for prolonging drug retention on mucosal surfaces. This study focuses on synthesising and characterising novel derivatives by reacting chitosan with crotonic and methacrylic anhydrides. The structure of the resulting derivatives was confirmed using proton-nuclear magnetic resonance spectroscopy and Fourier-transform infrared spectroscopy. It was established that the degree of substitution plays a crucial role in the pH-dependent solubility profiles and electrophoretic mobility of the chitosan derivatives. Spray-drying chitosan solutions enabled preparation of microparticles, whose mucoadhesive properties were evaluated using fluorescence flow-through studies and tensile test, demonstrating improved retention on sheep nasal mucosa for modified derivatives. Acute toxicity studies conducted in vivo using planaria and in vitro using MTT assay with the Caco-2 cell line, a model of the mucosal epithelium in vitro, showed that the novel derivatives are not cytotoxic. These findings emphasise the potential of tailored chitosan chemical modifications for enhancing transmucosal drug delivery.

The study investigates the effect of pulmonary surfactant (PS) coating on the performance of lysozyme-loaded poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs). The NPs were fabricated using a double emulsification technique and optimized using the Box-Behnken experimental design (BBED). The NPs were assessed for size, polydispersity index (PDI), zeta potential, drug loading (DL%), and encapsulation efficiency (EE%). In addition, the optimized PLGA NPs were modified with either a neutral dipalmitoylphosphatidylcholine DPPC or an anionic dipalmitoyl phosphatidylglycerol (DPPG) with different molar ratios of PS to PLGA (PS: PLGA = 1:2, 1:1 and 2:1). These NPs were assessed for biological activity, drug release, mucus adhesion, mucus penetration, cellular uptake, toxicity, and in vivo destiny after intratracheal (IT) instillation to mice. Results showed a bi-phasic drug release, with no significant effect of PS on the release and biological activities of PLGA NPs. The PS@PLGA NPs improved mucus adhesion, decreased mucus penetration, and increased cellular internalization of PLGA NPs. In addition, ex vivo experiments demonstrated that DPPC@PLGA NPs and DPPG@PLGA NPs could adhere to mucus. These NPs created a thicker layer at the interface of the airway compared to unmodified PLGA NPs. Moreover, interaction of PS@PLGA NPs with BALF suggested improved mucoadhesive characteristics. Finally, the in vivo studies confirmed the precise distribution of all NPs in the lungs after IT administration. The study presents empirical evidence and scientific guidance for developing a lung surfactant-modified nanocarrier system for lung drug delivery.

Multivesicular liposomes (DepoFoam® technology) are distinctive lipid-based sustained release drug delivery systems. Their non-concentric structure differentiates them from unilamellar and multilamellar liposomes. Several products using DepoFoam® technology have been successfully developed and translated into clinical and commercial applications. The unique composition and structure of these particles result in large drug-trap volumes, diverse loading capacities, variable release rates, and different administration routes. With all these advantages, DepoFoam® based products can achieve sustained release pharmacokinetics and significantly improved half-life in various subject species. However, the complexity of constituents and the manufacturing process, as well as the complicated structure and release mechanism, pose challenges to the translation and application of DepoFoam® technology. This review aims to summarize current approved commercial products based on DepoFoam® technology, their structures and components, large-scale manufacturing processes, release characteristics, in vivo pharmacokinetics and clinical outcomes. Challenges in the development and approval of multivesicular liposomes are also highlighted. The persistent academic and industrial research will be needed to overcome the difficulties in developing this unique drug delivery system and pave the path for successful DepoFoam® applications in the future.

