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To obtain the optimum conditions for encapsulation of metronidazole in sodium alginate, a response surface methodology (RSM) was used to find out the effect of independent variables (alginate concentration and drug to alginate ratio) on dependent variables including mean particle size, yield, drug loading, and encapsulation efficiency. Furthermore, the effect of alginate concentration on swelling behavior of microbeads was evaluated, and the mechanism of drug release was also studied. On the basis of the results, it can be declared that spherical microbeads with mean particle sizes of 443–665 µm were obtained with process yields, drug loading, and encapsulation efficiencies of almost 79.5%, 54.9%, and 79.9%, respectively. The metronidazole release was found to be 68% in 7 h with a formulation containing the drug to polymer ratio of 2:1. The optimum values for alginate concentration and drug to alginate ratio were determined to be within 1.4% (w/v) and 2.85 (w/w), respectively.

Purpose Photothermal therapy (PTT) is promising for the treatment of tumors due to its advantages including minimally invasive, easy implementation and selective localized treatment. However, single PTT suffers from several limitations, such as constrained light penetration and low delivery efficiency, typically leading to heterogeneous heating and incomplete elimination of cancer cells. Therefore, combination of PTT with other therapies, eg, chemotherapy is desirable in order to achieve synergistic effects in cancer treatment. Methods Here, we designed a new type of TCPP-Iso combined nanoparticle for synergetic therapy for breast cancer. Specifically, photothermal agent tetra(4-carboxyphenyl) porphine (TCPP) and anti-cancer drug isoliensinine (Iso) were encapsulated in PEG-b-PLGA polymeric nanoparticles through a precipitation process. Results The obtained NPs displayed well-controlled size and high stability over time. Tuning TCPP-Iso/polymer ratio, or total concentration of drug and polymers led to increased hydrodynamic radius of NPs from 65 to 108 nm without disturbing the narrow size distribution. Besides, the formed NPs showed a consequently cumulative release of TCPP and of Iso. The temperature elevation ability of both TCPP NPs and TCPP-Iso NPs was TCPP-concentration dependent. Solutions of TCPP NPs that contained equivalent amount of TCPP with respect to TCPP-Iso NPs, presented the same trend and exhibited non-obvious difference in temperature elevation under certain laser power. The viability of MDA-MB-231 cells treated with TCPP-Iso NPs could be inhibited effectively at a relatively mild temperature (42–43°C) compared to the other groups, which may minimize heat damage to the surrounding healthy tissues. Conclusion The results indicate that the TCPP-Iso combined NPs showed hardly any toxicity to normal tissue cell line, but displayed an efficient synergistic effect for killing cancer cells under laser irradiation. Our study demonstrates that the successful combination of TCPP and Iso realized a synergistic therapy effect at a relatively mild temperature, and the insights obtained here shall be helpful for designing new combined PTT agents for cancer treatment., Graphical Abstarct

Nanotechnology mediated drug delivery has been reported to enhance the drug efficacy, bioavailability, reduced toxicity and improve patient compliance by targeting the cells and tissues to elicit the desired pharmacological action. The main aim of the study was to formulate and evaluate Oxiconazole nitrate loaded nanosponges. The oxiconazole nitrate nanosponges were prepared by the emulsion solvent diffusion method by using the different polymers (Ethyl cellulose, β-CD, HP-β-CD). The FTIR test is conducted as the preliminary test, by this test there was no interaction between the drug and polymers. Then nanosponges (NS) were evaluated for particle size, poly dispersive index (PDI), zeta potential, entrapment efficiency andinvitrodrug release. The particle size ranged from 480.60 to 753.46nm, PDI ranged from 0.284 to 0.502, zeta potential from -20.9 to -35.9 mV and entrapment efficiency was ranged from 52.72 to 92.72%. The cumulative percentage release from all nanosponges varied from 73.16 to 97.84 % after 12hours depending upon the drug and polymer ratio and F4 formulation showed highest drug release i.e., 97.84%. The release kinetic studies showed that the release zero order diffusion controlled and the n value (0.713) from the Korsmeyer-Peppa’s model indicated the release mechanism was non-fickian type.

Glycosaminoglycans (GAGs), such as hyaluronic acid (HA) and chondroitin sulfate (CS), have seen widespread adoption as components of tissue engineering scaffolds because of their potent bioactive properties and ease of chemical modification. However, modification of the biopolymers will impair biological recognition of the GAG and reduce the bioactive properties of the material. In this work, we studied how the degree of thiolation of HA and CS, along with other key hydrogel design parameters, affected the physical and bioactive properties of the bulk hydrogel. Although properties, such as the HA molecular weight, did not have a major effect, increasing the degree of thiolation of both HA and CS decreased their biorecognition in experimental analogues for cell/matrix remodeling and binding. Furthermore, combining HA and CS into dual polymer network hydrogels also modulated the physical and bioactive properties, as seen with differences in gel stiffness, degradation rate, and encapsulated cell viability.

