Release Kinetic Models Research Articles

Gated Organonanoclays for Large Biomolecules: Controlled Release Triggered by Surfactant Stimulus

The low toxicity and high adsorption capacities of clay minerals make them attractive for controlled delivery applications. However, the number of controlled-release studies in the literature using clay minerals is still scarce. In this work, three different clays from the smectite group (Kunipia F, montmorillonite; Sumecton SA, saponite; and Sumecton SWN, hectorite) were successfully loaded with rhodamine B dye and functionalized with oleic acid as a gatekeeper to produce organonanoclays for active and controlled payload-release. Moreover, hematin and cyanocobalamin have also been encapsulated in hectorite gated clay. These organonanoclays were able to confine the entrapped cargos in an aqueous environment, and effectively release them in the presence of surfactants (as bile salts). A controlled delivery of 49 ± 6 μg hematin/mg solid and 32.7 ± 1.5 μg cyanocobalamin/mg solid was reached. The cargo release profiles of all of the organonanoclays were adjusted to three different release-kinetic models, demonstrating the Korsmeyer–Peppas model with release dependence on (i) the organic–inorganic hybrid system, and (ii) the nature of loaded molecules and their interaction with the support. Furthermore, in vitro cell viability assays were carried out with Caco-2 cells, demonstrating that the organonanoclays are well tolerated by cells at particle concentrations of ca. 50 μg/mL.

Formulation and Characterization of Tenofovir Disproxyl Fumerate Nanoparticles prepared by Nanoprecipitation Method

Tenofovir disproxyl fumerate (TDF) is widely used drug in anti HIV treatment. The main disadvantage with TDF is its low bioavailability. To overcome this problem TDF is formulated in to nanoparticles by using nanoprecipitation method. The formulated nanoparticles were in the range of 106.8nm to 516.4nm. The effect of PLGA and TPGS on the formulated nanoparticles were also studied. It is evident that the concentration of PLGA played an important role in the entrapment and drug loading capacity. On the basis of drug loaded and entrapment efficiency the F8 formulation was considered as optimized formulation. Different analytical techniques were used to determine the amount of drug present in the optimized formulation. The optimized formulation (F8) was subjected to different drug release kinetic models and its stability studies were also conducted in accordance with ICH guidelines.

Characterization and release kinetics model of thymol from starch-based nanocomposite film into food simulator.

To improve the performance of potato starch films and solve the problems of high volatility and low stability of thymol (Thy), thymol was loaded into the channel of SBA-15 to prepare Thy-SBA-15, and the Thy-SBA-15/potato starch film was prepared. The results showed thymol was successfully loaded into the pores of SBA-15. The addition of Thy-SBA-15 enhanced the tensile strength of potato starch film (3.93 Mpa), reduced the water vapor permeability (1.56 × 10-12 g·d-1 m-1 Pa-1 , WVP) and moisture absorption (80.97%, MA), which enhanced the barrier properties of the films. Thy-SBA-15 had good compatibility with potato starch films. Notably, the thymol released from Thy-SBA-15/potato starch film was initially explosive, and then continuous, which showed this film could effectively slow down the release rate of thymol and prolong the fresh-keeping period of food. The Korsmeyer-Peppas model (R2 > .96) had the best fit for the release curve of thymol. PRACTICAL APPLICATIONS: This work offers a new method for the preparation of potato starch sustained-release antibacterial film, and provides a theoretical basis and technical support for the development of intelligent packaging.

Formulation and Evaluation of Moxifloxacin Loaded Bilosomes In-Situ Gel: Optimization to Antibacterial Evaluation.