Transdermal delivery of therapeutic molecules is often hindered by the properties of the skin, with the stratum corneum serving as the primary permeation barrier. To overcome this barrier, the integrity of the stratum corneum can be modified by chemical permeation enhancers, such as deep eutectic solvents (DESs), or by mechanically impairing the skin with microneedles (MNs). However, a systematic comparison between these strategies is currently lacking. Hence, this study examined the potential of DESs and MNs to promote the permeation and retention of drugs with varying lipophilicities - specifically, the hydrophilic drug metronidazole (logP ∼ 0), the moderately lipophilic drug lidocaine (logP ∼ 2.3), and the highly lipophilic drug clotrimazole (logP ∼ 5). A mixture of menthol and thymol was selected as a model terpene-based DES and delivery vehicle, while a DermaPen equipped with solid MNs was used to mechanically impair the skin. Permeation rates of model drugs applied to the skin with either DES, MNs, or both were compared to the rates determined for the drugs applied in control vehicles. Both strategies were found to compromise the skin barrier function, but their permeation-enhancing effect was dependent on the lipophilicity of tested model drug. The DES was most effective for the hydrophilic drug metronidazole, while the MNs were more effective in increasing the permeation of the highly lipophilic drug clotrimazole. For the moderately lipophilic drug lidocaine, neither the DES nor microneedles increased its permeation rate, as the drug permeated through the skin well on its own. Notably, the combination of both enhancement strategies did not result in significantly better permeation rates of the drugs compared to the individual approaches. In conclusion, both the terpene-based DES and solid MNs are effective strategies to enhance drug permeation through the skin, but our results suggest that the choice of strategy should be dictated by the drug's lipophilicity. Moreover, from a permeation-enhancing perspective, there is no benefit in combining these two strategies.

Invasive fungal infections have high mortality rates, and many current antimycotics are limited by host toxicity and drug resistance. Recent experiments in our laboratory have demonstrated the antifungal activity of dKn2-7, a synthetic peptide, against Candida albicans. The purpose of the current study was to develop a wound dressing capable of dKn2-7 release for extended periods to help combat fungal infection in wounds. dKn2-7 was incorporated into calcium alginate microfibers, an excipient with known wound healing and hemostatic properties. dKn2-7 release rates from the fibers were dependent on drug loading, but all formulations exhibited a burst release with 41-71 % of total release in the first 15 min and 84-96 % release by 24 h. Calcium release at 15 min was similar to that of a commercial hemostatic dressing, indicating dKn2-7 loading would not adversely affect the hemostatic capability of the alginate fibers. In vitro antifungal studies indicated a dose dependent effect with fibers loaded at ≥20 µg/mg causing significant planktonic killing and ≥30 µg/mg causing significant biofilm killing. Viable fungal counts in biofilms grown on ex vivo porcine skin declined by 99 % following 500 µg/mg fiber treatment. Skin histology indicated no significant differences in tissue damage between treatment groups and controls. Results confirm calcium alginate microfibers are capable of binding and subsequently releasing dKn2-7 over a 24-h period when rehydrated. Furthermore, dKn2-7 released from the fibers was able to significantly reduce biofilms in an ex vivo model with minimal toxicity, indicating these dKn2-7 loaded fiber dressings may be effective at controlling C. albicans biofilm infections in vivo.

Pharmaceutical tablets need to have a homogenous chemical structure, especially in cases where the patient may divide the tablet in half prior to consumption. This work aims to demonstrate the viability of using laser induced breakdown spectroscopy (LIBS) for analyzing the homogeneity and determining the chemical composition of losartan potassium tablets. This was accomplished by obtaining the spectra of 10 tablet points in 30 successive laser pulses, which revealed four main peaks (C, H, N, and O) as well as a high concentration of calcium and potassium in the core tablets and titanium in the coating-all of which are excellent analytical objectives for LIBS. It is possible to say that the generated plasma meets the minimum requirement for local thermodynamic equilibrium because the physical parameters of the plasma, including temperature (T) and electronic density (N), were calculated throughout the Boltzmann plot and Stark broadened line, respectively, and the McWhirter criterion was met. In addition, T and N changes have been used for homogeneity analysis. Different peak comparisons cannot provide us with further data because the major structural components are similar, making it challenging to differentiate between them. So relative standard deviation (RSD) and principal component analysis (PCA) were used to comprise the whole spectra, which showed that the homogeneity of the tablet's core is better than that of the coating and is acceptable.

