Optimizing indomethacin-loaded chitosan nanoparticle size, encapsulation, and release using Box–Behnken experimental design

Exploring nalbuphine loaded chitosan nanoparticles for effective pain management through intranasal administration: a comparative study

BACKGROUND

Intranasal drug delivery shows potential for brain access via olfactory and trigeminal routes.

PURPOSE

This work aimed to ensure brain availability of nalbuphine via the nasal route.

METHOD

Chitosan based nanoparticles loaded with nalbuphine were successfully prepared using ionic gelation method and characterised.

RESULT

SEM results revealed that the nanoparticles were spherical in shape, with an average size of 192.4 ± 11.6 nm. Zeta potential and entrapment efficiency was found 32.8 mV and 88.43 ± 7.75%, respectively. The X-ray diffractometry and DSC results unravel a profound understanding on the physical and thermal characteristics. The in-vitro release of nalbuphine from the nanoparticles was biphasic, with an initial burst release followed by a slow-release profile. In-vitro cell study on HEK-293 cells and microscopic images of brain tissue confirmed the safety profile of formulation. In-vivo efficacy studies on animal confirmed the effectiveness of developed intranasal formulation as compared to the standard therapy. The in-vivo pharmacokinetic studies showed that the prepared nanoparticles were able to efficiently deliver nalbuphine to the brain in comparison to the other body organs. Gamma scintigraphy images showed retention of the drug in the brain. Furthermore, the efficacy studies confirmed that the nanoparticles were found significantly more effective than the marketed formulation in pain management.

Utilization of nanotechnology and experimental design in the development and optimization of a posaconazole‒calendula oil nanoemulgel for the treatment of mouth disorders

Introduction: Essential oil‒based nanoemulsions (NEs) are the subjects of extensive investigation due to their potential to address a variety of oral health issues. NEs are delivery systems that improve lipid medicine solubility and distribution to intended sites. The goal of the current study was to create and enhance a self-nanoemulsifying drug delivery paradigm based on calendula oil (CO) and decorated with chitosan (CS) that could deliver posaconazole (PSZ) for the treatment of gingivitis. Method: Employing a response-surface Box‒Behnken design, PSZ-CO-CS NEs were created with varying amounts of PSZ (10, 15, and 20 mg), percentages of CO (6%, 12%, and 18%), and percentages of CS (0.5%, 1.5%, and 2.5%). Results and conclusion: The optimized formulation resulted in a 22-mm bacterial growth suppression zone, 25-mm fungal growth inhibition zone, droplet sizes of 110 nm, and a viscosity of 750 centipoise (cP). Using the appropriate design, the ideal formulation was produced; it contained 20 mg of PSZ, 18% of CO, and 1.35% of CS. Furthermore, the optimal formulation had a more controlled drug release, larger inhibition zones of bacterial and fungal growth, and desirable rheologic properties. Additionally, the optimized formulation substantially lowered the ulcer index in rats when tested against other formulations. Thus, this investigation showed that PSZ-CO-CS NEs could provide efficient protection against microbially induced gingivitis.

Exploring the Ocular Absorption Pathway of Fasudil Hydrochloride towards Developing a Nanoparticulate Formulation with Improved Performance

Rho-kinase (ROCK) inhibitors represent a new category of anti-glaucoma medications. Among them, Fasudil hydrochloride, a selective ROCK inhibitor, has demonstrated promising outcomes in glaucoma treatment. It works by inhibiting the ROCK pathway, which plays a crucial role in regulating the trabecular meshwork and canal of Schlemm's aqueous humor outflow. This study aims to investigate the ocular absorption pathway of Fasudil hydrochloride and, subsequently, develop a nanoparticle-based delivery system for enhanced corneal absorption. Employing the ionic gelation method and statistical experimental design, the factors influencing chitosan nanoparticle (Cs NP) characteristics and performance were explored. Fasudil in vitro release and ex vivo permeation studies were performed, and Cs NP ocular tolerability and cytotoxicity on human lens epithelial cells were evaluated. Permeation studies on excised bovine eyes revealed significantly higher Fasudil permeation through the sclera compared to the cornea (370.0 μg/cm2 vs. 96.8 μg/cm2, respectively). The nanoparticle size (144.0 ± 15.6 nm to 835.9 ± 23.4 nm) and entrapment efficiency range achieved (17.2% to 41.4%) were predominantly influenced by chitosan quantity. Cs NPs showed a substantial improvement in the permeation of Fasudil via the cornea, along with slower release compared to the Fasudil aqueous solution. The results from the Hen's Egg Test Chorioallantoic Membrane (HET-CAM) and Bovine Corneal Opacity and Permeability (BCOP) tests indicated good conjunctival and corneal biocompatibility of the formulated chitosan nanoparticles, respectively. Lens epithelial cells displayed excellent tolerance to low concentrations of these nanoparticles (>94% cell viability). To the best of our knowledge, this is the first report on the ocular absorption pathway of topically applied Fasudil hydrochloride where the cornea has been identified as a potential barrier that could be overcome using Cs NPs.

Metronidazole loaded chitosan-phytic acid polyelectrolyte complex nanoparticles as mucoadhesive vaginal delivery system for bacterial vaginosis

Bacterial vaginosis (BV) is a recurring infection that is difficult to treat due to the limited bioavailability of antimicrobials. In this study, Metronidazole (MTZ)-loaded chitosan nanoparticles (MCSNP) were synthesized employing phytic acid (PA) as a crosslinking agent for treating bacterial vaginosis. The prepared MCSNPs were characterized for size, shape, surface charge, compatibility, cytotoxicity, biofilm inhibition, and in-vitro/in-vivo antimicrobial activities. Morphological examination revealed that nanoparticles generated from 0.535 % w/v chitosan and 0.112 % w/v PA were non-spherical, discontinuous, and irregular, with zeta potential ranging from 25.00 ± 0.45 to 39 ± 0.7. The results of DSC and XRD demonstrated no change in the physical state of the drug in the finished formulation. The optimized formulation demonstrates a cumulative drug release of about 98 ± 1.5 % within 8 h. Antimicrobial studies demonstrated that the optimized formulation had enhanced efficacy against acid-adapted BV pathogens, with a MIC value of 0.9 ± 0.1 μg/mL. Compared to the MTZ alone, the in-vivo antibacterial results of in the case of developed nanoparticles showed a four-fold reduction in bacterial count in female Swiss albino mice. Based on the experimental findings, it was concluded that MCSNPs, due to their excellent physiochemical and antibacterial properties, could serve as a potential topical alternative for treating BV.