In this study, moxifloxacin (MX)-loaded bilosome (BS) in situ gel was prepared to improve ocular residence time. MX-BSs were prepared using the thin-film hydration method. They were optimized using a Box–Behnken design (BBD) with bile salt (A, sodium deoxycholate), an edge activator (B, Cremophor EL), and a surfactant (C, Span 60) as process variables. Their effects were assessed based on hydrodynamic diameter (Y1), entrapment efficacy (Y2), and polydispersity index (Y3). The optimized formulation (MX-BSop) depicted a low hydrodynamic diameter (192 ± 4 nm) and high entrapment efficiency (76 ± 1%). Further, MX-BSop was successfully transformed into an in situ gel using chitosan and sodium alginate as carriers. The optimized MX-BSop in situ gel (MX-BSop-Ig4) was further evaluated for gelling capacity, clarity, pH, viscosity, in vitro release, bio-adhesiveness, ex vivo permeation, toxicity, and antimicrobial properties. MX-BSop-Ig4 exhibited an optimum viscosity of 65.4 ± 5.3 cps in sol and 287.5 ± 10.5 cps in gel states. The sustained release profile (82 ± 4% in 24 h) was achieved with a Korsmeyer–Peppas kinetic release model (R2 = 0.9466). Significant bio-adhesion (967.9 dyne/cm2) was achieved in tear film. It also exhibited 1.2-fold and 2.8-fold higher permeation than MX-Ig and a pure MX solution, respectively. It did not show any toxicity to the tested tissue, confirmed by corneal hydration (77.3%), cornea histopathology (no internal changes), and a HET-CAM test (zero score). MX-BSop-Ig4 exhibited a significantly (p < 0.05) higher antimicrobial effect than pure MX against Staphylococcus aureus and Escherichia coli. The findings suggest that bilosome in situ gel is a good alternative to increase corneal residence time, as well as to improve therapeutic activity.

Anti-microbial Nanohybrids Based on Naturally Derived Citric Acid Intercalated Layered Double Hydroxides

Currently, there is an increased demand for advanced food packages, which can significantly increase the shelf life of food items. In the current context, it is envisaged that nanotechnology has the potential to address stability, toxicity, shelf-life, and low-cost issues of antimicrobials associated with the packaging industry. Antimicrobial nanocomposite systems are believed to be more efficient than their microscale counterparts due to the high surface area to volume ratio and quantum mechanical involvement in deciding their properties. As a result of high surface area, they are able to attach more copies of microbial molecules and cells, thus reducing the quantity of material required while significantly improving their activity. This study focuses on the development of slow-release antimicrobial material based on natural citrate (α-hydroxycitrate) intercalated layered double hydroxide (LDH) nanohybrid. Natural citrate ions available in Citrus aurantifolia (lime) were extracted by a simple chemical method and intercalated into Mg-Al-Layered Double Hydroxide following a one-step co-precipitation method. Successful intercalation of the citrate ion was confirmed by powder X-ray diffraction (PXRD) and Fourier transform infrared (FTIR) spectroscopic analysis. Release kinetics of resulted nanohybrid was studied and compared using different release kinetic models. Antimicrobial properties of this novel nanohybrid were confirmed against two common food pathogens, Colletotrichum gloeosporioides and Saccharomyces cerevisiae, and the results were compared against sodium benzoate, which is the commonly used commercial antimicrobial agent in the food industry. Successful intercalation of natural citrate ions into LDH and its activity against the tested microbes show the potential of using it as a slow-release nanohybrid material in many food-related applications.&#x0D; &#x0D; Keywords: Layered Double Hydroxide, α-Hydroxycitrate, Natural, Safe, Lime Extract, Slow Release, Antimicrobial

Formulation, characterization and ex vivo study of curcumin nano-invasomal gel for enhanced transdermal delivery

Curcumin is a complex molecule with substantial activity against a number of diseases but its limited water solubility and low skin penetration offer significant challenges to its transdermal distribution and performance thus for enhancing its transdermal application curcumin-loaded invasomes were prepared using mechanical dispersion process. Invasomes were characterised and optimised in terms of entrapment efficiency, vesicle size, in vitro drug release, ex vivo permeation and skin retention studies. A topical gel was prepared from the optimized invasomal formulation. In vitro release study of invasomal gel affirmed well with Higuchi kinetic model for release. Ex vivo study confirmed that the curcumin permeation across the pig ear skin from the invasomal gel was 2.60 times higher and had a flux of 166.02 ± 0.13 µg/cm2/h. The study's findings suggest that invasomes have a high potential for transdermal administration of curcumin which can increase the topical utility of curcumin in several skin diseases.