Electrospinning (ES) is a promising continuous formulation strategy to produce amorphous solid dispersions (ASDs) and thereby improve the dissolution of poorly water-soluble drugs. However, processing the electrospun material into solid dosage forms (e.g. tablets) is challenging due to the poor flow properties. In this research, continuous twin-screw melt granulation was applied to improve the flowability of the fibers and therefore ease the further processing steps. During this work, two ASD compositions were investigated: one containing 60 % poly-vinylpyrrolidone-vinyl acetate 6:4 copolymer and 40 % itraconazole (ITR), and another one containing hydroxypropyl methylcellulose (HPMC) and ITR in the same ratio. Both fiber compositions were granulated with polyethene glycol as the binder material, while the effects of the process parameters were examined. The application of higher granulation temperature and screw configurations with increased shear forces compromised the fibrous structure, induced crystallization of the ASD, and decreased the dissolution. However, the stability of the ITR-HPMC fibers proved to be higher as their granulation at 60 °C led to granules with adequate flow properties and dissolution. Moreover, tablets with fewer excipients were pressed from them, resulting in a 34 % reduction in weight. Consequently, this process can complement ES technology and facilitate its industrial implementation.

This study investigated the potential of self-nanoemulsifying drug delivery systems (SNEDDS) to optimize the oral bioavailability of insulin. Insulin complexes with phospholipids and enzymatically-modified phospholipids were developed and incorporated into the SNEDDS using Lauroglycol FCC as the oily phase and Cremophor EL and Labrafil M1944CS as the surfactant and co-surfactant, respectively. Additionally, mucoadhesive polysaccharides (sodium alginate and guar gum) were added further to enhance the bioavailability of insulin in these systems. The objective was to increase the bioavailability and bioactivity of an insulin-modified phosphatidylcholine complex by incorporating mucoadhesives into the SNEDDS. After polymer inclusion, the resulting nanoemulsions exhibited droplet diameters ranging from 57 to 83 nm. Cytotoxicity and apparent permeability tests were conducted on Caco-2 and NIH 3 T3 cell lines, revealing that toxicity was related to the concentrations of insulin and surfactant in the nanosystems-formulations containing guar gum as a mucoadhesive showed better tolerance to cell death in the Caco-2 line. In a murine diabetes model, the SNEDDS were observed to reduce glucose levels by up to 61.63 %, with a relative bioavailability of 2.25 % compared to subcutaneously administered insulin. These results suggest that SNEDDS incorporating mucoadhesives could represent a promising strategy for improving oral insulin delivery.

Vaccine adjuvants are important for enhancing vaccine efficacy, and although aluminium salts (Alum) are the most used, their limited ability to induce specific immune responses has spurred the search for new adjuvants. However, many adjuvants fail during product development due to manufacturability, supply, stability, or safety concerns. This work hypothesizes that protein-free yeast glucans can be used as vaccine adjuvants due to their known immunostimulatory activity and high abundancy. Thus, high molecular weight glucans with over 99% purity, comprising 64-70% β-glucans and 29-35% α-glucans, were extracted from a wild-type yeast and an engineered yeast to produce a steviol glycoside. These glucans underwent carboxymethylation to enhance solubility. Both water-dispersible and particulate glucans were evaluated as adjuvants, either alone or in combination with Alum or squalene stable emulsion (SE), for a SARS-CoV-2 vaccine. The study demonstrated that glucans triggered a robust immune response and enhanced the effects of Alum and SE when used in combination, both in vitro and in vivo. Water-dispersible glucans combined with Alum, and particulate glucans combined with SE, increased the production of specific antibodies against SARS-CoV-2 spike protein and enhanced serum neutralization titers against SARS-CoV-2 pseudovirus. Furthermore, the results indicated that larger molecular weight glucans from engineered yeast exhibited stronger immunogenic activity in comparison to wild-type yeast glucans. In conclusion, appropriately formulated glucans have the potential to be scalable, low-cost vaccine adjuvants, potentially overcoming the limitations of current adjuvants.