The efficient association and controlled release of hydrophilic and aromatic low molecular-weight drugs (HALMD) still remains a challenge due to their relatively weak interactions with excipients and strong affinity to water. Considering that a wide variety of drugs to treat chronic diseases are HALMD, their inclusion in polymeric nanoparticles (NPs) constitutes an attractive possibility by providing to these drugs with controllable physiochemical properties, preventing crisis episodes, decreasing dose-dependent side effects and promoting therapeutic adhesiveness. However, the strong interaction of HALMD with the aqueous medium jeopardizes their encapsulation and controlled release. In this work, the role of the self-assembly tendency of HALMD on their association with the aromatic excipient poly(sodium 4-styrensulfonate) (PSS) to form NPs is studied. For this aim, the widely used drugs amitriptyline (AMT), promethazine (PMZ), and chlorpheniramine (CPM) are selected due to their well described critical aggregation concentration (cac) (36 mM for AMT, 36 mM for PMZ, and 69.5 mM for CPM). These drugs undergo aromatic-aromatic interactions with the polymer, which stabilize their mutual binding, as seen by NMR. The simple mixing of solutions of opposite charged molecules (drug + PSS) allowed obtaining NPs. Importantly, comparing the three drugs, the formation of NPs occurred at significantly lower absolute concentration and significantly lower drug/polymer ratio as the cac takes lower values, indicating a stronger binding to the polymer, as also deduced from the respective drug/polymer dissociation constant values. In addition, the number of formed NPs is similar for all formulations, even though a much lower concentration of the drug and polymer is present in systems comprising lower cac. The obtained NPs are spheroidal and present size between 100 and 160 nm, low polydispersity (≤0.3) and negative zeta potential (from −30 to −60 mV). The association efficiency reaches values ≥ 83% and drug loading could achieve values up to 68% (never evidenced before for systems comprising HALMD). In addition, drug release studies are also significantly influenced by cac, providing more prolonged release for AMT and PMZ (lower cac), whose delivery profiles adjust to the Korsmeyer-Peppas equation. As a novelty of this work, a synergic contribution of drug self-association tendency and aromatic-aromatic interaction between the drug and polymers is highlighted, a fact that could be crucial for the rational design and development of efficient drug delivery systems.

When using polymer injection technology in oilfields, the problem is the separation of oil and water from the produced fluid. Based on the water quality characteristics of the polymer-containing sewage, an improved cyclone air-flotation separation device has been designed and tested in an oilfield wastewater treatment station to investigate the sewage treatment volume and return flow parameters. The effect of polymer ratio, split ratio, and bubble size on the air-flotation cyclone productivity is studied. The results show that when the treatment volume of polymer-containing sewage is 7 m3/h, the reflux ratio and the split ratio are 20% and 11%, respectively, the bubble size is large, the oil content in the wastewater after treatment decreases from 500.6 to 45.75 m3/h, and the suspended solids content decreases from 601.7 to 206.1 m3/h. Finally, the test results show that the wastewater after treatment complies with the requirements for the further filtration process.

Isradipine belong to dihydropyridine (DHP) class of calcium channel blockers (CCBs). It is used in the treatment of hypertension, angina pectoris, in addition to Parkinson disease. It goes under the BCS class II drug (low solubility-high permeability). The drug will experience extensive first-pass metabolism in liver, therefore, oral bio-availability will be approximately15 to 24 %. The aim of this study was to formulate and optimize a stable nanoparticles of a highly hydrophobic drug, isradipine by anti-solvent microprecipitation Method to achieve the higher in vitro dissolution rate, so that it will be absorbed by intestinal lymphatic transport in order to avoid hepatic first-pass metabolism and improve drug bioavailability. Twenty one formulas of Isradipine nanoparticles were prepared by antisolvent precipitation method utilizing one of these polymers (Poloxamer 188, PVP-k30, HPMC E5, PVA, Poloxamer 407, and Soluplus) at different drugs: polymer ratios. The polymer type, the drug to polymer ratio, ultrasonication power and the effect of addition of co-stabilizer on the particle size, and polydispersity index (PDI) were investigated. Among all the prepared nanoparticles formulas, formula (F9) which contain Soluplus as a stabilizer at polymer: drug ratio of (1:0.75) and solvent: antisolvent ratio of (1:9) was considered as the optimum formula which shows good evaluation parameters in addition to the increment in the solubility to about 10 times than that of the pure drug. The investigations of the drug–excipients compatibility studies by FTIR and DSC, crystalline state by P-XRD, surface morphology by SEM were done. Moreover, the analysis by DSC and SEM of the nanoparticles of the selected formula (F12) indicate a reduction in the crystallinity and amorphization of the drug. It can be concluded that the dissolution rate of Isradipine was significantly increased through particle size reduction to nanosize.

We present that high birefringent nematic liquid crystal, 4-n-pentyl-4'-cyanobiphenyl, was incorporated into the polyacrylonitrile precursor which has a strong polar cyano group so as to produce electrospun nano-fibers, as the first time. Optical textures of nano-fibers were taken by polarized optical microscopy with different angles to determine the orientation degree of liquid crystal molecules in the center of the fiber. The molecules of liquid crystal self-ordered within the core of the fiber. Variation in morphology of liquid crystal/polymer nano-fibers were examined by utilizing both scanning electron microscopy and polarized optical microscopy depending on liquid crystal concentration in precursor and application voltage during electrospinning. Morphology of nano-fibers was significantly affected by electrospinning parameters and liquid crystal/polymer ratio. To understand phase separation and thermal stability of nano-fibers, calorimetric and thermogravimetric analyses were performed.

Aims: The aim of this work is the formulation of Eudragit RL100 polymeric microsponges. The Microsponge Delivery System is a patented technique in which there is a polymeric system consisting of porous particles. Methodology: The ratio of Diclofenac sodium and eudragit RL100 varied from 1:1 to 13: 1 to formulate microsponge. Dichloromethane was used as internal phase and polyvinylalcohol was used as an external phase. The formed microsponges were characterized for particle size, entrapment efficiency, drug content, in vitro drug release and SEM. Results: With increase in drug: polymer ratio there is increase in production yield from 20.04% to 72.14%, and entrapment efficiency from 20.11% to 70.77%. Drug content of formed microsponge varied between 50.18% to 91.09% whereas particle size ranged from 1.41 µm to 17.66 µm. Microsponge formulations F3, F4 and F5 showed desired particle size hence studied for further evaluation. Formulation F3, F4 and F5 showed controlled release of 89.54%, 98.5% and 98.76% respectively up to 6 hr. F3 showed more controlled release at the end of 6 hr. The drug release from microsponges was best fitted to Higuchi’s diffusion kinetics for all microsponge formulations with non-Fickian diffusion mechanism. The formed microsponge particles have spherical porous structure. Conclusion: Study showed significance of Microsponge Delivery System for ophthalmic administration.