Development and optimization of in-situ gel containing chitosan nanoparticles for possible nose-to-brain delivery of vinpocetine

Vinpocetine (VIN), a derivative of vincamine found in the vinca plant, widens blood vessels in the brain and has been shown to improve cognitive function, memory, and cerebrovascular disorders. Nevertheless, the clinical utility of VIN is constrained by factors such as low oral bioavailability owing to the first-pass metabolism that often demands frequent dosing of 3-4 tablets/day. In this regard, the present work aimed to develop VIN-loaded chitosan nanoparticles (VIN-CH-NPs) to surmount these limitations and in view to enhance delivery to the brain of VIN by minimizing systemic exposure. The chitosan (CH) nanoparticles (NP) were developed by ionotropic gelation technique employing tripolyphosphate (TPP) as a cross-linking agent. Employing Design of Experiments (DoE), the effect of CH and TPP concentrations and stirring speed were systematically optimized using Box Behnken design (BBD). The optimized batch of nanoparticles displayed a particle size, zeta potential, entrapment efficiency, and drug loading of 130.6 ± 8.38 nm, +40.81 ± 0.11 mV, 97.56 ± 0.04 %, and 61 ± 0.89 %, respectively. Fourier Transform Infrared Spectroscopy indicated the chemical integrity of the drug ruling out the interaction between the VIN and excipients used. DSC and PXRD data indicated that reduction of the crystallinity of VIN in the chitosan matrix. These VIN-CH-NPs manifested good stability, exhibiting an almost spherical morphology. To mitigate rapid mucociliary clearance upon intranasal administration, the optimized VIN-CH-NPs were incorporated into thermosensitive in situ gel (VIN-CHN-ISG). It was observed that the in-situ gel loaded with nanoparticles was opalescent with a pH level of 5.3 ± 0.38. It was also noted that the gelation temperature was 32 ± 0.89 °C, and the gelation time was approximately 15 s. The drug delivery to the brain through the nasal application of optimized VIN-NPs in situ gel was assessed in rats. The results indicated significant nasal application of the in-situ gel nearly doubled the Cmax (P < 0.05) and AUC0-t (P < 0.05) in the brain compared to oral administration. Nasal administration improved drug delivery to the brain by reducing systemic exposure to VIN. A histopathological study of the nasal mucosa revealed no irritation or toxicity, making it safe for nasal administration. These findings suggest that the developed NPs in-situ gel effectively targeted vinpocetine to the brain through the nasal pathway, providing a potential therapeutic strategy for managing Alzheimer's disease.

Optimization of cationic nanoparticles stabilized by poloxamer 188: A potential approach for improving the biological activity of Aloeperryi

Aloe perryi (AP) has gained considerable interest as a medicinal herb in various biological applications due to its rich phytochemical composition. However, the therapeutic benefits of AP could be potentiated by utilizing nanotechnology. Moreover, cationic solid lipid nanoparticles (CSLNs) possess remarkable characteristics that can greatly enrich a variety of biological uses. An optimization approach was used to achieve high-quality CSLNs to maximize the therapeutic efficacy of AP. Therefore, a factorial design was used to investigate the influence of various variables on the attributes of CSLNs quality. In this study, the factors under investigation were compritol 888 ATO (C-888, X1), poloxamer 188 (PL188, X2), and chitosan (CS, X3), which served as independent variables. The parameters measured as dependent variables included particle size (Y1), zeta potential (Y2), and encapsulation efficiency EE (Y3). The relationship among these variables was determined by Analysis of Variance (ANOVA) and response surface plots. The results revealed that PL188 played a significant role in reducing the particle size of CSLNS (ranging from 207 to 261 nm with 1 % PL188 to 167-229 nm with 3 % PL188). Conversely, an increase in the concentration of CS led to a rise in the particle size. The magnitude of positive zeta potential values was dependent on the increased concentration of CS. Moreover, the higher amounts of C-888 and PL188 improved the EE% of the CSLNs from 42 % to 86 %. Furthermore, a concentration-dependent antioxidant effect of the optimized AP-CSLNs was observed. The antioxidant activity of the optimized AP-CSLNs at 100 μg/mL was 75 % compared to 62 % and 60 % for AP-SLNs and AP solution, respectively. A similar pattern of improvement was also observed with antimicrobial, and anticancer activities of the optimized AP-CSLNs. These findings demonstrated the potential of AP-CSLNs as a carrier system, enhancing the biological activities of AP, opening new possibilities in herbal medicines.

Topical Sustained-Release Dexamethasone-Loaded Chitosan Nanoparticles: Assessment of Drug Delivery Efficiency in a Rabbit Model of Endotoxin-Induced Uveitis

Uveitis is an ocular illness that if not treated properly can lead to a total loss of vision. In this study, we evaluated the utility of HA-coated Dexamethasone-sodium-phosphate (DEX)-chitosan nanoparticles (CSNPs) coated with hyaluronic acid (HA) as a sustained ocular delivery vehicle for the treatment of endotoxin-induced-uveitis (EIU) in rabbits. The CSNPs were characterized for particle size, zeta potential, polydispersity, surface morphology, and physicochemical properties. Drug encapsulation, in vitro drug release, and transcorneal permeation were also evaluated. Finally, eye irritation, ocular pharmacokinetics, and pharmacodynamics were in vivo. The CSNPs ranged from 310.4 nm and 379.3 nm pre-(uncoated) and post-lyophilization (with HA-coated), respectively. The zeta potentials were +32 mV (uncoated) and -5 mV (HA-uncoated), while polydispersity was 0.178-0.427. Drug encapsulation and loading in the CSNPs were 73.56% and 6.94% (uncoated) and 71.07% and 5.54% (HA-coated), respectively. The in vitro DEX release over 12 h was 77.1% from the HA-coated and 74.2% from the uncoated NPs. The physicochemical properties of the CSNPs were stable over a 3-month period when stored at 25 °C. Around a 10-fold increased transcorneal-flux and permeability of DEX was found with HA-CSNPs compared to the DEX-aqueous solution (DEX-AqS), and the eye-irritation experiment indicated its ocular safety. After the ocular application of the CSNPs, DEX was detected in the aqueous humor (AH) till 24 h. The area under the concentrations curve (AUC0-24h) for DEX from the CSNPs was 1.87-fold (uncoated) and 2.36-fold (HA-coated) higher than DEX-AqS. The half-life (t1/2) of DEX from the uncoated and HA-coated NPs was 2.49-and 3.36-fold higher, and the ocular MRT0-inf was 2.47- and 3.15-fold greater, than that of DEX-AqS, respectively. The EIU rabbit model showed increased levels of MPO, TNF-α, and IL-6 in AH. Topical DEX-loaded CSNPs reduced MPO, TNF-α, and IL-6 levels as well as inhibited NF-κB expression. Our findings demonstrate that the DEX-CSNPs platform has improved the delivery properties and, hence, the promising anti-inflammatory effects on EIU in rabbits.