Arterial thrombotic disease is a common and serious clinical medical problem. Nitric oxide (NO), as a therapeutic gas, can delay the progression of thrombosis and reduce tissue ischemia and hypoxia damage. However, systemic delivery of NO causes complications, and NO in the body is easily cleared by hemoglobin in the blood. In this study, we designed a lipid microbubble carrying NO (NO-MBs) combined with ultrasound-targeted microbubble destruction (UTMD) technology to achieve targeted delivery of NO under real-time contrast-enhanced ultrasound monitoring. The good stability of the NO-MBs was demonstrated by examining the changes in diameter, concentration and contrast-enhanced ultrasound intensity with time. Moreover, in vivo and in vitro thrombolysis experiments, it was confirmed that the combination of NO-MBs and UTMD could accelerate arterial thrombolysis. Meanwhile, the levels of inflammatory factors, superoxide dismutase (SOD) and malondialdehyde (MDA) in vascular tissue after treatment were detected, which showed that NO-MBs could significantly reduce the inflammatory response and oxidative stress induced by thromboembolism. In addition, so as to‌ evaluate the safety of the NO-MBs UTMD treatment strategy, MTT assay, hemolysis test, detection of serum biochemical indicators, and H&E staining of major organs were performed. The results showed that this treatment strategy had excellent biosafety. In conclusion, the NO-MBs UTMD treatment strategy has great potential in the treatment of arterial thrombotic diseases.

This research is based on the incorporation of the methanolic extract of the Usnea ghattensis into poly (caprolactone) (PCL) nanofibers (NFs) to investigate the capacity in reducing reactive oxygen species (ROS). PCL-NFs were fabricated by the electrospinning technique and are investigated as potential dressing material focused on the release of usnic acid (PCL-USNIC NFs), and its encapsulation efficiency and kinetic release were analyzed by high performance liquid chromatography (HPLC). This investigation was performed by analyzing the usnic acid concentration as a function of the distance from the mat center point. The kinetic release analysis is also developed with the usnea ghattensis extract (PCL-USNEA NFs), performing a metabolomic analysis of the released molecules as a function of time by nuclear magnetic resonance (NMR). Usnic acid was revealed as the most relevant compound together with other molecules, such as sucrose, mannitol, arabitol or glycerol that generate a positive matrix effect on the release of usnic acid. Finally, we analize the cytotoxicity and the neuroprotective effect of PCL-USNEA and PCL-USNIC NFs using a human neuroblastoma cell line model. Negligible toxicity was appreciated for both polymeric systems, showing high protective effects in presence of highly oxidative environment (e.g. in presence of HO).

Cosmeceuticals, focusing on enhancing skin health and appearance, heavily rely on emulsions as one of the common mediums. These emulsions pose a challenge due to their dependence on surfactants which are essential for stability but are causing concerns about environmental impact as well as evolving consumer preferences. This has led to research focused on Pickering emulsions (PEs), which are colloidal particle-based emulsion alternatives. Compared to conventional emulsions, PEs offer enhanced stability and functionality in addition to serving as a sustainable alternative but still pose challenges such as rheological control and requiring further improvement in long-term stability, whereby the limitations could be addressed through the introduction of a hydrogel network. In this review, we first highlight the strategies and considerations to optimize active ingredient (AI) absorption and penetration in a PE-based formulation. We then delve into a comprehensive overview of the potential of Pickering-based cosmeceutical emulsions including their attractive features, the various Pickering particles that can be employed, past studies and their limitations. Further, PE hydrogels (PEHs), which combines the features between PE and hydrogel as an innovative solution to address challenges posed by both conventional emulsions and PEs in the cosmeceutical industry is explored. Moreover, concerns related to toxicity and biocompatibility are critically examined, alongside considerations of scalability and commercial viability, providing a forward-looking perspective on potential future research directions centered on the application of PEHs in the cosmeceutical field.