Silymarin, a flavonolignan, derived from Silybum marianum, family Asteraceae has long been used as a hepatoprotective remedy. Silymarin has cytoprotective activities due to its antioxidant property and free radical scavenging activity. The pharmacokinetic studies of past three decades revealed that silymarin has poor absorption, rapid metabolism especially by Phase II metabolism and ultimately poor oral bioavailability. Quercetin, a flavonoid present in edible vegetables and fruits, It is a potent antioxidant and shows a wide range of biological functions. Quercetin improves blood levels and efficacy of number of drugs since it is P-Glycoprotein inhibitor and also inhibits drug metabolizing enzymes. Both silymarin and quercetin were, poorly soluble in the water shows low bioavailability. The advanced type of formulation like polymeric nanoparticles (PNPs) can be successfully utilised for bioavailability enhancement and targeting the Silymarin-quercetin to hepatocytes. A controlled release PNPs of silymarin-quercetin were prepared by spontaneous emulsification solvent diffusion (SESD) method using Poly Lactic-co-Glycolic Acid (PLGA) as biodegradable polymer, D-alpha-tocopheryl poly (ethylene glycol) 1000 succinate (TPGS) used as a solubilizer, as an emulsifier. TPGS as an emulsifier and further as a matrix material blended with PLGA was used to enhance the encapsulation efficiency and improve the drug release profile of nanoparticles. Different formulations with various drug: polymer ratios and volume and concentration of surfactant, centrifugation time were evaluated. The effect of formulation parameters such as drug/polymer ratio, volume and surfactant content were evaluated. The surface morphology and size of the nanoparticles were studied by scanning electron microscopy (SEM) Transmission electron microscopy (TEM). Drug encapsulation efficiency and in vitro drug release profiles of nanoparticles were determined using UV spectrophotometry. The nanoparticles prepared with combination of both the drugs in this study were spherical with size range of 100–200 nm. It was shown that TPGS was a good emulsifier for producing nanoparticles of hydrophobic drugs and improving the encapsulation efficiency and drug loading and drug release profile of nanoparticles. Although the amount of the TPGS used had a significant effect on the nanoparticle size and morphology, the drug loading and release profile of nanoparticles

Background Present investigation for research was to develop matrix-type transdermal drug delivery system of flurbiprofen (FBP) with the various ratio of matrix polymers (hydrophilic and hydrophobic), the concentration of plasticizer and natural penetration enhancer by Box–Behnken statistical design to investigate the combined outcome of selected independent variables for effective management of rheumatoid arthritis. The influence of a binary mixture of polymers, plasticizer and penetration enhancer on physicochemical considerations including thickness, tensile strength, percent elongation, weight variation, percent moisture content, percent moisture uptake, water vapour transmission rate, folding endurance, drug content, in vitro drug dissolution study and then ex vivo drug permeation study was evaluated. Results The study demonstrated that the tensile strength of films improved by matrix polymer ratio and to a slighter gradation in the rise of plasticizer and natural penetration enhancer. Ex vivo drug permeation study was accompanied via excised porcine skin as a permeation barrier in Franz diffusion cell. Ex vivo drug permeation study indicated that matrix polymer ratio (HPMC K15M:ERL100) at 3:1 and natural penetration enhancer (d-limonene) at highest concentration 7.5% w/w containing formulation FBPT7 delivered maximum flux and supplementary improved the permeation of drug. The result of the skin irritation test revealed that the developed formulation is free from any type of skin irritation effects like erythema and oedema. Conclusion Based on the findings of this research, it can be established that a well-controlled release and very effective skin penetration of the drug was accomplished by the film FBPT7 in the existence of permeation enhancers for prolonged periods.

Egg white protein (EWP) was one of the high-quality protein sources and widely used in the food industries because of excellent emulsifying, gelling, and foaming properties. Polysaccharides as a natural biological macromolecule have been used to improve the functional properties of EWP. The electrostatic interaction was the main driving force between EWP and polysaccharides. However, protein-polysaccharides complexes were susceptible to environmental factors including pH, ionic strength, polymer ratio, and temperature. In this paper, the functional properties of EWP were summarized. More importantly, the effects of polysaccharides on the functional properties of EWP were highlighted and reviewed referring to emulsifying, foaming, and gelling properties. The impact of environmental factors on the protein-polysaccharides interaction were also discussed. This paper leaded to enrich research systems of protein-polysaccharides interaction and provided information for the development of new egg white-derived foods.

This investigation is to find a prolonged or delayed drug release system, exclusively for the treatment of hepatitis‐B to reduce the side effects, which arise when conventional solid dose forms are administered. To pursue this goal, lamivudine‐loaded Eudragit‐coated pectin microspheres have been formulated employing water/oil (W/O) emulsion evaporation strategy. The formulation was optimised using a 34 factorial design. A drug to polymer ratio of 1:2, the surfactant of 1 ml, the volume of 50 ml of processing medium with a stirring speed of 2500 rpm were found to be the optimal parameters to obtain the lamivudine‐loaded Eudragit‐coated pectin microspheres formulation with a high drug entrapment efficiency of 89.44% ± 1.44%. The in vitro release kinetics of lamivudine was a suitable fit to the Higuchi model, indicating a diffusion‐controlled release with anomalous transport. The obtained microspheres were then subjected to different characterisation studies, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD). The results of this study clearly indicate that Eudragit‐coated pectin microspheres could be the promising controlled release carriers for colon‐specific delivery of lamivudine in the presence of rat cecal content.