Electrospun/3D-Printed Bicomponent Scaffold Co-Loaded with a Prodrug and a Drug with Antibacterial and Immunomodulatory Properties

This work reports the construction of a bicomponent scaffold co-loaded with both a prodrug and a drug (BiFp@Ht) as an efficient platform for wound dressing, by combining the electrospinning and 3D-printing technologies. The outer component consisted of a chitosan/polyethylene oxide-electrospun membrane loaded with the indomethacin-polyethylene glycol-indomethacin prodrug (Fp) and served as a support for printing the inner component, a gelatin methacryloyl/sodium alginate hydrogel loaded with tetracycline hydrochloride (Ht). The different architectural characteristics of the electrospun and 3D-printed layers were very well highlighted in a morphological analysis performed by Scanning Electron Microscopy (SEM). In vitro release profile studies demonstrated that both Fp and Ht layers were capable to release the loaded therapeutics in a controlled and sustained manner. According to a quantitative in vitro biological assessment, the bicomponent BiFp@Ht scaffold showed a good biocompatibility and no cytotoxic effect on HeLa cell cultures, while the highest proliferation level was noted in the case of HeLa cells seeded onto an Fp nanofibrous membrane. Furthermore, the BiFp@Ht scaffold presented an excellent antimicrobial activity against the E. coli and S. aureus bacterial strains, along with promising anti-inflammatory and proangiogenic activities, proving its potential to be used for wound dressing.

Topical Application of Linezolid-Loaded Chitosan Nanoparticles for the Treatment of Eye Infections

Linezolid (LZ) loaded chitosan-nanoparticles (CSNPs) was developed by the ionic-gelation method using Tripolyphosphate-sodium as a crosslinker for topical application for the treatment of bacterial eye infections. Particles were characterized by Zeta-Sizer (Malvern Nano-series). TEM was used for structural morphology. Encapsulation and drug loading were estimated by measuring the unencapsulated drug. In-vitro drug release in STF (pH 7) was performed through a dialysis membrane. Storage stability of LZ-CSNPs was checked at 25 °C and 40 °C for six months. The antimicrobial potency of NPs was evaluated on different Gram-positive strains. Ocular irritation and pharmacokinetic studies were completed in rabbits. Ex-vivo transcorneal permeation of the drug was determined through the rabbit cornea. Ionic interaction among the oppositely charged functional groups of CS and TPP generated the CSNPs. The weight ratio at 3:1, wt/wt (CS/TPP) with 21.7 mg of LZ produced optimal NPs (213.7 nm with 0.387 of PDI and +23.1 mV of ZP) with 71% and 11.2% encapsulation and drug loading, respectively. Around 76.7% of LZ was released from LZ-AqS within 1 h, while 79.8% of LZ was released from CSNPs at 12 h and 90% at 24 h. The sustained drug release property of CSNPS was evaluated by applying kinetic models. The linearity in the release profile suggested that the release of LZ from CSNPs followed the Higuchi-Matrix model. LZ-CSNPs have shown 1.4 to 1.6-times improved antibacterial activity against the used bacterial strains. The LZ-CSNPs were "minimally-irritating" to rabbit eyes and exhibited 4.4-times increased transcorneal permeation of LZ than from LZ-AqS. Around 3-, 1.2- and 3.1-times improved T_max, C_max, and AUC_{0-24 h}, respectively were found for LZ-CSNPs during the ocular pharmacokinetic study. AqS has shown 3.1-times faster clearance of LZ. Conclusively, LZ-CSNPs could offer a better alternative for the prolonged delivery of LZ for the treatment of bacterial infections in the eyes.

Optimization and Appraisal of Chitosan-Grafted PLGA Nanoparticles for Boosting Pharmacokinetic and Pharmacodynamic Effect of Duloxetine HCl Using Box-Benkhen Design

Duloxetine HCl (DXH) is a psychiatric medicine employed for treating major depressive disorder. Nonetheless, its low water solubility, high first-pass metabolism, and acid instability diminish the absolute oral bioavailability to 40%, thus necessitating frequent administration. Therefore, the aim of the current study was to formulate DXH as nasal chitosan-grafted polymeric nanoparticles to improve its pharmacokinetic and pharmacodynamic properties. Applying the Box-Behnken design, DXH loaded PLGA-Chitosan nanoparticles (DXH-PLGA-CS-NPs) were fabricated and optimized using polylactide-co-glycolic acid (PLGA), chitosan (CS), and polyvinyl alcohol (PVA) as the independent factors. Particle size, entrapment efficiency, release percent, and cumulative amount permeated after 24 h of DXH-PLGA-CS-NPs (dependent variables) were evaluated. The in-vivo biodistribution and pharmacodynamic studies were done in male Wistar rats. The optimized DXH-PLGA-CS-NPs had a vesicle size of 122.11 nm and EE% of 66.95 with 77.65% release and Q₂₄ of 555.34 (µg/cm²). Ex-vivo permeation study revealed 4-folds increase in DXH permeation from DXH-PLGA-CS-NPs after 24 h compared to DXH solution. Intranasal administration of optimized DXH-PLGA-CS-NPs resulted in significantly higher (p < 0.05) C_max, AUC_total, t_1/2, and MRT in rat brain and plasma than oral DXH solution. Pharmacodynamics investigation revealed that intranasally exploited optimal DXH-PLGA-CS-NPs could be deemed a fruitful horizon for DXH as a treatment for depression.

Novel Mucoadhesive Wafers for Treating Local Vaginal Infections

Current vaginal formulations, such as gels and pessaries, have limitations, including poor retention. Therefore, the use of mucoadhesive formulations that adhere to the vaginal wall would allow prolonged retention and controlled drug release while reducing the required dose and the potential toxicity associated with high drug loading. The aim of the current research was to develop, characterize, and optimize freeze-dried wafers loaded with metronidazole (MTz) to treat vaginal bacterial infections. Blank (BLK) composite wafers comprising carrageenan (CARR) and sodium alginate (SA) were initially formulated; however, due to poor physico-chemical properties, Carbopol (CARB), hydroxypropylmethylcellulose (HPMC), and polyethylene glycol 200 (PEG) were included. The MTz-loaded formulations were obtained by loading optimized composite CARB:CARR- or CARB:SA-based gels (modified with HPMC and/or PEG) with 0.75% of MTz prior to freeze-drying. The physico-chemical properties were investigated using texture analysis (resistance to compressive deformation and adhesion), scanning electron microscopy (SEM), X-ray diffractometry (XRD), and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. Functional properties were investigated by examining the swelling, porosity, drug release, and in vitro antimicrobial activity using E. coli as a model infection-causative agent. The results showed that HPMC and PEG generally improved the wafer's appearance, with smoother surfaces for easy insertion. From the physico-chemical characterization studies, only two composite wafers prepared from 8% CARB:SA 1:4 and 8% CARB:SA 1:9 gels were deemed optimal and loaded with MTz. Both formulations showed sustained drug release and achieved almost 100% cumulative release within 72 h in simulated vaginal fluid. The data obtained from the drug dissolution (release) experiments were fitted to various mathematical equations and showed the highest correlation coefficient with the Higuchi equation, suggesting a drug release based on diffusion from a swollen matrix; this was confirmed by the Korsmeyer-Peppas equation. The released MTz inhibited the growth of the E. coli used as a model bacterial organism.