Investigating the structural stability of poorly-soluble luteolin (LuT) after encapsulation within cyclodextrins (CDs) is crucial for unlocking the therapeutic potential of LuT bioactive molecule. Herein, native and modified β-CD were employed to investigate LuT inclusion complex formation. Molecular mechanics (MM) and quantum mechanics (QM) were utilized for structural dynamics analysis. Microsecond timescale MD simulations yielded insights into LuT-CD interactions. The binding affinity between LuT and selected β-CDs was assessed by calculating the binding free energy using MM-PBSA and umbrella sampling simulations. The MM-PBSA results indicated that Heptakis-O-(2-hydroxypropyl)-β-CD (HP-β-CD) (-82.59+/-11.67 kJ/mol) and Di-O-methyl-β-CD (DM-β-CD) (-54.01+/-11.07 kJ/mol) exhibited good binding affinity for LuT. Subsequently, derivative screening of HP-β-CD revealed that only 2-HP-β-CD (HP-β-CD-1)/LuT (-21.38 kJ/mol) displayed a superior binding free energy (obtained from umbrella sampling) than HP-β-CD/LuT (-19.15 kJ/mol) inclusion complex. We conducted QM calculations on the top three complexes namelly HP-β-CD, DM-β-CD, and HP-β-CD-1 employing wB97X-D/6-311 + G(d,p) model chemistry to strengthen the MM results. The computational analysis aligns with experimental findings (phase solubility analysis), validating HP-β-CD-1 as most effective cavitand molecule for improving the solubility of LuT. This study offers critical structural insights for developing novel HP-β-CD derivatives with enhanced host capacity to encapsulate guest molecules efficiently.

To quantify concentration and encapsulation efficiency (EE) of mRNA in lipid nanoparticles (LNPs) the RiboGreen assay is extensively used. As part of this assay, a surfactant is used to release mRNA from LNPs for detection with the RiboGreen dye. So far, the surfactant of choice has been Triton X-100, which is harmful to human health and the environment. Alternatives to Triton X-100 are therefore needed, but surprisingly no such effort has yet been described in the literature. Here we show how three, less harmful, surfactants (Brij 93, Zwittergent 3-14 and Tween 20) compare to Triton X-100 for releasing mRNA from LNPs for detection with the RiboGreen assay. We found that Zwittergent 3-14 and Tween 20 at high concentrations (0.5 %) are at the minimum as effective as Triton X-100 at high concentration (0.5 %) across three different mRNA-LNP formulations. Interestingly, Tween 20 was the most effective at releasing mRNA from LNPs, across all concentration ranges explored (0.0025 %, 0.01 %, 0.1 % and to 0.5 % (v/v)) highlighting its potency at solubilizing the three different LNP formulations. Our results show that Tween 20 can be used as an alternative to Triton X-100 in the RiboGreen assay, resulting in more accurate quantification of the total mRNA concentration and EE%, as well as making the assay more environmentally friendly. Such improvement could potentially increase the likelihood of identifying therapeutically attractive hard-to-solubilize LNP-mRNA formulations that would be discharged when using Triton X-100 due to their apparent low EE values, as well as ensure more accurate mRNA dosing in both in vitro and in vivo studies.

Tandospirone(Tan) is a commonly used drug for anxiety treatment. However, it has a significant first-pass effect and needs to be taken three times a day. To increase the bioavailability of the drug and reduce the number of administrations, this work amid to prepare a Tan patch that can be administered once a day by using the strategy of therapeutic deep eutectic solvent(THEDES) in cooperation with chemical permeation enhancer(CPE). In this study, four organic acids and five permeation enhancers were selected, and the optimized formulation was obtained by single-factor investigation and Box-Behnken design. The optimized formulation could significantly enhance drug loading by 2.5-fold and skin permeation up to 586.6 ± 17 μg/cm in rats. Based on pharmacokinetic results, compared to oral administration, the drug exhibited a substantially elevated bioavailability, registering a 17-fold increase(from 3.01 % to 52.17 %), alongside a 10-fold rise in the mean residence time(MRT). Meanwhile, the patch was not irritating. The results of the mechanistic study showed that levulinic acid(LeA) acted as a bridge to increase the interaction between the Tan and the matrix and inhibited the crystallization of the drug in the patch, and THEDES together with CPE improved the matrix fluidity and skin permeability. This study provides a reference for the joint application of THEDES and CPEs in patch development.

Bioequivalence risk assessment as an extension of quality risk management lacks examples of quantitative approaches to risk assessment at an early stage of generic drug development. The aim of our study was to develop a model-based approach for bioequivalence risk assessment that uses pharmacokinetic and physicochemical characteristics of drugs as predictors and would standardize the first step of risk assessment.

