Key Fabrications of Chitosan Nanoparticles for Effective Drug Delivery Using Flow Chemistry Reactors

Introduction

Chitosan nanoparticles have garnered considerable interest in the field of drug delivery owing to their distinctive properties, including biocompatibility, biodegradability, low toxicity, and ability to encapsulate a wide range of drugs. However, the conventional methods (eg, the drop method) for synthesizing chitosan nanoparticles often face limitations in regard to controlling the particle size, morphology, and scalability, hindering their extensive application in drug delivery systems. To overcome these challenges, this study explores using a novel flow chemistry reactor design for fabricating clindamycin-loaded chitosan nanoparticles.

Methods

By varying two critical operating parameters of flow chemistry, namely, the flow rate ratio and total flow rate, the impact of these parameters on the properties of chitosan nanoparticles is investigated using a central composite experimental design.

Results

The optimized conditions for nanoparticle preparation yielded remarkable results, with chitosan nanoparticles exhibiting a small size of 371.60 nm and an extremely low polydispersity index of 0.042. Furthermore, using novel design flow chemistry reactor, the productivity of chitosan nanoparticles was estimated to be 25,402.17 mg/min, which was ~12.71 times higher than that obtained via batch synthesis.

Conclusion

The findings of this study indicate that the use of novel design flow chemistry reactor is promising for synthesizing clindamycin-loaded chitosan nanoparticles and other polymeric nanoparticles intended for drug delivery applications. This is primarily attributed to their ability to produce nanoparticles with a considerably reduced particle size distribution and smaller overall size. The demonstrated high productivity of this technique suggests the potential for industrial-scale nanoparticle manufacturing.

Effects of Sodium Tripolyphosphate Addition on the Dispersion and Hydration of Pure Calcium Aluminate Cement

In this paper, the effect of a sodium tripolyphosphate (STPP) addition on the dispersion and hydration of pure calcium aluminate cement (PCAC) was investigated, and the corresponding mechanism of effect was studied. The effects of STPP on the dispersion, rheology, and hydration processes of PCAC and its adsorption capacity on the surface of cement particles were analysed by measuring the 𝜁-potential on the surface of cement particles, the changes in the concentrations of elemental P and Ca²⁺ ions in a solution at different STPP additions. The experimental results show that STPP easily complexes with Ca²⁺ ions to produce the complex [CaP₃O₁₀]^3- adsorbed on the surface of cement particles, which changes the potential on the surface of cement particles and increases the electrostatic repulsive force between cement particles, thus improving the dispersion and rheology of cement. At the same time, the contact area between cement particles and water is reduced, which hinders the hydration process and makes the time of hydration process longer. A comprehensive analysis shows that the best effect of STPP on pure calcium aluminate cements is achieved when the addition of STPP is 0.2%. This study can provide a reference for the addition of water-reducing agents in refractory castables as well as improving the quality of refractory materials.

Application of Chitosan-Based Molecularly Imprinted Polymer in Development of Electrochemical Sensor for p-Aminophenol Determination

Molecularly Imprinted Polymers (MIPs) have specific recognition capabilities and have been widely used for electrochemical sensors with high selectivity. In this study, an electrochemical sensor was developed for the determination of p-aminophenol (p-AP) by modifying the screen-printed carbon electrode (SPCE) with chitosan-based MIP. The MIP was made from p-AP as a template, chitosan (CH) as a base polymer, and glutaraldehyde and sodium tripolyphosphate as the crosslinkers. MIP characterization was conducted based on membrane surface morphology, FT-IR spectrum, and electrochemical properties of the modified SPCE. The results showed that the MIP was able to selectively accumulate analytes on the electrode surface, in which MIP with glutaraldehyde as a crosslinker was able to increase the signal. Under optimum conditions, the anodic peak current from the sensor increased linearly in the range of 0.5-35 µM p-AP concentration, with sensitivity of (3.6 ± 0.1) µA/µM, detection limit (S/N = 3) of (2.1 ± 0.1) µM, and quantification limit of (7.5 ± 0.1) µM. In addition, the developed sensor exhibited high selectivity with an accuracy of (94.11 ± 0.01)%.