Application of Cyperus esculentus oil in the development of sustained release diclofenac sodium-loaded nanostructured lipid carrier

The aim of the work was to develop sustained release diclofenac sodium nanostructured lipid carrier (NLC) using tigernut oil (TNO), solid lipids and polyethylene glycol 4000 (PEG 4000) and to evaluate the properties of the formulations. Structured lipids containing tiger nut oil, Softisan®154 and Phospholipon® 90H at varying ratios were prepared by fusion and used as the lipid carrier in formulating the NLC. PEGylated lipid carriers were also employed and the physicochemical properties of these formulations were studied using standard methods including particle size and polydispersity index, encapsulation efficiency, loading capacity and drug release. The results revealed some monodispersed nano-sized formulations that were stable over time. Particle size ranged from 75.22 ± 22.72 nm to 78.11 ± 32.73 nm. High encapsulation efficiency of about 92 % was obtained confirming the suitability of the TNO based carrier. In vitro drug release in simulated intestinal fluid (pH 7.2) revealed that PEGylated diclofenac sodium-loaded NLC exhibited significantly higher sustained release properties than the non-PEGylated formulations (p &lt;0.05). The results of the drug release kinetics models revealed that the NLC followed a mixed order release kinetic. Hence, the findings in this work showed that TNO could be used as a lipid carrier matrix in combination with other solid lipids for the development of sustained release diclofenac sodium-loaded nanostructured lipid carrier.

PRODUCTION OF GANODERMA LUCIDUM EXTRACT LOADED GELATIN-SODIUM ALGINATE MICROSPHERES, INVESTIGATION OF RELEASE KINETICS AT DIFFERENT pH VALUES AND EVALUATION OF KINETIC MODELS

In this study, pH sensitive microsphere polymeric drug carriers were produced by using biodegradable natural gelatin and sodium alginate polymers. Microspheres were loaded with prepared Ganoderma lucidum extract that is a medicinal mushroom and has the potential to be used in several diseases’ treatment. Extract release kinetics of the microspheres were examined by spectrophotometric method by using an UV spectrometer. Buffer solutions with different pH values were used as release medium for examination of drug release kinetics of the produced microspheres. The Ganoderma lucidum release of microspheres was presented in terms of percent cumulative release (CR%) defined as the percentage ratio of the instantaneous amount of Ganoderma lucidum released at a certain time of incubation to the initial amount of Ganoderma lucidum loadings. As a result, it was seen that the release of the extract accelerated as pH of the release medium increased and the fastest extract release was observed in the pH 7. The release kinetic models of the microspheres were examined. The release kinetics of microspheres fitted Higuchi model for pH 1.3, pH 5.0 and pH 6.0 and first-order model for pH 3.0 and pH 7.0.

Synthesis and characterization of double network hydrogel based on gellan-gum for drug delivery

The fabrication of a suitable polymeric network could help to design an efficient drug delivery platform for modulating the release of therapeutic molecules. To this aim, the fabrication of a new gellan-based magnetic double network hydrogel nanocomposite (MDNH) was investigated in the current work. The crosslinking agents were prepared by samples of Gellan/PAMPS/PAAm DN hydrogels with different amounts of Fe2+/Fe3+ and N, N’-methylenebis acrylamide (MBA) components for investigating their drug delivery and mechanical features. The structure of synthesized MDNH was determined by employing the characterization techniques such as FTIR, TEM, VSM, DSC, FESEM, and TGA. The mechanical strengths of models were also measured (σf of 325.2 KPa, εf of 0.69 mm/mm). The synthesized MDNH showed an appropriate modulating control for releasing kinetics of the investigated Metformin Hydrochloride (MH) drug besides showing a good mechanical feature. In vitro release of MH from the drug-loaded hydrogel was examined in pH 5.4 (PBS) and pH 7.4 (PBS) media. Based on the obtained results, decreasing the medium pH from 7.4 to 5.4 accelerate the MH release from 50% at pH = 7.4 up to 84% at pH = 5.4 after a period of 1500 min. The applicability of drug release kinetic models was proved.

Amphotericin B release rate is the link between drug status in the liposomal bilayer and toxicity