Controlled local delivery of therapeutics (small molecule drug crystals or biologics) for knee-associated diseases such as osteoarthritis necessitates patient compliance, ensuring that the injected depot does not trigger local tissue inflammation and immune responses. A local drug delivery strategy that releases drug at a controlled rate while ensuring minimal tolerability issues at the injection site would be an appealing paradigm in intra-articular (IA) therapies. Herein, we report the formulation development and characterization of surface modified PLGA microparticles (MPs) through the surface integration of a cationic lipid, DOTAP (1,2-Dioleoyl-3-trimethylammonium propane). Following IA administration, these particles are able to interact with anionic synovial fluid glycosaminoglycans (GAGs) to form an in-situ surface coating in the knee joint, thereby reducing the depot-associated local inflammatory response. The formulated microparticles were about 10-40 µm in size range, with a +19 to +33 mV overall surface charge after DOTAP lipid surface integration. These particles showed preferential surface adhesion with endogenous anionic GAGs (e.g., hyaluronic acid) due to electrostatic interactions in vitro, and approximately 65% of the model drug triamcinolone acetonide (TCA) was released after 10 weeks in simulated synovial fluid. The uncoated and DOTAP-coated PLGA microparticles had no effect on mouse osteoblast MC3T3 cell viability and human macrophage inflammatory response. Further, DOTAP-coated particles showed a marginal decrease in pro-inflammatory cytokines in naïve rats following knee injection. Together, the results suggest that surface-modified PLGA particles may have promising potential as delivery carriers for long-acting injectables.

PEGylated recombinant human granulocyte colony stimulating factor (pegfilgrastim) is used clinically to reduce the incidence and duration of severe neutropenia in patients who have received chemotherapy treatment. Pegfilgrastim products are administered by subcutaneous injection. We herein report that solutions of pegfilgrastim originator product Neulasta®, of a biosimilar product candidate, and also of the pegfilgrastim originator formulation buffer, induced aggregate formation when mixed in vitro with human plasma, and formation of large membranous aggregated structures when mixed with human blood. Human donor variability in the plasma aggregation induced by pegfilgrastim products was observed. In all donors less aggregation occurred in plasma mixtures with the biosimilar pegfilgrastim product candidate compared to the originator products. Instantaneous aggregation of erythrocytes and formation of large membranous aggregated structures of erythrocytes occurred in mixtures of human blood with pegfilgrastim buffer or pegfilgrastim products. The formation of the large membranous aggregated structures likely involved fusion of erythrocyte membranes; erythrocyte membrane fusion events were observed. Pegfilgrastim proteins in the products accelerated the formation of irreversible erythrocyte aggregated structures. Pegfilgrastim originator formulation buffer (10 mM Na-acetate pH 4.0, 274 mM sorbitol, 0.004% polysorbate 20) was identified as the main driver of the plasma and erythrocyte aggregation. Lipoprotein aggregation at low pH in the presence of sorbitol and erythrocyte membrane fusion induced by the lipoprotein aggregates, are proposed as the main mechanisms for the formation of plasma and blood aggregates. Such aggregation phenomena may also occur during pegfilgrastim clinical use and may be related to known side effects and individual variability in the efficacy of pegfilgrastim therapy.

Eradication of Helicobacter pylori biofilm is crucial to the treatment of H. pylori infections, especially regarding the challenge of fast development of antibiotic resistance in H. pylori worldwide. Herein, a self-assembled berberine-loaded MEL-B nanomicelle (MEL-B NMs/BBR4) gastric delivery carrier was established to combat biofilm-induced H. pylori resistance in vivo. MEL-B NMs/BBR4 were tolerant to the stomach's acidic environment for the first 2 h and could quickly penetrate the mucus layer to reach the H. pylori colonization site. In addition, MEL-B NMs/BBR4 could damage the architecture of H. pylori biofilms, and simultaneously kill dispersed H. pylori cells by berberine and inhibit the formation of H. pylori biofilms. Significantly, MEL-B NMs/BBR4 decreased the H. pylori burden by 2 orders of magnitude and repaired the damaged gastric mucosal barrier while reducing the inflammatory response in vivo. In brief, this study provides a new strategy for using a fully natural nanodrug to effectively eradicate H. pylori biofilms in vivo.