Limiting Pink Discoloration in Cooked Ground Turkey in the Absence or Presence of Sodium Tripolyphosphate Produced from Presalted and Stored Raw Ground Breasts

The effects of pink inhibiting ingredients (PII) to eliminate the pink color defect in cooked turkey breast produced from presalted and stored raw ground turkey in the absence or presence of sodium tripolyphosphate (STP) were examined. Ground turkey breast was mixed with 2% sodium chloride and vacuum packaged. After storage for 6 d, ten PII were individually incorporated without or with added STP (0.5%) as follows: none (control), citric acid (CA; 0.1%, 0.2%, 0.3%), calcium chloride (CC; 0.025%, 0.05%), ethylenediaminetetraacetic acid disodium salt (EDTA; 0.005%, 0.01%), and sodium citrate (SC; 0.5%, 1.0%). Treatments were cooked at a fast or slow cooking rate, cooled, and stored before analysis. All PII tested were capable of lowering inherent pink color compared to the control (No STP: CIE a* pooled day reduction of 23.0%, 5.2%, 12.6%, and 12.6% for CA, CC, EDTA, and SC, respectively; STP: reduction of 21.5%, 17.4%, 6.0%, and 18.2% for CA, CC, EDTA, and SC, respectively). For samples without STP, fast cooking rate resulted in higher CIE a*. However, slow cooking resulted in more red products than fast cooking when samples included STP. Presalting and storage of ground turkey caused the pink discoloration in uncured, cooked turkey (CIE a* 6.24 and 5.12 for without and with STP). This pink discoloration can be decreased by inclusion of CA, CC, EDTA, or SC, but incorporation of CA decreased cooking yield. In particular, the addition of SC may provide some control without negatively impacting the cooking yield.

Zingiber officinale essential oil-loaded chitosan-tripolyphosphate nanoparticles: Fabrication, characterization and in-vitro antioxidant and antibacterial activities

Zingiber officinale essential oil (ZEO) was encapsulated in chitosan nanoparticles at different concentrations using the emulsion-ionic gelation technique and its antioxidant and antibacterial effects were investigated. The results indicated that ZEO level had a significant effect on encapsulation efficiency (EE), loading capacity (LC), particle size and zeta potential. The value obtained for EE, LC, mean particle size and zeta potential were 49.11%-68.32%, 21.16%-27.54%, 198.13-318.26 nm and +21.31-43.57 mV, respectively. According to scanning electron micrographs, the nanoparticles had a spherical shape with some invaginations due to the drying process. The presence of essential oil within the chitosan nanoparticles was confirmed by Fourier transform infrared (FTIR) spectroscopy. In vitro release studies in simulated gastrointestinal fluid (SGF) and simulated intestinal fluid (SIF) indicated an initial burst effect followed by slow release with higher release rate in acidic medium of SGF. ZEO-loaded nanoparticles showed DPPH radical scavenging activity of 20%-61% which increased by raising the ZEO level. Moreover, results of antibacterial activity revealed that Staphylococcus aureus (with inhibition zones of 19-35.19 mm2) and Salmonella typhimurium (with inhibition zones of 9.78-17.48 mm2) were the most sensitive and resistant bacteria to ZEO, respectively. Overall, chitosan nanoparticles can be considered as suitable vehicles for ZEO and improve its stability and solubility.

Development of Gelatin/Misoprostol Compounds for Use in Pregnancy Failures

Early abortion is one of the most common complications during pregnancy. However, the frequent handling of the genital region, more precisely the vagina, which causes discomfort to patients in this abortion process due to the frequency of drug insertion, as four pills are inserted every six hours, has led to the search for alternatives to alleviate the suffering caused by this practice in patients who are already in a shaken emotional state. Hence, this work aimed to develop composites of gelatin and misoprostol, using a conventional single-dose drug delivery system. These composites were prepared by freeze/lyophilization technique, by dissolving the gelatin in distilled water, with a concentration of 2.5% (w/v), and misoprostol was incorporated into the gelatin solution at the therapeutic concentration (800 mcg). They were subsequently molded, frozen and lyophilized. The samples of the composites were then crosslinked with sodium tripolyphosphate (TPP) 1% (v/v) with respect to the gelatin mass for 5 min. The characterization techniques used were: Optical Microscopy (OM), Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetry (TG), Swelling, Biodegradation and Cytotoxicity. In OM it was observed that the addition of the drug improved the cylindrical appearance of the compounds, in comparison with the sample that was composed of only gelatin. There was a reduction in the degree of swelling with the addition of the drug and crosslinking. The cytotoxicity test indicated the biocompatibility of the material. Based on the results obtained in these tests, the composites have therapeutic potential for uterine emptying in pregnancy failures, especially in the first trimester.