Preparation, Characterization, In Vitro Release, and Antibacterial Activity of Oregano Essential Oil Chitosan Nanoparticles

Essential oils have unique functional properties, but their environmental sensitivity and poor water solubility limit their applications. Therefore, we encapsulated oregano essential oil (OEO) in chitosan nanoparticles (CSNPs) and used tripolyphosphate (TPP) as a cross-linking agent to produce oregano essential oil chitosan nanoparticles (OEO-CSNPs). The optimized conditions obtained using the Box-Behnken design were: a chitosan concentration of 1.63 mg/mL, TPP concentration of 1.27 mg/mL, and OEO concentration of 0.30%. The OEO-CSNPs had a particle size of 182.77 ± 4.83 nm, a polydispersity index (PDI) of 0.26 ± 0.01, a zeta potential of 40.53 ± 0.86 mV, and an encapsulation efficiency of 92.90%. The success of OEO encapsulation was confirmed by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The scanning electron microscope (SEM) analysis showed that the OEO-CSNPs had a regular distribution and spherical shape. The in vitro release profile at pH = 7.4 showed an initial burst release followed by a sustained release of OEO. The antibacterial activity of OEO before and after encapsulation was measured using the agar disk diffusion method. In conclusion, OEO can be used as an antibacterial agent in future food processing and packaging applications because of its high biological activity and excellent stability when encapsulated.

The Influence of Drugs Solubilities and Chitosan-TPP Formulation Parameters on the Mean Hydrodynamic Diameters and Drugs Entrapment Efficiencies into Chitosan-TPP Nanoparticles

Chitosan is a natural, biocompatible polymer. The aim of this work was to study the influence of drug solubility in 2% v/v acetic acid, formulation parameters, on mean hydrodynamic (MHD) diameters and drug entrapment efficiencies (% EE) into chitosan-TPP nanoparticles (NPs). Drugs of different aqueous solubilities with nearly similar molecular weights were chosen and admixed at several concentrations in 2% acetic acid at different chitosan concentrations and at fixed chitosan to TPP concentrations/volumes ratios. The NPs were freeze-dried, and the supernatants were utilized to determine % EE. Theophylline- and antipyrine-loaded NPs showed the best short-term physical stability in terms of MHD diameters. Antipyrine-loaded NPs possessed the larger MHD diameters, while vitamin C-loaded NPs showed the smallest ones. The relationships between the ratio of drug concentration relative to their solubilities in acetic acid were almost linear for antipyrine and vitamin C-loaded NPs when plotted against and the MHD diameters of NPs, and linear for antipyrine- and theophylline-loaded NPs when plotted against % EE with antipyrine NPs possessing the highest % EE. However, vitamin C- and propylthiouracil-loaded NPs exhibited curvilinear patterns with comparatively lower % EE. The concentration of chitosan, drug solubility in dispersion medium, and the ratio of the concentration of admixed drug relative to its solubility in dispersion medium were found critical in determining % EE and MHD diameters of NPs. It was evident that drugs with extremely low or high solubilities in dispersion medium resulted in low % EE when admixed at both low and high concentrations.

Development of a Curcumin-Loaded Lecithin/Chitosan Nanoparticle Utilizing a Box-Behnken Design of Experiment: Formulation Design and Influence of Process Parameters

Curcumin (CUR) has impressive pharmacologic properties, including cardioprotective, neuroprotective, antimicrobial, and anticancer activity. However, the pharmaceutical application of CUR is limited due to its poor aqueous solubility and low bioavailability. The development of novel formulations has attracted considerable attention to the idea of applying nanobiotechnology to improve the therapeutic efficacy of these challenging compounds. In this study, CUR-loaded lecithin−chitosan nanoparticles (CUR/LCSNPs) were developed and optimized by the concentration of chitosan, lecithin, and stirring speed by a 3-factorial Box-Behnken statistical design, resulting in an optimal concentration of chitosan (A) and lecithin (B) with a 1200 rpm stirring speed (C), with applied constraints of minimal average particle size (Y1), optimal zeta potential (Y2), and maximum entrapment efficiency (%EE) (Y3). The mean particle size of the checkpoint formulation ranged from 136.44 ± 1.74 nm to 267.94 ± 3.72, with a zeta potential of 18.5 ± 1.39 mV to 36.8 ± 3.24 mV and %EE of 69.84 ± 1.51% to 78.50 ± 2.11%. The mean particle size, zeta potential, %EE, and % cumulative drug release from the optimized formulation were 138.43 ± 2.09 nm, +18.98 ± 0.72 mV, 77.39 ± 1.70%, and 86.18 ± 1.5%, respectively. In vitro drug release followed the Korsmeyer−Peppas model with Fickian diffusion (n < 0.45). The optimized technique has proven successful, resulting in a nanoformulation that can be used for the high loading and controlled release of lipophilic drugs.

Development and Optimization of Ciprofloxacin HCl-Loaded Chitosan Nanoparticles Using Box–Behnken Experimental Design

Various chitosan (CS)-based nanoparticles (CS-NPs) of ciprofloxacin hydrochloride (CHCl) have been investigated for therapeutic delivery and to enhance antimicrobial efficacy. However, the Box–Behnken design (BBD)-supported statistical optimization of NPs of CHCl has not been performed in the literature. As a result, the goal of this study was to look into the key interactions and quadratic impacts of formulation variables on the performance of CHCl-CS-NPs in a systematic way. To optimize CHCl-loaded CS-NPs generated by the ionic gelation process, the response surface methodology (RSM) was used. The BBD was used with three factors on three levels and three replicas at the central point. Tripolyphosphate, CS concentrations, and ultrasonication energy were chosen as independent variables after preliminary screening. Particle size (PS), polydispersity index (PDI), zeta potential (ZP), encapsulation efficiency (EE), and in vitro release were the dependent factors (responses). Prepared NPs were found in the PS range of 198–304 nm with a ZP of 27–42 mV. EE and drug release were in the range of 23–45% and 36–61%, respectively. All of the responses were optimized at the same time using a desirability function based on Design Expert® modeling and a desirability factor of 95%. The minimum inhibitory concentration (MIC) of the improved formula against two bacterial strains, Pseudomonas aeruginosa and Staphylococcus aureus, was determined. The MIC of the optimized NPs was found to be decreased 4-fold compared with pure CHCl. The predicted and observed values for the optimized formulation were nearly identical. The BBD aided in a better understanding of the intrinsic relationship between formulation variables and responses, as well as the optimization of CHCl-loaded CS-NPs in a time- and labor-efficient manner.