Amphotericin B (AmB) is an amphiphilic drug commonly formulated in liposomes and administered intravenously to treat systemic fungal infections. Recent studies on the liposomal drug product have shed light on the AmB aggregation status in the bilayer, which heat treatment (curing) modifies. Although toxicity was found related to aggregation status - loose aggregates significantly more toxic than tight aggregates - the precise mechanism linking aggregation and toxicity was not well understood. This study directly measured drug release rate from various AmB liposomal preparations made with modified curing protocols to evaluate correlations among drug aggregation state, drug release, and in vitro toxicity. UV–Vis spectroscopy of these products detected unique curing-induced changes in the UV spectral features: a ∼25 nm blue-shift of the main absorption peak (λmax) in aqueous buffer and a decrease in the OD346/OD322 ratio upon thermal curing, reflecting tighter aggregation. In vitro release testing (IVRT) data showed, by applying and fitting first-order release kinetic models for one or two pools, that curing impacts two significant changes: a 3–5-fold drop in the overall drug release rate and a ten-fold decrease in the ratio between the loosely aggregated and the tightly aggregated, more thermodynamically stable drug pool. The kinetic data thus corroborated the trend independently deduced from the UV–Vis spectral data. The in vitro toxicity assay indicated a decreased toxicity with curing, as shown by the significantly increased concentration, causing half-maximal potassium release (TC50). The data suggest that the release of AmB requires dissociation of the tight complexes within the bilayer and that the reduced toxicity relates to this slower rate of dissociation. This study demonstrates the relationship between AmB aggregation status within the lipid bilayer and drug release (directly measured rate constants), providing a mechanistic link between aggregation status and in vitro toxicity in the liposomal formulations.

Survey of antibacterial activity and release kinetics of gold-decorated magnetic nanoparticles of Fe0 conjugated with sulfamethoxazole against Escherichia coli and Staphylococcus aureus

Drug delivery of antibiotics with magnetic nanoparticles improved by coating metals such as gold and silver has recently been studied. This work describe a simple method to synthesize modified magnetic nanoparticles which have high ability to modify the customary formulation of antibiotics such as sulfamethoxazole (SMX) and pursuant study of adsorption-desorption (release) of this drug. These synthesized nanoparticles were characterized by different methods, including field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and mapping, Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating-sample magnetometry, thermogravimetric analysis and zeta potential test. Present assay showed a well correlation with the introduced carrier for the drug. Also the hypothesis were proved by some adsorption isotherm models and drug kinetics studies of carriers with different drug release kinetics models. This study confirmed the adsorption isotherm models and kinetics of drug sorbate are Temkin and Pseudo-First-Order Lagergren models, respectively; the kinetics of drug release from this carrier is based on Zero-Order model. The values of MIC in antibacterial test for pure SMX and SMX conjugated nanoparticles against Escherichia coli were calculated to be 14 and 2.5 μg/mL, respectively, and these values against Staphylococcus aureus were 24 and 1.25 μg/mL, respectively.

Optimization of the Preformulation and Formulation Parameters in the Development of New Extended-Release Tablets Containing Felodipine

Herein, new extended-release tablets containing felodipine were developed. For the orally administered formulations, optimization of the preformulation and formulation parameters was performed to assess the performance of the dosage form. Initially, the morphological and physical characterization of two forms of felodipine (microcrystalline and macrocrystalline) using Fourier transform infrared spectroscopy, differential scanning calorimetry and optical microscopy was performed. The pharmaco-technical properties of the two felodipine forms were also determined. Subsequently, formulation studies for felodipine extended-release tablets were performed. Mathematical modelling of release kinetics of felodipine from developed formulations using a power law model was also performed. Based on the influence of formulation factors on the in vitro availability of felodipine in experimental tablets, a new extended-release tablet formulation was established.

PEDOT: PSS‐Based Microfluidic‐Spun Microfibers for Tunable Release of Acetaminophen via Electrical Stimulation

AbstractTransdermal drug delivery system (TDDS) is effective in alleviating patient's pain and reduces frequent administration. Realizing tunable drug release on fibers/fabrics is important for constructing TDDS platform with good skin affinity and long‐term comfortability. Herein, a conductive fiber consisting of polyvinyl pyrrolidone/sodium alginate/ acetaminophen/poly(3,4‐ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) (PVP/SA/AAP/PEDOT: PSS, PSAP) is fabricated by core‐shell microfluidic spinning technology for the controllable release of AAP, a typical pain reliever. Incorporation of conductive fillers endows fibers with microcracks that are responsive to electrical stimulation for promoting drug diffusion and release. The release rate of AAP in simulated body fluid can be improved from 70.81% to 92.07% under electric stimulation, demonstrating a regulable release process enabled by tunable fiber conductivity and applied voltage (0–1.5 V). The drug release kinetic model reveals Fickian diffusion dominates the release process of AAP that generates local concentration difference in the microcracked PSAP fiber with electrical stimulation. This work proposes an accurate fabrication strategy of fibers‐based TDDS that is promising for wearable biomedical electronics and self‐powered on‐demand drug delivery systems.