Chitosan based controlled release drug delivery of mycophenolate mofetil loaded in nanocarriers system: synthesis and in-vitro evaluation

Background: Organ transplantation is an important and critical procedure, which requires the suppression of immunity, and to suppress the immunity, a constant plasma concentration of immunosuppressant is required.Objectives: The said objective can be achieved by formulating a controlled release drug delivery system of the drug. Chitosan (CHT) nanoparticles (NPs) have been revolutionizing the conventional drug delivery system, for the past two decades. The aim of the current research work was to develop and evaluate CHT-based mycophenolate mofetil (MMF) loaded nanoparticles (CHT/MMF-NPs) using different drug to polymer ratios.Methods: The challenge was to entrap a lipophilic drug within NPs by the ionic gelation method of the positively charged CHT, using tripolyphosphate (TPP) as the crosslinking agent. The prepared CHT/MMF-NPs were evaluated for physical and chemical characterizations, including particle size, surface charge, entrapment efficiency (EE), surface morphology by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) for chemical compatibilities, X-ray diffractometry (XRD) and in-vitro dissolution studies.Results: Outcomes of the studies revealed that particles were 260 ± 17 nm in diameter, with the smooth and regular surface. Satisfactory values of EE (99%) have indicated the suitability of selected ingredients and employed methodology. Moreover, FTIR has confirmed the chemical compatibilities of the formulations. In-vitro dissolution studies have indicated diffusion type of controlled and sustained drug release during 24 h, with zero-order, as best fit kinetic model.Conclusion: Conclusively, the successful achievement of objectives has indicated the suitability of excipients and methodology to prepare CHT/MMF-NPs for better therapeutic outcomes.

Preparation and Characterization of Electrospun Double-layered Nanocomposites Membranes as a Carrier for Centella asiatica (L.)

A wide range of naturally derived and synthetic biodegradable and biocompatible polymers are today regarded as promising materials for improving skin regeneration. Alongside this, these materials have been explored in conjunction with different types of antimicrobial and bioactive agents, especially natural-derived compounds, to enhance their biological properties. Herein, a double-layered nanocomposite dressing membrane was fabricated with two distinct layers. A bottom layer from Chitosan-Sodium tripolyphosphate (CS-TPP) and Poly(vinyl alcohol) (PVA) containing Centella asiatica (L.) (CA) was electrospun directly over a Polycaprolactone (PCL) layer to improve the biologic performance of the electrospun nanofibers. In turn, the PCL layer was designed to provide mechanical support to the damaged tissue. The results revealed that the produced double-layered nanocomposite membrane closely resembles the mechanical, porosity, and wettability features required for skin tissue engineering. On the other hand, the in vitro drug release profile of the PCL/PVA_CS-TPP containing CA exhibited a controlled release for 10 days. Moreover, the PVA_CS-TPP_CA's bottom layer displayed the highest antibacterial activity against Staphylococcus aureus (S. aureus) (99.96 ± 6.04%) and Pseudomonas aeruginosa (P. aeruginosa) (99.94 ± 0.67%), which is responsible for avoiding bacterial penetration while endowing bioactive properties. Finally, the 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay showed that this nanocomposite membrane was not cytotoxic for normal human dermal fibroblasts (NHDF) cells. Therefore, these findings suggest the potential use of the double-layered PCL/PVA_CS-TPP_CA as an efficient bionanocomposite dressing material.

A novel chitosan/tripolyphosphate/L-lysine conjugates for latent fingerprints detection and enhancement

Most chemical and physical methods employed in visualizing latent marks have shown detrimental effects on human health and, therefore, some research groups have directed their attention to the utilization of various (bio)polymers with the aforementioned purpose. Although chitosan is widely used in medicine, pharmacy, food, and drug delivery systems, there are very few studies that address this biopolymer utilization in forensic applications, such as the detection of latent fingerprints. We used chitosan crosslinked with sodium tripolyphosphate and conjugated with L-lysine to enhance the visualization of latent fingerprints, due to its ability to interact with fingerprint sweat residues. These conjugates were prepared using different (w/w) amounts of chitosan and tripolyphosphate (6/1; 4/1; 1/1; 1/4; and 1/6), and those with the most promising results (i.e., 6/1 formulation) were investigated in detail. Fourier transform infrared (FT-IR) spectroscopy confirmed interactions between components of the systems. Optical microscopy and scanning electron microscope (SEM) analysis showed that prepared powder formulations were uniform in size and confirmed that chitosan/tripolyphosphate/lysine conjugates bind easily to the sweat and lipid residues present in the latent fingerprints. The testing of prepared conjugates demonstrated the potential of these systems as bio-based powder substitution for commercially available powders.