Effect of Solvents, Stabilizers and the Concentration of Stabilizers on the Physical Properties of Poly(d,l-lactide-co-glycolide) Nanoparticles: Encapsulation, In Vitro Release of Indomethacin and Cytotoxicity against HepG2-Cell

A biocompatible, biodegradable and FDA-approved polymer [Poly lactic-co-glycolic acid (PLGA)] was used to prepare the nanoparticles (NPs) to observe the effect of solvents, stabilizers and their concentrations on the physical properties of the PLGA-NPs, following the encapsulation and in vitro release of Indomethacin (IND). PLGA-NPs were prepared by the single-emulsion solvent evaporation technique using dichloromethane (DCM)/chloroform as the organic phase with Polyvinyl-alcohol (PVA)/Polyvinylpyrrolidone (PVP) as stabilizers to encapsulate IND. The effects of different proportions of PVA/PVP with DCM/chloroform on the physiochemical properties (particle size, the polydispersity index, the zeta potential by Malvern Zetasizer and morphology by SEM) of the NPs were investigated. DSC was used to check the physical state, the possible complexation of PLGA with stabilizer(s) and the crystallinity of the encapsulated drug. Stabilizers at all concentrations produced spherical, regular-shaped, smooth-surfaced discrete NPs. Average size of 273.2–563.9 nm was obtained when PVA (stabilizer) with DCM, whereas it ranged from 317.6 to 588.1 nm with chloroform. The particle size was 273.2–563.9 nm when PVP was the stabilizer with DCM, while it was 381.4–466.6 nm with chloroform. The zeta potentials of PVA-stabilized NPs were low and negative (−0.62 mV) while they were comparatively higher and positive for PVP-stabilized NPs (+17.73 mV). Finally, drug-loaded optimal NPs were composed of PLGA (40 mg) and IND (4 mg) in 1 mL DCM/chloroform with PVA/PVP (1–3%), which resulted in sufficient encapsulation (54.94–74.86%) and drug loading (4.99–6.81%). No endothermic peak of PVA/PVP appeared in the optimized formulation, which indicated the amorphous state of IND in the core of the PLGA-NPs. The in vitro release study indicated a sustained release of IND (32.83–52.16%) from the PLGA-NPs till 72 h and primarily followed the Higuchi matrix release kinetics followed by Korsmeyer–Peppas models. The cell proliferation assay clearly established that the organic solvents used to prepare PLGA-NPs had evaporated. The PLGA-NPs did not show any particular toxicity in the HepG2 cells within the dose range of IND (250–500 µg/mL) and at an equivalent concentration of PLGA-NPs (3571.4–7142.7 µg/mL). The cytotoxicity of the hepatotoxic drug (IND) was reduced by its encapsulation into PLGA-NPs. The outcomes of this investigation could be implemented to prepare PLGA-NPs of acceptable properties for the encapsulation of low/high molecular weight drugs. It would be useful for further in vitro and in vivo applications to use this delivery system.

Development and Evaluation of Chitosan Nanoparticles for Ocular Delivery of Tedizolid Phosphate

This study investigates the development of topically applied non-invasive chitosan-nanoparticles (CSNPs) for ocular delivery of tedizolid phosphate (TZP) for the treatment of MRSA-related ocular and orbital infections. An ionic-gelation method was used to prepare TZP-encapsulated CSNPs using tripolyphosphate-sodium (TPP) as cross-linker. Particle characterization was performed by the DLS technique (Zeta-Sizer), structural morphology was observed by SEM. The drug encapsulation and loading were determined by the indirect method. In-vitro release was conducted through dialysis bags in simulated tear fluid (pH 7) with 0.25% Tween-80. Physicochemical characterizations were performed for ocular suitability of CSNPS. An antimicrobial assay was conducted on different strains of Gram-positive bacteria. Eye-irritation from CSNPs was checked in rabbits. Transcorneal flux and apparent permeability of TZP from CSNPs was estimated through excised rabbit cornea. Ionic interaction between the anionic and cationic functional groups of TPP and CS, respectively, resulted in the formation of CSNPs at varying weight ratios of CS/TPP with magnetic stirring (700 rpm) for 4 h. The CS/TPP weight ratio of 3.11:1 with 10 mg of TZP resulted in optimal-sized CSNPs (129.13 nm) with high encapsulation (82%) and better drug loading (7%). Release profiles indicated 82% of the drug was released from the TZP aqueous suspension (TZP-AqS) within 1 h, while it took 12 h from F2 to release 78% of the drug. Sustained release of TZP from F2 was confirmed by applying different release kinetics models. Linearity in the profile (suggested by Higuchi’s model) indicated the sustained release property CSNPs. F2 has shown significantly increased (p < 0.05) antibacterial activity against some Gram-positive strains including one MRSA strain (SA-6538). F2 exhibited a 2.4-fold increased transcorneal flux and apparent permeation of TZP as compared to TZP-AqS, indicating the better corneal retention. No sign or symptoms of discomfort in the rabbits’ eyes were noted during the irritation test with F2 and blank CSNPs, indicating the non-irritant property of the TZP-CSNPs. Thus, the TZP-loaded CSNPs have strong potential for topical use in the treatment of ocular MRSA infections and related inflammatory conditions.

Nanoencapsulated Extract of a Red Seaweed (Rhodophyta) Species as a Promising Source of Natural Antioxidants

Marine seaweed species represent an important source of bioactive compounds possessing antioxidant activity. This study aimed at evaluating the antioxidant capacity of the Jania rubens algal extract by means of two antioxidant assays, i.e., 2,2-diphenyl-1-picrylhydrazyl and ferric-reducing antioxidant power. The seaweeds' total phenolic and flavonoid contents were also assayed as markers of antioxidant activity. To identify active agents responsible for the antioxidant activity, gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry were used for comprehensive metabolites characterization. To enhance the Jania rubens efficacy, the extract was nanoencapsulated using an ionic gelation method by means of high-pressure homogenization. The optimum nanoformulation had a particle size of 161 nm, a ζ potential of 31.2 mV, a polydispersity index of 0.211, and entrapment efficiency of 99.7%. The in vitro phytochemicals' release profiles of Jania rubens chitosan nanoparticles in comparison to the concentration of the raw algal extract were studied by the dialysis bag diffusion method revealing that the extract was released in a controlled pattern. The results indicated the potential advantages of the encapsulated Jania rubens extract, with its potent antioxidant activity, for use in different applications where sustained release is useful.

Use of jackfruit leaf (Artocarpus heterophyllus L.) protein hydrolysates as a stabilizer of the nanoemulsions loaded with extract-rich in pentacyclic triterpenes obtained from Coccoloba uvifera L. leaf

This study aimed to evaluate the encapsulating potential of a jackfruit leaf protein hydrolysate, through obtaining pentacyclic triterpenes-rich extract loaded nanoemulsion. Response surface methodology (RSM) was used to optimize the conditions to obtain an optimal nanoemulsion (NE-Opt). The effect of protein hydrolysate concentration (0.5-2%), oil loaded with extract (2.5-7.5%), and ultrasound time (5-15 min) on the polydispersity index (PDI) and droplet size of the emulsion (D[3,2] and D[4,3]) was evaluated. RSM revealed that 1.25% protein hydrolysate, 2.5% oil, and ultrasound time of 15 min produced the NE-Opt with the lowest PDI (0.85), D[3,2] (330 nm), and D[4,3] (360 nm). Encapsulation efficiency and extract loading of the NE-Opt was of 40.15 ± 1.46 and 18.03 ± 2.78% respectively. The NE-Opt was relatively stable during storage (at 4 and 25 °C), pH, temperature, and ionic strength. Then, the protein hydrolysate could be used as an alternative to conventional emulsifiers.