Effect of Surface Functionalization and Pore Structure Type on the Release Performance of Mesoporous Silica Nanoparticles

Based on the excellent physicochemical properties of mesoporous silica nanoparticles (MSN), the application of MSN in drug delivery has become a popular strategy. However, a wide variety of MSN structures and surface modification affect the drug loading and release, thus affecting the effectiveness of drug delivery system. Therefore, the effects of MSN type, pore structure and modified functional groups on drug release properties were investigated in this paper. A series of MSN was synthesized by sol-gel method, and the mesopore type and pore size were adjusted. Their surfaces were modified by amino groups (NH 2 ) and polydopamine (PDA) to change the surface charge. Anticancer Doxorubicin (DOX) was used as a model drug to study effects of different types of MSN on drug loading and release. MSN with hollow structure had a large inner cavity for DOX loading and tiny pore shell to prevent DOX loss, leading to higher loading capacity. MSN with surface-modified amine was positively charged and processed good pH responsiveness and accelerated DOX release. Thus hexagonal pore MSN-NH 2 and MSN-PDA were the anticancer DOX delivery carriers with better combined release performance in terms of pH-responsive performance and sustained release effect. Finally, several kinetic models were measured to fit the in vitro DOX release data and the results showed that release behaviors of different MSNs were more consistent with Korsmeyer-Peppas release kinetic model. All of them were Fick diffusion-controlled except for the second release stage of hollow MSN at pH 7.4, which was non-Fick diffusion release. • A series of MSNs with diverse structures and modification were studied. • Specific surface area, pore volume/type and surface charge affected drug loading. • Diverse kinetic models were employed to investigate mechanism of drug release. • MSNs with modification were drug delivery systems with better release performance.

To Study the effect of Cross linking of Sodium Alginate on the Rate of Drug Release

Verapamil hydrochloride (VH) is a calcium channel blocking agent used in the treatment of hypertension, cardiac arrhythmia and angina pectoris. The short half life and high frequency of administration of VH makes it a suitable candidate for designing sustained drug delivery system. The aim of the present investigation was to develop a sustained release matrix tablet of verapamil hydrochloride (VH) using sodium alginate and cross linked sodium alginate and to evaluate the drug release kinetics. In order to achieve the required sustained release profile, the tablets were prepared by a wet granulation method. The formulated tablets were characterized for pre-compression and post-compression parameters and they were in the acceptable limits. The drug release data obtained after an in vitro dissolution study was fitted to various release kinetic models in order to evaluate the release mechanism and kinetics. The criterion for selecting the best fit model was linearity (coefficient of correlation). Drug release mechanism was found to follow a complex mixture of diffusion, swelling and erosion. The dosage form holds the potential to control the release rate of drug and extend the duration of action of a drug.

Assessing potassium release in natural silica sand from novel K-enriched sewage sludge biochar fertilizers

Enrichment of biochars to produce slow nutrient release fertilizers with minimal losses to the environment is a promising strategy. However, the release of potassium (K) from biochar-based fertilizer produced from sewage sludge (SS) is still poorly studied. In the present 30-day incubation study, the dynamics of K release were evaluated from SS biochar-based fertilizers enriched with potassium chloride (KBF) in different forms, subjected to two levels of silica sand moisture (10 and 20%). The KBF was evaluated in the form of granules, pellets and powder, in addition to pure KCl mineral fertilizer. During the incubation period water-soluble K extractions were performed, where the K contents were adjusted to K release kinetic models. An additional experiment was performed to assess the effect of KBFs and KCl on K leaching. In general, at both moisture levels all KBFs presented a slower K release compared to pure KCl mineral fertilizer, reducing the release rate by up to 77%. The K release dynamics were affected by the type of biochar fertilizer (granule, pellet and powder) and the silica sand moisture level. The behavior of KBFs as slow-release fertilizers is strongly dependent on the silica sand moisture level. At the 10% moisture level, biochar fertilizers in the form of pellets and granules can be classified as slow-release fertilizers with the potential to increase the efficiency of K use in agriculture. Furthermore, compared to the chemical fertilizer, KBF reduced the amount of leached K, diminishing the risk of this nutrient polluting the groundwater. Our results must be further assessed in real conditions using soil as a suitable medium for agronomic and environmental evaluation. Therefore, future studies should consider the dynamic of K and other nutrients from KBFs in distinct soil types.