The Effects of Addition Timing of NaCl and Sodium Tripolyphosphate and Cooking Rate on Pink Color in Cooked Ground Chicken Breasts

The current study investigated the effects of timing of NaCl (2%) and sodium tripolyphosphate (STPP, 0.5%) addition and cooking rates on color and pigment properties of ground chicken breasts. Four treatments were tested as follows: treatment 1, no NaCl and STPP added and stored for 7 d; treatment 2, NaCl+STPP added on 0 d and stored for 7 d; treatment 3, NaCl added on 0 d and STPP added on 7 d; and treatment 4, stored for 7 d and NaCl+STPP added. All samples were cooked at a fast (5.67°C/min) or slow cooking rate (2.16°C/min). Regardless of the timing of NaCl and STPP addition, reflectance ratios of nitrosyl hemochrome, cooking yield, pH values, oxidation-reduction potential, and percent myoglobin denaturation were similar (p>0.05) across treatments 2, 3, and 4. The highest CIE a* values were observed in treatment 4 (p<0.05), while treatment 2 was effective in reducing the redness in cooked chicken products. The fast cooking rate resulted in lower CIE a* values and higher CIE L* values and cooking yield in cooked chicken breasts compared to the slow cooking rate. Our results indicate that adding NaCl and STPP to meat, followed by storing and cooking at a fast rate, may result in inhibiting the pink color defect sporadically occurred in cooked ground chicken breasts.

Presalting Condition Effects on the Development of Pink Color in Cooked Ground Chicken Breasts

The effects of presalting conditions (storage temperature and duration) with/without sodium tripolyphosphate (STPP) on the color and pigment characteristics of cooked ground chicken breast were investigated. Meat mixtures containing 2% NaCl (control) or 2% NaCl and 0.5% STPP (STPP treatment) were stored for 0, 3, 5, 7, and 10 d at 2°C or 7°C, followed by cooking to 75°C, and cooling and storage at 2°C-3°C until further analysis. The treatment was the most effective on the pink color defect of all independent variables. The effect of storage temperature was only observed on CIE L* values and percentage myoglobin denaturation (PMD). The control was redder than the STPP treated samples and the CIE a* values increased (p<0.05) from 0 to 5 d in the control and STPP treated samples. Compared to the STPP treatment, the control exhibited increased reducing conditions (more negative oxidation reduction potential), lower undenatured myoglobin, and greater PMD. No differences in the cooking yields of the control and STPP-treated samples were observed for various storage durations. Products with STPP showed higher (p<0.05) pH values than those without STPP, but no differences (p>0.05) in PMD were observed over the storage period in the control and STPP treated samples, except for day 0. Thus, STPP is effective at reducing the pink color in cooked chicken breasts. In addition, presalting for longer than 5 d resulted in increased pink color of the cooked chicken breasts.

Staggered Herringbone Microfluid Device for the Manufacturing of Chitosan/TPP Nanoparticles: Systematic Optimization and Preliminary Biological Evaluation

Chitosan nanoparticles (CS NPs) showed promising results in drug, vaccine and gene delivery for the treatment of various diseases. The considerable attention towards CS was owning to its outstanding biological properties, however, the main challenge in the application of CS NPs was faced during their size-controlled synthesis. Herein, ionic gelation reaction between CS and sodium tripolyphosphate (TPP), a widely used and safe CS cross-linker for biomedical application, was exploited by a microfluidic approach based on a staggered herringbone micromixer (SHM) for the synthesis of TPP cross-linked CS NPs (CS/TPP NPs). Screening design of experiments was applied to systematically evaluate the main process and formulative factors affecting CS/TPP NPs physical properties (mean size and size distribution). Effectiveness of the SHM-assisted manufacturing process was confirmed by the preliminary evaluation of the biological performance of the optimized CS/TPP NPs that were internalized in the cytosol of human mesenchymal stem cells through clathrin-mediated mechanism. Curcumin, selected as a challenging model drug, was successfully loaded into CS/TPP NPs (EE% > 70%) and slowly released up to 48 h via the diffusion mechanism. Finally, the comparison with the conventional bulk mixing method corroborated the efficacy of the microfluidics-assisted method due to the precise control of mixing at microscales.