Preparation and optimization of controlled release nanoparticles containing cefixime using Central Composite design: An attempt to enrich its antimicrobial activity

BACKGROUND

Due to the increased resistance against existing antibiotics, research is essential to discover new and alternative ways to control infections induced by resistant pathogens.

OBJECTIVE

The goal of the current scrutinization was to enrich the dissolution rate and antibacterial property of cefixime (CEF) orally.

METHODS

To achieve the desired results, chitosan nanoparticles (NPs) containing CEF were fabricated using the ionic gelation method. Central Composite design has been applied to get the optimal formulation for the delivery of CEF. The effect of three variables such as the concentration of chitosan, tripolyphosphate, and tween 80 on the characteristics of NPs was evaluated.

RESULTS

The optimized NPs were a relatively monodispersed size distribution with an average diameter of 193 nm and a zeta potential of about 11 mV. The scanning tunneling microscope confirmed the size of NPs. The surface morphology of NPs was observed by scanning electron microscopy. The calorimetric analysis indicated the amorphous state of cefixime in the formulation. The dissolution rate of NPs in aqueous media was acceptable and the model of release kinetic for CEF from NPs followed the Peppas model. The potency of CEF in NPs against various types of bacteria was hopefully efficient. The ex- vivo release study demonstrated higher penetration of NPs from the rat intestine compared to free drug. The cell culture study showed the safety of the optimized formulation.

CONCLUSION

It was concluded that CLN could be considered as a prospering system for the controlled delivery of CEF with advantaging its antibacterial effectiveness.

Protective Action of Jania rubens Nanoencapsulated Algal Extract in Controlling Vegetable Oils' Rancidity

The development of natural antioxidants that can mitigate oil oxidation is on the rise. Several antioxidants have been developed from natural terrestrial plants, with less emphasis on marine algae. Rancidity is a major degradative reaction limiting the shelf-life and deteriorating the quality of vegetable oils. The goal of this study was to evaluate the ability of the Jania rubens' (J. rubens) seaweed extract encapsulated by chitosan/tripolyphosphate in retarding lipids' oxidation in vegetable oils. To improve the J. rubens efficacy, the extract was nanoencapsulated using the ionic gelation method. A Box-Behnken design was applied for the optimization of the formulation variables (chitosan/tripolyphosphate amounts, homogenization time, and homogenization speed). The optimum nanoformulation was characterized by transmission electron microscopy. It had a particle size of 161 nm, zeta potential of 31.2 mV, polydispersity index of 0.211, and entrapment efficiency of 99.7%. The ability of the optimum formula to extend the shelf-life of vegetable oils was based on peroxide value and thiobarbituric acid assays. In addition, headspace solid-phase microextraction was applied to detect the oils' volatiles as secondary markers of rancidity. The results revealed that the nanoencapsulated algal extract considerably reduced the rate of oils' oxidation and that its activity was comparable to that of a widely used synthetic antioxidant.

Chitosan Nanocarrier Entrapping Hydrophilic Drugs as Advanced Polymeric System for Dual Pharmaceutical and Cosmeceutical Application: A Comprehensive Analysis Using Box-Behnken Design

The objective of the present research is to propose chitosan as a nanocarrier for caffeine—a commonly used drug in combating cellulite. Being a hydrophilic drug, caffeine suffers from insufficient topical penetration upon application on the skin. Chitosan nanoparticles loaded with caffeine were prepared via the ionic gelation technique and optimized according to a Box–Behnken design. The effect of (A) chitosan concentration, (B) chitosan solution pH, and (C) chitosan to sodium tripolyphosphate mass ratio on (Y1) entrapment efficiency percent, (Y2) particle size, (Y3) polydispersity index, and (Y4) zeta potential were studied. Subsequently, the desired constraints on responses were applied, and validation of the optimization procedure was confirmed by the parameters exhibited by the optimal formulation. A caffeine entrapment efficiency percent of 17.25 ± 1.48%, a particle size of 173.03 ± 4.32 nm, a polydispersity index of 0.278 ± 0.01, and a surface charge of 41.7 ± 3.0 mV were attained. Microscopical evaluation using transmission electron microscope revealed a typical spherical nature of the nanoparticles arranged in a network with a further confirmation of the formation of particles in the nano range. The results proved the successful implementation of the Box–Behnken design for optimization of chitosan-based nanoparticles in the field of advanced polymeric systems for pharmaceutical and cosmeceutical applications.

Encapsulation of the Natural Product Tyrosol in Carbohydrate Nanosystems and Study of Their Binding with ctDNA

Tyrosol, a natural product present in olive oil and white wine, possesses a wide range of bioactivity. The aim of this study was to optimize the preparation of nanosystems encapsulating tyrosol in carbohydrate matrices and the investigation of their ability to bind with DNA. The first encapsulation matrix of choice was chitosan using the ionic gelation method. The second matrix was β-cyclodextrin (βCD) using the kneading method. Coating of the tyrosol-βCD ICs with chitosan resulted in a third nanosystem with very interesting properties. Optimal preparation parameters of each nanosystem were obtained through two three-factor, three-level Box-Behnken experimental designs and statistical analysis of the results. Thereafter, the nanoparticles were evaluated for their physical and thermal characteristics using several techniques (DLS, NMR, FT-IR, DSC, TGA). The study was completed with the investigation of the impact of the encapsulation on the ability of tyrosol to bind to calf thymus DNA. The results revealed that tyrosol and all the studied systems bind to the minor groove of ctDNA. Tyrosol interacts with ctDNA via hydrogen bond formation, as predicted via molecular modeling studies and corroborated by the experiments. The tyrosol-chitosan nanosystem does not show any binding to ctDNA whereas the βCD inclusion complex shows analogous interaction with that of free tyrosol.

Multifunctional Natural Polymer Nanoparticles as Antifibrotic Gene Carriers for CKD Therapy

BACKGROUND

Progressive fibrosis is the underlying pathophysiological process of CKD, and targeted prevention or reversal of the profibrotic cell phenotype is an important goal in developing therapeutics for CKD. Nanoparticles offer new ways to deliver antifibrotic therapies to damaged tissues and resident cells to limit manifestation of the profibrotic phenotype.

METHODS

We focused on delivering plasmid DNA expressing bone morphogenetic protein 7 (BMP7) or hepatocyte growth factor (HGF)-NK1 (HGF/NK1) by encapsulation within chitosan nanoparticles coated with hyaluronan, to safely administer multifunctional nanoparticles containing the plasmid DNA to the kidneys for localized and sustained expression of antifibrotic factors. We characterized and evaluated nanoparticles in vitro for biocompatibility and antifibrotic function. To assess antifibrotic activity in vivo, we used noninvasive delivery to unilateral ureteral obstruction mouse models of CKD.

RESULTS

Synthesis of hyaluronan-coated chitosan nanoparticles containing plasmid DNA expressing either BMP7 or NGF/NKI resulted in consistently sized nanoparticles, which-following endocytosis driven by CD44⁺ cells-promoted cellular growth and inhibited fibrotic gene expression in vitro. Intravenous tail injection of these nanoparticles resulted in approximately 40%-45% of gene uptake in kidneys in vivo. The nanoparticles attenuated the development of fibrosis and rescued renal function in unilateral ureteral obstruction mouse models of CKD. Gene delivery of BMP7 reversed the progression of fibrosis and regenerated tubules, whereas delivery of HGF/NK1 halted CKD progression by eliminating collagen fiber deposition.