In this study, ionically crosslinked beads of sodium alginate (NaAlg) and methylcellulose (MC) were prepared as semi-interpenetrating polymer networks (semi-IPN) in the size range of 1.97 ± 0.09–1.22 ± 0.13 mm by crosslinking with FeCl3 and loaded with ibuprofen (IBU), which is a nonsteroidal anti-inflammatory drug. The highest 93.33% entrapment efficiency of IBU was achieved, and the drug release behaviors, mean particle size, and entrapment efficiency of beads were investigated in terms of the polymer composition, a ratio of ibuprofen to polymer, exposure time to crosslinker, and concentration of the crosslinking agent. Semi-IPN formulations prepared were also characterized using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), X-ray Diffraction (X-RD), and scanning electron microscopy (SEM). It was observed that IBU-loaded beads displayed better release performance with an increase amount of NaAlg in the structure. Finally, the optimum IBU release was obtained as 93.9% for beads containing 66.7% (w/w) NaAlg, 33.3% (w/w) MC, IBU/polymer ratio of 1/4, FeCl3 concentration of 0.1 M, and crosslinking time of 90 min. The in vitro release rate was fitted to five empirical equations, and the diffusion exponent n, which indicated that the release mechanism of IBU from beads followed the Anomalous and Case II transport mechanism.

This study aims to develop amorphous solid dispersion (ASD) of lumefantrine with a cost-effective approach of spray anti-solvent precipitation. Four acidic polymers, hydroxypropylmethylcellulose phthalate (HPMCP), hydroxypropylmethylcellulose acetate succinate (HPMCAS), poly(methacrylic acid–ethyl acrylate) (EL100) and cellulose acetate phthalate (CAP) were studied as excipients at various drug-polymer ratios. Of the studied polymers, satisfactory physical stability was demonstrated for HPMCP- and HPMCAS-based ASDs with no observed powder X-ray diffraction peaks for up to 3 months of storage at 40 °C/75% RH. HPMCP and HPMCAS ASDs also achieved greater drug release levels in the dissolution study than other polymers. The HPMCP-based ASDs with a drug:polymer ratio of 2:8 exhibited a maximum drug release of 140 μg/mL for up to 2 h, which is significantly higher than the currently marketed formulation of Coartem® (

We report herein the first lithium anthraquinoid catalyst able to produce polylactide at room temperature starting from both L- and rac-lactide in the absence of any other initiator. The new lithium-based system is selective towards cyclic polymers, having narrow dispersity and weight-average molecular weights ranging from 49.5 to 137.6 kDa. The cyclic structure of the PLA generated from the lithium catalyst has been determined by a combination of 1H NMR and DRIFT spectroscopy techniques and MALDI-TOF mass spectrometry. DFT calculations point to lithium aggregation as the key feature of the catalyst controlling the linear : cyclic polymer ratio. Molar mass distributions and dispersities were obtained through diffusion NMR experiments combined with inverse Laplace transform algorithms and compared with those obtained by SEC as the most established method.

Aim: The aim of the present study is to prepare and evaluate nanoparticles containing Simvastatin using chitosan as the polymer. Methods: The Simvastatin loaded nanoparticles were prepared by ionic gelation of chitosan with tripolyphosphate anions. Nanoparticles of different core: coat ratio were formulated and evaluated for process yield, loading efficiency, particle size, zeta potential, in vitro drug release, kinetic studies and stability studies. Results: The prepared nanoparticles were white, free flowing and spherical in shape. The infrared spectra showed stable character of Simvastatin in the drug-loaded nanoparticles and revealed the absence of drug polymer interactions. The chitosan nanoparticles have a particle diameter ranging approximately 132.1±5.60 to 774.8±2.60nm and a zeta potential 11.93 to 43.23mV. The formulation with the initial Simvastatin concentration of 0.5 mg/ml provided the highest loading capacity. The in vitro release behavior from all the drug loaded batches were found to follow zero order and provided sustained release over a period of 10 h. No appreciable difference was observed in the extent of degradation of product during 90 days in which nanoparticles were stored at various temperatures. Conclusion: The best-fit release kinetics was achieved with zero order mechanism. The release of Simvastatin was influenced by the drug to polymer ratio and particle size. These results indicate that Simvastatin nanoparticles could be effective in sustaining drug release for a prolonged period.

Potassium permanganate (KMnO4) has been used widely as an oxidant for remediation of contaminated soil and water systems. The present study evaluates the release of this oxidant from Polycaprolactone (PCL) polymer as part of a patented controlled release process (CRP) to be applied for targeted removal of contaminants from water. KMnO4 was encapsulated into PCL at a 1:5 oxidant to polymer ratio and placed in batch reactor systems with reagent water to be evaluated over a 96 hour period. SEM images showed that over time, the number of cavities and their sizes increased on the waxy surface of the PCL polymer. The experimental data from the release of KMnO4 from PCL was found to fit non-Fickian diffusion model after dissolution (R2 = 0.93) similar to other systems that describe the dispersal of other oxidants from wax matrices. In addition, the model parameters for data of this present study were also found to be comparable to previous release studies with the same oxidant encapsulated in different wax matrices at similar ratios. Overall, the similarity of release data between the diversity of polymers shows that the controlled release biodegradable polymer utilizing PCL provides effective release of the KMnO4 with the added benefit biodegradable nature of PCL.

Aims: To prepare lamivudine (LAM)-loaded-nanoparticles (NPs) that can be used in lung cancer treatment. To change the antiviral indication of LAM to anticancer. Background: The development of anticancer drugs is a difficult process. One approach to accelerate the availability of drugs is to reclassify drugs approved for other conditions as anticancer. The most common route of administration of anticancer drugs is intravenous injection. Oral administration of anticancer drugs may considerably change current treatment modalities of chemotherapy and improve the life quality of cancer patients. There is also a potentially significant economic advantage. Objective: To characterize the LAM-loaded-NPs and examine the anticancer activity. Methods: LAM-loaded-NPs were prepared using Nano Spray-Dryer. Properties of NPs were elucidated by particle size (PS), polydispersity index (PDI), zeta potential (ZP), SEM, encapsulation efficiency (EE%), dissolution, release kinetics, DSC and FT-IR. Then, the anticancer activity of all NPs was examined. Results: The PS values of the LAM-loaded-NPs were between 373 and 486 nm. All NPs prepared have spherical structure and positive ZP. EE% was in a range of 61-79%. NPs showed prolonged release and the release kinetics fitted to the Weibull model. NPs structures were clarified by DSC and FT-IR analysis. The results showed that the properties of NPs were directly related to the drug:polymer ratio of feed solution. NPs have potential anticancer properties against A549 cell line at low concentrations and non-toxic to CCD 19-Lu cell line. Conclusion: NPs have potential anticancer properties against human lung adenocarcinoma cells and may induce cell death effectively and be a potent modality to treat this type of cancer. These experiments also indicate that our formulations are non-toxic to normal cells. It is clear that this study would bring a new perspective to cancer therapy.