Voltammetric Detection of Lead Using Chitosan-tripolyphosphate Crosslinked Electrode

This paper discusses about the improvement of electrochemical characteristics of graphite paste electrode chemically modified with chitosan through physical crosslinking of the biopolymer with sodium tripolyphosphate. Biopolymer characterizations were performed by scanning electron microscopy, Fourier transform infrared spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical characterization of Pb with graphite paste electrode modified with chitosan crosslinked with sodium tripolyphosphate (GPE-CTS-TPP) showed that the process is quasireversible, controlled by adsorption and involves the transfer of two electrons. Additionally, the physical crosslinking process decreased the electrode resistance as well as improved the electron transfer rate. Once the GPE-CTS-TPP showed enhanced morphological and electrochemical characteristics, it was applied for Pb determination by square wave anodic stripping voltammetry. The method presented appropriate accuracy (recoveries from 95 to 108% and concordance with comparative method between 90 and 107%), high sensitivity (limit of detection and quantification of Pb were 0.73 and 2.44 μg L^-1, respectively) and could be applied to analytical determinations.

Development of Timolol Maleate Loaded Chitosan Nanoparticles For Improved Ocular Delivery

BACKGROUND

The poor retention and penetration are the major issues in the bioavailability of drugs through ocular route. Recently, the natural polymers have been exploited for the development of nanoparticles to improve the ocular performance of various drugs. In the present investigation, nanoparticles of timolol maleate (TM) were developed by using chitosan polymer to improve its release through ocular delivery.

METHOD

Ionic gelation method was used for the development of timolol loaded chitosan nanoparticles by using a cross linking agent, sodium tripolyphosphate (NaTPP). The Box- Behnken design was used for the optimization of various parameters for the development of nanoparticles.

OBJECTIVE

The objective behind the study was to study the effect of three critical parameters; concentration of chitosan (X1), the concentration of NaTPP (X2), and the volume of NaTPP (X3) on the drug release from the prepared nanoparticles.

RESULTS

The results obtained showed that high level of the chitosan concentration and low level of the NaTPP concentration and the mid levels of the NaTPP volume resulted in high levels of encapsulation efficiency. The loading capacity was found maximum at a low level of chitosan and mid level of volume of the NaTPP with a low level of NaTPP concentration. The optimized batch (NP-2) showed that the entrapment efficiency was 75.34±0.17%, the particle size of 190.9 nm and in vitro cumulative percentage of drug release was 49.11±0.49% in 12 h.

CONCLUSION

The study concluded that chitosan nanoparticles loaded with timolol maleate resulted in improved drug release for ocular treatment.

The influence of additives on frozen snakehead fish surimi and the application of transglutaminase to fish cakes

BACKGROUND

The co-product of cultured snakehead fish protein extraction is an abundant source of myofi- brillar protein, with the potential for application in the processing of frozen snakehead fish surimi. The objective of this study was to determine the influence of additives and incubation time on the quality of surimi and surimi-based products.

METHODS

Cryoprotectant (a mixture of sucrose and sorbitol at a ratio of 1:1 changed from 2% to 4%), in combination with sodium tripolyphosphate (0.1, 0.15, 0.2 and 0.25%), was added to surimi during its preparation. In addition, the study also investigated the ratio of transglutaminase supplementation (0.5, 0.7 and 0.9%) and incubation time (2, 4 and 6 h) in the processing of high-quality fried fish cakes from frozen snakehead fish surimi.

RESULTS

The results showed that, a combination of 3% cryoprotectant and 0.2% sodium tripolyphosphate helped maintain the quality of snakehead fish surimi after frozen storage. In the processing of fried fish cakes from frozen snakehead fish surimi, the addition of 0.7% transglutaminase (0.28 U/g surimi) with 4 h incubation significantly improved the gel properties of the product.

CONCLUSIONS

It is necessary to have appropriate additives and incubation time in the processing of surimi and surimi-based products from the co-product of cultured snakehead fish protein extraction.