CONCLUSIONS

Nanoparticle delivery of HGF/NK1 conveyed potent antifibrotic and proregenerative effects. Overall, this research provided the proof of concept on which to base future investigations for enhanced targeting and transfection of therapeutic genes to kidney tissues, and an avenue toward treatment of CKD.

Chitosan and its Derivatives for Ocular Delivery Formulations: Recent Advances and Developments

Chitosan (CS) is a hemi-synthetic cationic linear polysaccharide produced by the deacetylation of chitin. CS is non-toxic, highly biocompatible, and biodegradable, and it has a low immunogenicity. Additionally, CS has inherent antibacterial properties and a mucoadhesive character and can disrupt epithelial tight junctions, thus acting as a permeability enhancer. As such, CS and its derivatives are well-suited for the challenging field of ocular drug delivery. In the present review article, we will discuss the properties of CS that contribute to its successful application in ocular delivery before reviewing the latest advances in the use of CS for the development of novel ophthalmic delivery systems. Colloidal nanocarriers (nanoparticles, micelles, liposomes) will be presented, followed by CS gels and lenses and ocular inserts. Finally, instances of CS coatings, aiming at conferring mucoadhesiveness to other matrixes, will be presented.

Development of Darunavir proliposome powder for oral delivery by using Box-Bhenken design

The aim of this study is to develop Darunavir (DRV) proliposome powder for oral delivery. Darunavir-loaded oral proliposome powder (OPP) was prepared by a solvent evaporation technique with varying independent variables at three different levels. Based on different levels, proliposome powder formulation was optimized by using Box-Behnken design. The formulations were analyzed for its size distribution, entrapment efficiency, and surface morphology. Optimized proliposome batch A was evaluated for physical parameter, morphological parameters, entrapment efficiency, followed by in vitro, ex vivo, and in vivo studies. Oral proliposome powder showed good micromeritic properties with angle of repose was less than 30°, Carr's index and Hausner's ratio were also less than 21 and 1.25, respectively. The mean size of the vesicles was in the range of 180-290 nm. The assay and entrapment efficiency of pro-liposome powder formulations were 79.00 ± 0.2 and 93.46 ± 0.2%, respectively. In vitro release of DRV proliposome powder was 78.17 ± 0.1% after 24 h which shows good release from the vesicle of proliposome. Ex vivo permeation study shows 58.11% enhancement which shows good permeation. The optimize batch A of proliposome powder indicated 50% enhancement in the relative bioavailability as compared to the DRV suspension. The results showed that proliposome powder containing DRV can efficiently deliver in to the blood stream. This drug delivery system has been designed as a novel platform for potential oral delivery of drugs having poor water solubility and high first-pass metabolism.

Fabrication of Fine Puerarin Nanocrystals by Box-Behnken Design to Enhance Intestinal Absorption

Puerarin is widely used as a therapeutic agent to cardiovascular diseases in clinics in China through intravenous administration, which could elicit adverse drug reactions caused by cosolvents, hindering its application in clinics. Therefore, the development of oral dosage is urgently needed. In our previous studies, we proved that the bioavailability of puerarin increased as particle sizes of nanocrystals decreased; however, we have not optimized the best process parameters for nanocrystals. In this study, we aim to fabricate fine nanocrystals (with smallest particle size) by Box-Behnken design and study the intestinal permeability of puerarin and its nanocrystals via employing everted gut sac model and in situ perfusion model. The results showed that the Box-Behnken design could be used to optimize the producing parameters of puerarin nanocrystals, and the particle sizes of fine nanocrystals were about 20 nm. Results of everted gut sacs showed that the polyvinylpyrrolidone (PVP) and verapamil had no influence on the absorption of puerarin and nanocrystals, and the nanocrystals could increase the P_app of puerarin for 2.2-, 2.9-, and 2.9-folds, respectively, in duodenum, jejunum, and ileum. Enhanced Ka and Peff were observed on the nanocrystal group, compared with puerarin, and PVP and verapamil had no influence on the absorption of nanocrystals, while the absorption of puerarin was influenced by P-gp efflux. Combining the results mentioned above, we can conclude that the Box-Behnken design benefits the optimization for preparation of nanocrystals, and the nanocrystals could enhance the intestinal absorption of puerarin by enhanced permeability and inhibited P-gp efflux.

Repurposing Itraconazole Loaded PLGA Nanoparticles for Improved Antitumor Efficacy in Non-Small Cell Lung Cancers

Itraconazole (ITR) is a broad-spectrum antifungal drug, which has been shown to possess some promising anticancer, anti-proliferative, and anti-angiogenic properties in some cancers, such as cancers of the lung, breast, and skin. However, ITR has some drawbacks, such as poor water solubility, which hinder its use as a therapeutic agent. Therefore, in the present study, we developed and characterized chitosan-coated PLGA nanoparticles of itraconazole and studied their anticancer activities in H1299 lung cancer cells. The prepared ITR nanoparticles showed a small particle size, narrow poly dispersity index (PDI), positive zeta potential, and a controlled drug release profile. The cytotoxicity of ITR nanoparticles (NPs) on H1299 cancer cells after 24 h of exposure was greater than that of the ITR solution. Apoptosis of cancer cells exposed to ITR nanoparticles was also enhanced in comparison with the ITR solution. At the molecular level, ITR NPs were more effective than ITR solution in inducing pro-apoptotic Bax and p53 while reducing anti-apoptotic Bcl2 protein expression. ITR NPs were more effective than ITR solution in arresting cells both at the G0/G1 as well as G2/M phases of the cell cycle. Hence, repurposing itraconazole by encapsulation into PLGA NPs with chitosan coating is a potentially promising approach to treat lung cancers.

Implementation of two different experimental designs for screening and optimization of process parameters for metformin-loaded carboxymethyl chitosan formulation

Metformin (MET) was effectively encapsulated into O-carboxymethyl chitosan (O-CMC) polymeric formulation using an experimental design method. Six factors Plackett-Burman (PB) design was utilized to find the significant process parameters. Linear equations used to study the effect of each process parameters on particle size (PS), encapsulation efficiency (EE), and zeta potential (ZP) and the most influential three factors decided for further optimization. Optimization was carried out by implementing three-factor three-level Box-Behnken (BB) design. Mathematical models were generated by regression analysis for responses of PS, EE, and ZP. Two-step experimental design took into account for the preparation of optimized formulation with maximum %EE (72.78 ± 9.7%) and minimum PS (225.67 ± 5.53 nm) at optimum process conditions with a ZP of -5.22 mV for the nano-polymeric formulation in an economical matter by reduction chemical use and formulation time. Furthermore, the biological activity of the final formulation was determined by in vitro cytotoxicity study compared to free MET. The cytotoxicity result reveals that both pure drug and nano-formulation biocompatible with MCF10A non-tumorigenic cell line and lethal for the MCF7 cell line. These in vitro results were the first helpful step to further investigate O-CMC loaded MET nanoparticles in diagnostic and therapeutic applications of breast cancer.