Ondansetron HCl (OND) is a potent antiemetic drug used for control of nausea and vomiting associated with cancer chemotherapy. It exhibits only 60 – 70 % of oral bioavailability due to first pass metabolism and has a relative short half-life of 3-5 hours. Poor bioavailability not only leads to the frequent dosing but also shows very poor patient adherence. Hence, in the present study an approach has been made to develop OND nanoparticles using eudragit® RS100 and eudragit® RL100 polymer to control release of OND for transdermal delivery and to improve patient compliance. Six formulas of OND nanoparticles were prepared using nanoprecipitation technique. The particles sizes and zeta potential were measured using zeta-plus analyzer. The particle morphology was also studied using scanning electron microscopy (SEM). The in-vitro release of the drug from the nanoparticles was carried out in phosphate buffer saline pH 7.4. The particle size of the prepared NPs were in nano size which ranged from (95.34 to 275.84 nm) with positive zeta potential. The drug entrapment efficiency was varied with the drug polymer ratio from 41.87% to 78.45%. The SEM showed uniform shape and regularly distributed particle sizes. The in-vitro drug release study exhibited the sustained release of OND with burst release. The cumulative percentage released after 12 hr. were between were 77.89 and 96.01%. Also the transdermal permeation study show that nanoparticles permeate more efficiently than aqueous solution of the drug through the skin by approximately two fold. OND nanoparticles were prepared successfully using nanoprecipitation method. The controlled drug release aimed for transdermal drug delivery could be obtained by using eudragit RS100 and eudragit RL100 polymers which can reduce dosing frequency, decrease side effects and improve patient compliance.

The objective of the present learns to improve solubility and dissolution of Olmesartan Medoxomil (OM) by improving water solubility by reliable dispersion methods using fusion method (FM) and solvent evaporation (SE) method via hydrophilic polymers PEG 6000 and PVP K30 in different ratios. Preformulation studies of OM: polymers were carried using DSC and FTIR proves that it is stable without any extra peaks, which implies no interaction among the drug and carrier. For OM in FM drug: polymer ratio was maintained in a range 1:1, 1:3, 1:5 and 1:7 w/w ratio of OM to PEG 6000 and coded as SDOM1, SDOM2, SDOM3 and SDOM4 whereas for SE method OM to PVP K30 ratio was maintained in a range of 1:1, 1:3, 1:5 and 1:7 w/w ratio and coded as SDOM5, SDOM6, SDOM7 and SDOM8. SDOM3 by FM and SDOM7 by SE method resulted in the highest production yield. The solubility studies have shown improved drug solubility compared with a pure drug in all medium. Percentage of drug content, flowability characters like the angle of repose and carr's index, bulk density, Hausner's, tapped density were within acceptable limits. In vitro drug release in the intestinal gastric medium of pH 1.2 was improved significantly when compared with pure drug. SDOM3 and SDOM7, selected for accelerated stability studies, had no significant change in physical parameters, drug content, with little changes in the in vitro drug release pattern. Hence solubility and dissolution rate of OM is increased by using the PEG 6000 and PVP K30 polymers.

This study reports on the preparation, optimization, and in vitro evaluation of micronized solid dispersions containing Polyethylene Glycol 4000 (PEG4000) and aspirin to increase the dissolution rate of aspirin in water. To achieve this goal, aspirin/PEG4000 composites were prepared and characterized by applying a solid dispersion method with subcritical CO2. Employing response surface methodology (RSM) using the Box-Behnken design (BBD), the effects of different variables including pressure, concentration, drug/polymer ratio, and their interactions on drug content and yield of production were investigated. The closeness between the measured and predicted responses with R2>0.99 demonstrated the validity of the statistical analysis. The optimal formulation obtained from RSM is at a pressure of 63.5 bar, concentration of 0.17 g/gSolution, and drug/polymer ratio of 1. Under the optimized condition, the yield of production and drug content % reached 91.5% and 54.5%, respectively. Dissolution tests carried out in buffer phosphate solution at pH 7.4 showed a significant improvement in dissolution rate, with a rate approximately seven times faster than unprocessed aspirin. In addition, the in vitro drug release profile of produced composites showed an initial burst release of more than 80% in the first 2 min.

Objective: Mebeverine hydrochloride is an antispasmodic agent that has a direct musculotropic action on the smooth muscles of the gastrointestinal tract; especially the colon.Therefore, the current study aimed at formulating and optimizing colon targeted mebeverine hydrochloride microspheres for treatment of chronic gastrointestinal disorder. Methods: Mebeverine hydrochloride-loaded chitosan microspheres were formulated adopting emulsion cross-linking method using glutaraldehyde as a cross linking agent. A 33 Box Behnken design was utilized in formulating the microspheres and investigating the effect of different formulation factors such as drug: polymer ratio (X1), stirring speed (X2) and the surfactant concentration (X3) on particle size (Y1), the entrapment efficiency percentage (Y2) and the cumulative release percentage of mebeverine hydrochloride after 8 h (Y3). Results: The particle size and entrapment efficiency were significantly affected by tested formulation parameters. The release of mebeverine hydrochloride from optimized formula was pH dependent. In simulated gastric fluid, less than 10% of entrapped mebeverine hydrochloride was released, while, a relatively high amount of the drug (> 65%) was released in simulated colonic fluid (pH 7.4). The in vivo pharmacokinetic study revealed that the optimized formula of microspheres exhibited increased oral absorption of mebeverine hydrochloride, compared to free drug (Cmax 168.51±20.05 ng/ml vs. 126.45±29.46 ng/ml, respectively). In addition, the optimized formula exerted a remarkably higher systemic bioavailability, compared to the free drug. Conclusion: These results underscore the applicability of cross-linked chitosan microspheres as a promising carrier for colon targeted delivery of mebeverine hydrochloride for treating diseases associated with the colon such as irritable bowel syndrome.