Formation of macromolecules in wheat gluten/starch mixtures during twin-screw extrusion: effect of different additives

BACKGROUND

Wheat gluten comprises a good quality and inexpensive vegetable protein with an ideal amino acid composition. To expand the potential application of wheat gluten in the food industry, the effect of different additives on the physicochemical and structural properties of wheat gluten/starch mixtures during twin-screw extrusion was investigated.

RESULTS

Macromolecules were observed to form in wheat gluten/starch mixtures during twin-screw extrusion, which may be attributed to the formation of new disulfide bonds and non-covalent interactions, as well as Maillard reaction products. Additionally, the water retention capacity and in vitro protein digestibility of all extruded wheat gluten/starch products significantly increased, whereas the nitrogen solubility index and free sulfhydryl group (SH) content decreased, during twin-screw extrusion. Secondary structural analysis showed that α-helices disappeared with the concomitant increase of antiparallel β-sheets, demonstrating the occurrence of protein aggregation. Microstructures suggested that the irregular wheat gluten granular structure was disrupted, with additive addition favoring transformation into a more layered or fibrous structure during twin-screw extrusion.

CONCLUSION

The findings of the present study demonstrate that extrusion might affect the texture and quality of extruded wheat gluten-based foods and suggest that this process might serve as a basis for the high-value application of wheat gluten products. © 2017 Society of Chemical Industry.

Physiochemical, texture properties, and the microstructure of set yogurt using whey protein-sodium tripolyphosphate aggregates as thickening agents

BACKGROUND

Polymerized whey protein-sodium tripolyphosphate can be induced to gel in an acidic environment provided during fermentation. The variety of thickening agent has an influence on texture that is an essential aspect of yogurt quality affecting consumer preference. Similar to polysaccharide stabilizers, the cold gelation properties of whey proteins can improve the body texture of yogurt products. Polymerized whey protein-sodium tripolyphosphate could be a favorable and interesting thickening agent for making set yogurt.

RESULTS

The effects of whey protein isolate (WPI), heat-treated whey protein-sodium tripolyphosphate (WPI-STPP), heat-treated WPI and pectin on the storage properties and microstructure of yogurt were investigated. All samples were analyzed for syneresis, pH, titratable acidity, viscosity, texture profile and microstructure during storage. The results showed that incorporating heat-treated WPI-STPP had a significant impact on syneresis (32.22 ± 0.60), viscosity (10 956.67 ± 962.1) and hardness (209.24 ± 12.48) (p < 0.05) with uniform body texture.

CONCLUSION

Yogurt fermented with modified WPI-STPP had higher levels of protein and better hardness compared with yogurt using pectin. The microstructure was observed to be a uniform and denser, complicated network. Heat-treated WPI-STPP may be useful for improving yogurt texture. © 2016 Society of Chemical Industry.

Effects of ultrasound, CaCl2 and STPP on the ultrastructure of the milk goat longissimus muscle fiber observed with atomic force microscopy

The aim of this study was to analyze the effects of ultrasound bath intensity, CaCl₂ and sodium tripolyphosphate (STPP) concentration on the ultrastructure of longissimus muscle fiber from milk goats. The sarcomere length was measured by atomic force microscopy. According to the results of AFM images, the sarcomere length is longest when the conditions were an intensity of 100 W ultrasound bath (42.77% increment), a concentration of 300 mM CaCl₂ injection (44.68% increment) or 90 mM STPP injection (19.41% increment). Apart from the sarcomere length, the study put forward a potential index (roughness) to represent tenderness of meat which was treated by ultrasound bath. Among different methods, ultrasound bath was chosen as the preferred tenderization method. SCANNING 38:545-553, 2016. © 2016 Wiley Periodicals, Inc.

Structural and compositional changes in the salivary pellicle induced upon exposure to SDS and STP

Sodium dodecyl sulphate (SDS) and sodium tripolyphosphate (STP) act to remove stained pellicle from dentition and loosen deposits on tooth surfaces that may become cariogenic over time. This study investigated how SDS and STP impact the salivary pellicle adsorbed onto hydroxyapatite and silica sensors using a dual polarisation interferometer and a quartz-crystal microbalance with dissipation. After the pellicle was exposed to SDS and STP the remaining pellicle, although weaker, due to the loss of material, became less dense but with a higher elastic component; suggesting that the viscous component of the pellicle was being removed. This would imply a structural transformation from a soft but dense structured pellicle, to a more diffuse pellicle. In addition, the majority of proteins displaced by both SDS and STP were identified as being acidic in nature; implying that the negatively charged groups of SDS and STP may be responsible for the displacement of the pellicle proteins observed.