Nanogel loaded with surfactant based nanovesicles for enhanced ocular delivery of acetazolamide

Objective: Intraocular pressure has always been a great challenge for topical ophthalmic drugs. The study aimed to develop ocular surfactant based nanovesicles (NVs) carried in mucoadhesive nanogel providing efficient topical delivery of acetazolamide (ACZ). Methods: For the sake of optimizing formulation parameters, the effect of the type of edge activator and its ratio to sorbitan monostearate (Span 60) on the mean particle size, entrapment efficiency (%EE), and zeta potential (ZP) of produced NVs was investigated. Results: The selected formulation composed of Span 60:sodium deoxycholate with ratio 80:20 showed an average diameter of 202.90 nm, %EE of 90.2%, and ZP of -38.1 mV with a spherical and smooth surface. The ACZ loaded nanovesicles (ACZ-NVs) were embedded in different concentrations of Chitosan-sodium tripolyphosphate (CS-TPP) nanogels. The nanogel prepared using 1.5% CS showed the most promising viscosity, adhesion time, and rheological behavior (118,246 cP, 290 min, and thixotropic behavior, respectively). The in vitro release of ACZ showed a controlled release profile after incorporation in nanogels. The in vivo irritation test showed minimal irritation for the nanogel formulation compared to ACZ topical suspension. The effect of intraocular pressure lowering was significantly prolonged using ACZ-NV nanogels compared to ACZ oral tablets. Histopathological examination emphasized the healing power of CS on retinal atrophy. Conclusion: The research work indicated a promising potential for successful topical delivery of ACZ.

Soy genistein administered in soluble chitosan microcapsules maintains antioxidant activity and limits intestinal inflammation

We used water-soluble Chitosan obtained by Maillard reaction with glucosamine to microencapsulate soy genistein (Ge) and preserve its biological activity for oral administration. Release of Ge was pH dependent with a super Case II mechanism at pH 1.2 and an anomalous transport with non-Fickian kinetics at pH 6.8. Microencapsulated Ge retained its antioxidant properties in vitro and its daily administration to mice attenuated clinical signs of acute colitis, limited inflammatory reaction and reduced oxidative stress and tissue injury as well. Remarkably, after feeding microencapsulated Ge the production of IL-10 in colonic tissue was restored to levels of untreated controls. According to statistical multivariate analysis, this cytokine was the parameter with the highest influence on the inflammatory/oxidative status. Microencapsulation of Ge with derivatized Chitosan becomes an interesting alternative to develop therapeutic approaches for oxidative inflammatory diseases; our findings suggest that the soy isoflavone could be incorporated into any functional food for application in intestinal inflammation.

Optimization of Microwave-Assisted Extraction for the Recovery of Bioactive Compounds from the Chilean Superfruit (Aristotelia chilensis (Mol.) Stuntz)

Maqui berry (Aristotelia chilensis) is being explored in the food industry, and is considered to be one of the healthiest berries due to its bioactive components and high commercial value. Microwave-assisted extraction (MAE) was developed for the determination of total phenolic compounds and anthocyanins from maqui. A Box–Behnken experimental design was employed in conjunction with a response surface methodology to optimize the conditions based on 27 different experiments. The extractions were carried out with four factors (i.e., methanol percentage, pH, temperature, and solvent volume:sample mass ratio), and two responses—total phenolics and anthocyanins. Temperature and methanol percentage were found to be the most influential parameters for total phenolic compounds and anthocyanins, respectively. The optimum MAE conditions were: 65% MeOH in water at pH 2, temperature of 100 °C, and a ratio of 10:0.5 for total phenolics; and 60% MeOH in water at pH 2, temperature of 50 °C, and a ratio of 14:0.5 for anthocyanins. Kinetics assays were carried out and an optimum time of only 2 min was identified for the extractions. Repeatability and intermediate precision were also evaluated, and coefficients of variation below 5% were obtained. The new methods were successfully applied to a foodstuff made with maqui.

Concepts for Developing Physical Gels of Chitosan and of Chitosan Derivatives

Chitosan macro- and micro/nano-gels have gained increasing attention in recent years, especially in the biomedical field, given the well-documented low toxicity, degradability, and non-immunogenicity of this unique biopolymer. In this review we aim at recapitulating the recent gelling concepts for developing chitosan-based physical gels. Specifically, we describe how nowadays it is relatively simple to prepare networks endowed with different sizes and shapes simply by exploiting physical interactions, namely (i) hydrophobic effects and hydrogen bonds-mostly governed by chitosan chemical composition-and (ii) electrostatic interactions, mainly ensured by physical/chemical chitosan features, such as the degree of acetylation and molecular weight, and external parameters, such as pH and ionic strength. Particular emphasis is dedicated to potential applications of this set of materials, especially in tissue engineering and drug delivery sectors. Lastly, we report on chitosan derivatives and their ability to form gels. Additionally, we discuss the recent findings on a lactose-modified chitosan named Chitlac, which has proved to form attractive gels both at the macro- and at the nano-scale.

Enhanced physicochemical stability and efficacy of angiotensin I-converting enzyme (ACE) - inhibitory biopeptides by chitosan nanoparticles optimized using Box-Behnken design

Bromelain-generated biopeptides from stone fish protein exhibit strong inhibitory effect against ACE and can potentially serve as designer food (DF) with blood pressure lowering effect. Contextually, the DF refer to the biopeptides specifically produced to act as ACE-inhibitors other than their primary role in nutrition and can be used in the management of hypertension. However, the biopeptides are unstable under gastrointestinal tract (GIT) digestion and need to be stabilized for effective oral administration. In the present study, the stone fish biopeptides (SBs) were stabilized by their encapsulation in sodium tripolyphosphate (TPP) cross-linked chitosan nanoparticles produced by ionotropic gelation method. The nanoparticles formulation was then optimized via Box-Behnken experimental design to achieve smaller particle size (162.70 nm) and high encapsulation efficiency (75.36%) under the optimum condition of SBs:Chitosan mass ratio (0.35), homogenization speed (8000 rpm) and homogenization time (30 min). The SBs-loaded nanoparticles were characterized for morphology by transmission electron microscopy (TEM), physicochemical stability and efficacy. The nanoparticles were then lyophilized and analyzed using Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). The results obtained indicated a sustained in vitro release and enhanced physicochemical stability of the SBs-loaded nanoparticles with smaller particle size and high encapsulation efficiency following long period of storage. Moreover, the efficacy study revealed improved inhibitory effect of the encapsulated SBs against ACE following simulated GIT digestion.

Fabrication and characterization of complex nanoparticles based on carboxymethyl short chain amylose and chitosan by ionic gelation

The combination of carboxymethyl short chain amylose with chitosan could be considered as a candidate for oral delivery of insulin.