Herein, we elaborated on the feasibility of coupling polyvinyl chloride with tin aluminium molybdophosphate to form composite membranes that facilitate enhanced electro-transport properties. Additionally, the effect of appropriate material selection on attaining excellent stability and selectivity of a membrane was investigated, and the membrane with 25% polymer had the best results in terms of improved ion exchange capacity, water uptake, porosity, membrane potential, and chemical and thermal stabilities. The electrochemical properties of the membrane that had the most stable polymer ratio were evaluated according to the membrane potential and fixed charge density measurements using different 1:1 ratios of electrolytes with various concentrations (1 M to 0.01 M). The membrane potential, transport number, and mobility ratio of the electrolytes from the highest to lowest were NaCl > KCl > NaNO3 > KNO3.The measured membrane potentials closely agreed with the theoretical predictions from a mathematical model called the Toerell, Maeyer, and Siever (TMS) model, confirming efficiency and selectivity.

The ultrafine fibers based on mixtures of biodegradable polyesters (poly(3-hydroxybutyrate) (PHB) and polylactide (PLA)) are produced via electrospinning. The dependence of the mixed fiber structure on composition is shown by optical microscopy. Using the probe technique of electron paramagnetic resonance (EPR) and differential scanning calorimetry (DSC) methods, the structure of the crystalline and amorphous regions of the fibers is analyzed. The introduction of 10–70% of PHB into the PLA matrix leads to a sharp increase in molecular mobility, but the radical concentration in the amorphous regions decreases dramatically. The increase in the PHB concentration in the mixture over 70% results in a decrease in molecular mobility. Studies on the polymer matrix state for the first time allow one to interpret at the supramolecular level the effects of ozone and ultraviolet (UV) radiation on the structural and dynamic characteristics of PHB/PLA fibers. It is shown that the correlation time of the radical in mixtures is minimal and does not depend on the polymer ratio in the fiber and the time of exposure to ozone and UV radiation.

Background:Developing a new excipient and obtaining its market approval is an expensive, time-consuming and complex process. Compared to that, the co-processing of already approved excipients has emerged as a more attractive option for bringing better characteristic excipients to the market. The application of the Design of Experiments (DoE) approach for developing co-processed excipient can make the entire process cost-effective and rapid.Objective:The aim of the present investigation was to demonstrate the applicability of the DoE approach, especially 32 full factorial design, to develop a multi-functional co-processed excipient for the direct compression of model drug - cefixime trihydrate using spray drying technique.Methods:The preliminary studies proved the significant effect of atomization pressure (X1) and polymer ratio (microcrystalline cellulose: mannitol - X2) on critical product characteristics, so they were selected as independent variables. The angle of repose, Carr’s index, Hausner’s ratio, tensile strength and Kuno’s constant were selected as response variables.Result:The statistical analysis proved a significant effect of both independent variables on all response variables with a significant p-value < 0.05. The desirability function available in Design Expert 11® software was used to prepare and select the optimized batch. The prepared co-processed excipient had better compressibility than individual excipients and their physical mixture and was able to accommodate more than 40 percent drug without compromising the flow property and compressibility.Conclusion:The present investigation successfully proved the applicability of 32full factorial design as an effective tool for optimizing the spray drying process to prepare a multi-functional co-processed excipient.

Aim: This study was focused on the formulation of the multi-unit extended-release peroral delivery device of lamotrigine for better management of epilepsy. Background: The single-unit extended-release peroral preparations often suffer from all-or-none effect. A significant number of multi-unit delivery systems have been reported as a solution to this problem. But most of them are found to be composed of synthetic, semi-synthetic or their combination having physiological toxicity as well as negative environmental impact. Therefore, fabrication and formulation of multi-unit extended-release peroral preparations with natural, non-toxic, biodegradable polymers employing green manufacturing processes are being appreciated worldwide. Objective: Lamotrigine-loaded extended-release multi-unit beads have been fabricated with the incorporation of a natural polysaccharide Cassia fistula seed gum in calcium-cross-linked alginate matrix employing a simple green process and 23 full factorial design. Methods: The total polymer concentration, polymer ratio and [CaCl2] were considered as independent formulation variables with two different levels of each for the experiment-design. The extended-release beads were then prepared by the ionotropic gelation method using calcium chloride as the crosslinkerions provider. The beads were then evaluated for drug encapsulation efficiency and drug release. ANOVA of all the dependent variables such as DEE, cumulative % drug release at 2h, 5h, 12h, rate constant and dissolution similarity factor (f2) was done by 23 full factorial design using Design-Expert software along with numerical optimization of the independent variables in order to meet USP-reference release profile. Results: The optimized batch showed excellent outcomes with DEE of 84.7 ± 2.7 (%), CPR2h of 8.41± 2.96 (%), CPR5h of 36.8± 4.7 (%), CPR12h of 87.3 ± 3.64 (%) and f2 of 65.9. Conclusion: This approach of the development of multi-unit oral devices utilizing natural polysaccharides might be inspiring towards the world-wide effort for green manufacturing of sustained-release drug products by the QbD route.