A Comparative Evaluation of Sustained Release of Chlorphenamine Based on a Nanocomposite of Chitosan, Pectin and Montmorillonite

AbstractThe scenario of the current investigation is to prepare an inclusion complex (IC) of chlorphenamine (CPM) and montmorillonite (MONT) by microwave method for sustained drug delivery system and to analyze the comparison of inclusion complex with direct loading of free drug. A nanocomposite was synthesized from chitosan (CH), pectin (PC) by incorporating montmorillonite (MONT). The confirmation of inclusion complex formation and nanocomposite was characterized by FTIR, XRD, and FESEM‐EDS. Drug release study from chitosan, pectin nanocomposite containing free CPM and inclusion complex of CPM: MONT were investigated under different pH 2, 7 and 7.4 at 37 °C. The concentration of drug release from inclusion complex loaded nanocomposite was found to be 97.4 % in 22 hours. Four different kinetic models were studied to check the real mechanism involved in drug release. In all cases, the best fitted kinetic model for CPM release from the inclusion complex loaded nanocomposite was Peppas‐Sahlin and Korsmeyer Peppas, implying that diffusion and relaxation phenomena were responsible for the drug release. Diffusion phenomena have more contribution than relaxation is confirmed by the Peppas‐Sahlin equation. Montmorillonite is responsible for the sustained drug release because of host‐guest interactions. Montmorillonite has a layered structure that allows it to intercalate the drug molecule into its cavity, resulting in sustained chlorphenamine release.

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.

Curcumin Loaded onto Magnetic Mesoporous Material MCM-41 for Controlled and Released in Drug Delivery System

In this work, the mesoporous silica nanoparticles (MSNs) of type MCM-41 were manufactured and modified with Fe3O4 to load curcumin (CUR) CUR@Fe3O4/MCM-41 as an efficient carrier in drug delivery systems. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FT-IR), and nitrogen adsorption-desorption isotherms were used to characterize the three samples: pure MCM-41, Fe3O4/MCM-41, & CUR@Fe3O4/MCM-41. Adsorption processes tests were carried out to determine the impact of various variables on the CUR load efficiency. These variables were the carrier dosage, pH, contact time, and initial CUR concentration. The maximal drug loading efficiencies (DL %) were 15.78 % and 22.98 %, respectively. According to the data, The Freundlich isotherm had a stronger correlation coefficient R2= 0.999 for MCM-41, while the Langmuir isotherm had a greater R2 of 0.9666 for Fe3O4/MCM-41. A pseudo-second-order kinetic model fits well with R2=0.9827 for MCM-41 and 0.9994 for Fe3O4/MCM-41. Phosphate Buffer Solution (PBS) with a pH of 7.4 was utilized to study CUR release behavior. According to the research, the maximum release for MCM-41 and Fe3O4/MCM-41 might be 74.1 % and 25.19 % after 72 h, respectively. Various kinetic release models were used, including First-order, Korsmeyer-Peppas, Hixson and Crowell, Higuchi, and Weibull. After 72h, the drug release data were fit using a Weibull kinetic model with an R2 of 0.944 and 0.764 for MCM-41 and Fe3O4/MCM-41, respectively.

Carboxymethyl cellulose-based nanocomposite hydrogel grafted with vinylic comonomers: synthesis, swelling behavior and drug delivery investigation

Carboxymethyl cellulose-based nanocomposite hydrogel was produced through in-situ free-radical copolymerization for use in drug delivery study. The pure hydrogel and their nanocomposite structure were systematically identified by XRD, FTIR, SEM, TEM, TGA-DTA techniques. The swelling and deswelling properties, which are affected by several factors such as pH (due to the carboxylate groups) and time were studied. The swelling rate improved with the SiO2 nanoparticles. Also, the swelling ratio in NaCl, CaCl2 and AlCl3 salt solutions were investigated and it was found that swelling capacity was 41 and 37 g/g for pure and nanocomposite hydrogel in NaCl solution, respectively. Diclofenac sodium was utilized as a model of drug and the drug release after loaded in the nanocomposite hydrogels was studied. The results revealed essential performances on the subject of physiological-simulated pH media. The maximum cumulative drug releases attained were 90.13% and 79.26% at pH values of 7.4 for nanocomposite and pure hydrogel, respectively. The applicability of drug release kinetic models such as Ritger–Peppas, zero and first-order kinetic models was proved. According to the information obtained from Ritger–Peppas model, the drug release mechanism follows non-Fickian diffusion and indicates an anomalous transport.