Alginate coated chitosan core shell nanoparticles for oral delivery of enoxaparin: in vitro and in vivo assessment

The objective of present research work was to develop alginate coated chitosan core shell nanoparticles (Alg-CS-NPs) for oral delivery of low molecular weight heparin, enoxaparin. Chitosan nanoparticles (CS-NPs) were synthesized by ionic gelation of chitosan using sodium tripolyphosphate. Core shell nanoparticles were prepared by coating CS-NPs with alginate solution under mild agitation. The Alg-CS-NPs were characterized for surface morphology, surface coating, particle size, polydispersity index, zeta potential, drug loading and entrapment efficiency using SEM, Zeta-sizer, FTIR and DSC techniques. Alginate coating increased the size of optimized chitosan nanoparticles from around 213 nm to about 335 nm as measured by dynamic light scattering in zeta sizer and further confirmed by SEM analysis. The performance of optimized enoxaparin loaded Alg-CS-NPs was evaluated by in vitro drug release studies, in vitro permeation study across intestinal epithelium, in vivo venous thrombosis model, particulate uptake by intestinal epithelium using fluorescence microscopy and pharmacokinetic studies in rats. Coating of alginate over the CS-NPs improved the release profile of enoxaparin from the nanoparticles for successful oral delivery. In vitro permeation studies elucidated that more than 75% enoxaparin permeated across the intestinal epithelium with Alg-CS-NPs. The Alg-CS-NPs significantly increased (p<0.05) the oral bioavailability of enoxaparin in comparison to plain enoxaparin solution as revealed by threefold increase in AUC of plasma drug concentration time curve and around 60% reduction in thrombus formation in rat venous thrombosis model. The core shell Alg-CS-NPs showed promising potential for oral delivery and significantly enhanced the in vivo oral absorption of enoxaparin.

Fabrication and in vitro evaluation of mucoadhesive ondansetron hydrochloride beads for the management of emesis in chemotherapy

Background

Mucoadhesive beads were fabricated and evaluated for controlled release of an antiemetic drug ‘Ondansetron Hydrochloride’. Ondansetron hydrochloride is a serotonin 5-HT₃ receptor antagonist mainly used for the treatment of emesis, which occurs as a side effect of chemotherapy.

Materials and Methods:

The present work was to fabricate and evaluate ondansetron-loaded microbeads by using chitosan as mucoadhesive and sustained release polymer. Sodium tripolyphosphate (Na-TPP) was used as a cross-linking agent. The microbeads were successfully prepared by ionotropic gelation technique. The particle size, entrapment efficiency, and mucoadhesive strength of drug-loaded formulations was measured by an optical microscope, direct crushing method, and in vitro wash-off method, respectively.

Results:

Particle size, entrapment efficiency, mucoadhesive strength, and in vitro drug release of optimized formulation was found to be 760.11 ± 1.02 μm, 75.09 ± 2.40%, 95.14 ± 0.27% and 87.45 ± 1.21%, respectively. The data was fitted to different kinetic models to illustrate its anomalous (non-Fickian) diffusion.

Conclusions:

The results revealed that ondansetron HCl loaded microbeads are most suitable mode of drug delivery for promising therapeutic action. Ondansetron HCl-loaded microbeads can prove to be potential pharmaceutical dosage forms for sustaining the drug release and reducing the dose frequency.

Synchronous fluorescence determination of ferulic acid with Ce(IV) and sodium tripolyphosphate

In this study, a synchronous fluorescence detection method for ferulic acid (FA) is proposed based on a redox reaction between FA and Ce(IV) sulfate in dilute sulfuric acid medium at room temperature. It was found that FA could reduce Ce(IV) to Ce(III) in acidic medium, and sodium tripolyphosphate could further enhance the intrinsic fluorescence of the Ce(III) produced. The enhanced extent of synchronous fluorescence intensity was in proportion to the concentration of FA over the range 3.0 × 10(-8) to 1.0 × 10(-5) mol/L. The corresponding limit of determination (S/N = 3) was 1.3 × 10(-8) mol/L. The proposed method was applied to the determination of sodium ferulate for injection sample with satisfactory results.