Photocatalysis is a promising technology used in wastewater treatment. However, the practical application of this approach has been hindered by several factors. One issue is the aggregation of the photocatalyst in solution which leads to significant decrease in catalytic efficiency. Recent innovations in photochemical research have geared towards improving the colloidal stability of well-known photocatalysts such as titanium dioxide (TiO2). In this study, a simple method of imparting colloidal stability to TiO2, through one-pot photo-polymerized polypyrrole (PPy) nanoparticle coatings were demonstrated. The resulting TiO2-PPy (TP) dispersions exhibited excellent resistance to aggregation as evident in their uniform particle size distribution (diameter = 81.40 ± 6.58 nm, polydispersity index = 0.412 ± 0.037) and stable zeta-potential values (ζ = 33.15 ± 4.35). The optimum TiO2 to polymer ratio also resulted to significant lowering in band-gap energy (from 3.54 eV to 3.15 eV) which is an indicator of improved photocatalytic properties. Photodegradation of a model pollutant, methyl orange (MO) performed at optimal lightning condition and 4TP dosage showed 35% /hour photocatalytic efficiency. Lastly, kinetic studies suggest that the catalytic performance is dependent on the pollutant concentration as shown by a second-order MO degradation with rate constant of 306.856 x 10-7 M-1 s-1 and proposed rate law of R = k [MO]2. The study had also indicated the chemical conversion of MO to CO2 by measuring about 43% decrease in total organic carbon in an hour.

This study investigates the fabrication, characterization and optimization of Linum usitatissimum mucilage (LSM) with sodium alginate mucoadhesive microspheres loaded metformin HCl, a sustained release dosage form prepared by ionic gelation technique. The effect of changing the polymer ratio with drug was studied for drug encapsulation efficiency and in vitro drug release for 12 h. Drug entrapment efficiency of all formulations was in the range of 77.93 ± 3.67 to 92.25 ± 4.08% with sustained release of 80 ± 0.12% to 88 ± 0.33% for 12 h. It followed Korsmeyers Peppas model (R2 = 0.9786–0.9964) with super case II transport mechanism. Average microsphere size of all formulations was within the range of 817–911 μm. SEM, FTIR were also characterized and swelling behavior of microspheres was affected by pH of buffer medium. These microspheres also showed good mucoadhesivity in wash off test. The optimized LSM-alginate mucoadhesive microspheres containing metformin HCl demonstrated significant hypoglycemic effect in alloxan-induced diabetic rats for prolonged period of time.

Purpose The objective of this study was to compare different techniques to enhance the solubility and dissolution rate, and hence the bioavailability of candesartan cilexetil. Methods To achieve this target, various techniques were employed such as solid dispersions, inclusion complexes, and preparation of candesartan nanoparticles. Following the preparations, all samples were characterized for their physicochemical properties, and the samples of the best results were subjected to further bioavailability studies. Results Results of dissolution studies revealed an increase in the dissolution rate of all samples. The highest dissolution rate was achieved using solid dispersion of the drug with PVP K-90 (1:4). Physicochemical investigations (XR, DSC, and FT-IR) suggested formation of hydrogen bonding and changing in the crystalline structure of the drug. Regarding the inclusion complexes, more stable complex was formed between HP-β-CD and CC compared to β-CD, as indicated by phase solubility diagrams. Antisolvent method resulted in the preparation of stable nanoparticles, as indicated by ζ potential, with average particle size of 238.9 ± 19.25 nm using PVP K-90 as a hydrophilic polymer. The best sample that gave the highest dissolution rate (CC/PVP K-90 1:4) was allowed for further pharmacokinetic studies using UPLC MS/MS assay of rabbit plasma. Results showed a significant increase in the bioavailability of CC from ~15% to ~48%. Conclusion The bioavailability of CC was significantly improved from ~15% to ~48% when formulated as SDs with PVP K-90 with 1:4 drug:polymer ratio.

The effects of adding multi-walled carbon nanotubes (MWCNTs) on the solid-state rheological and dielectric properties of blends of poly(methyl methacrylate) (PMMA) and low-density polyethylene (LDPE) were studied as a function of varying polymer ratio. Dynamic mechanical thermal analysis (DMTA) was performed in torsion mode, on the blends and their composites with MWCNTs. For a PMMA/LDPE blend with a ratio of 80:20, the evolution of the loss tangent with temperature showed a single thermal event, associated with the glass transition (Tg) of PMMA, confirming that co-continuity has not been achieved. Upon loading with 2 wt.% MWCNTs, a decrease in the magnitude of this peak is observed. Even though the MWCNTs preferentially locate in the polymer phase first to melt, i.e., LDPE, selective solvent extraction on this sample demonstrated that some of the MWCNTs are trapped in the major phase, PMMA. Moreover, DMTA measurements also revealed the formation of a “rheological” percolated network at ~ 3.5 wt.% MWCNTs in PMMA/LDPE blends with polymer ratios of 50:50 and 20:80, but not in 80:20. In contrast, for the same MWCNT concentration, a 80:20 blend displayed a well-developed AC conductivity plateau at low frequencies and highly enhanced dielectric properties, as a consequence of the high concentration of micro-capacitors formed by polymer films sandwiched by nanotubes within the LDPE phase, as proven from atomic force microscopy observations.

Nacre-mimetic nanocomposites based on high fractions of synthetic high-aspect-ratio nanoclays in combination with polymers are continuously pushing boundaries for advanced material properties, such as high barrier against oxygen, extraordinary mechanical behavior, fire shielding, and glass-like transparency. Additionally, they provide interesting model systems to study polymers under nanoconfinement due to the well-defined layered nanocomposite arrangement. Although the general behavior in terms of forming such layered nanocomposite materials using evaporative self-assembly and controlling the nanoclay gallery spacing by the nanoclay/polymer ratio is understood, some combinations of polymer matrices and nanoclay reinforcement do not comply with the established models. Here, we demonstrate a thorough characterization and analysis of such an unusual polymer/nanoclay pair that falls outside of the general behavior. Poly(ethylene oxide) (PEO) and sodium fluorohectorite form nacre-mimetic, lamellar nanocomposites that are completely transparent and show high mechanical stiffness and high gas barrier, but there is only limited expansion of the nanoclay gallery spacing when adding increasing amounts of polymer. This behavior is maintained for molecular weights of PEO varied over four orders of magnitude and can be traced back to depletion forces. By careful investigation via X-ray diffraction and proton low-resolution solid-state NMR, we are able to quantify the amount of mobile and immobilized polymer species in between the nanoclay galleries and around proposed tactoid stacks embedded in a PEO matrix. We further elucidate the unusual confined polymer dynamics, indicating a relevant role of specific surface interactions.

The current study involves development of novel tamarind seed gum - alginate complex microspheres for sustained release of dalfampridine by using Central Composite design in combination with response surface methodology. Polymer ratio (A), agitation speed (B) and concentration of CaCl2 (C) were selected as independent variables. Dalfampridine loaded microspheres are prepared by ionotropic gelation technique and were evaluated for responses. The software numerical optimization process, surface and contour plots predicted the level of independent variables A, B and C (2.6, 800.412 rpm and 1.1%w/w respectively), for maximum response of drug entrapment efficiency (86.09%), controlled release of drug at 1 h, 6 h, 12 h (29.84%, 67.92%, 86.42%) and optimized particle size (613.212 μm) respectively. Low magnitude of relative error for the optimized formulation confirms the validation of model. Optimized formulation was characterized for compatibility by Fourier Transform infrared spectroscopy and Differential scanning calorimetry. The drug release data was best fitted by first order and Higuchi square root model with non-Fickian diffusion kinetics. Therefore, such an attempt of fabrication of dalfampridine multi-particulates system by using tamarind seed gum and sodium alginate may be useful in a better way, for sustaining the release of drug over 12 h.

Ceftriaxone, a third generation cephalosporin antibiotic is an important antibiotic used in the treatment of invasive infections caused by the certain bacteria such as the penicillin-resistant microorganisms like Staphyloccocus aureus, strains of S. pneumonia, S. aureus and Enterobacteriaceae , particularly among E. coli. There is increasing antimicrobial resistance of Ceftriaxone in particular against these strains of bacteria. This study has been conducted to formulate, evaluate and optimize chitosan coated ceftriaxone loaded microparticles with better efficacy and also observes the MIC against strains of bacteria. Emulsion crosslinking method was used for the formulation of microparticles of ceftriaxone by using chitosan as a polymer and glutraldehyde as a cross linking agent which is optimized by using Box-Behnken Design. Three independent variables were taken; effect of drug and the polymer ratio, effect of the stirring speed and effect of crosslinking agent and dependent variables were microparticles entrapment efficiency and the In vitro drug release. Following optimization of the formulations, physical characterization as well as entrapment efficiency and ultimately in-vitro evaluation was performed. Physical characterization include optical microscopy, SEM and DLS to check there physical properties. The method used for the formulation of microparticle had the optimum entrapment efficiency of 61.7% which was increase with the increase in the addition of the more amount of chitosan and glutraldehyde and method also achieved the good in vitro release. MIC studies of microparticles were done against Klebsiella pneumonia, Staphylococcus aureus, Streptococcus mutans, Escherichia coli and it was found that the formulations showed decrease in MIC.

Alpha-mangostin is a xanthone compound isolated from the mangosteen plant (Garcinia mangostana L.), which has various pharmacological activities. However, in its utilization alpha-mangostin is unstable and shows low solubility in the oral delivery system. Nanoparticles can deliver specific drugs to their workplace and increase the solubility. The objectives of this study were to create and characterize the alpha-mangostin nanoparticles based on chitosan and Eudragit® S 100. The nanoparticles were made by the ionic gelation method with comparisons core: Coating FI (1:2), FII (1:1), and FIII (2:1). Nanoparticles powder obtained using the spray pyrolysis method. Characterization using Fourier transform infrared indicates that the nanoparticles have been coated properly, and no damage occurred in the formula. The particle sizes for FI, FII, and FII are 373.381 ± 138.023 nm, 398.333 ± 184.977 nm, and 326.567 ± 130.366 nm, respectively, with a smooth surface. The entrapment efficiency value of FI, FII, and FIII are, respectively, 99.7692%, 99.6535%, and 99.476%. Alpha-mangostin was successfully encapsulated in chitosan-tripolyphosphate polymer by ionic gelation method and then coated with Eudragit S 100. Alpha-mangostin chitosan-eudragit nanoparticles (core: Polymer ratio of 1:2) yielded more entrapment efficiency.

Novel formulations of donepezil (DNP)-loaded microspheres based on a bio-degradable polymer of poly(lactic-co-glycolic acid) (PLGA) with a one-month duration of effect were developed, aimed at reducing dosing frequency and adverse effects and improving patient adherence. The spherical and monodispersed DNP-loaded microspheres were precisely fabricated by the Inventage Lab Precision Particle Fabrication method (IVL-PPFM®) based on micro-electromechanical systems (MEMS) and microfluidic technology. The types of polymers and end-groups, the drug/polymer ratio (DPR), and the routes of administration for DNP were studied to ensure an effective concentration and desired duration. Laser-light particle size analysis and scanning electron microscopy were used to characterization. Also, non-clinical animal models of beagle dogs are used to optimize DNP formulations and evaluate their pharmacokinetic properties. The PK results showed that the DPR was a critical factor in determining the exposure level and duration of DNR release. Furthermore, the lactide ratio, which varied depending upon the type of polymer, determined the hydrophobic interaction and was also an important factor affecting the desired DNP release. Since DNP shows a large inter-species variation between dogs and humans, PK modeling and simulation of the reference drug (i.e., Aricept®) and DNP-loaded microspheres were used for formulation development to overcome and interpret these variations. In addition, the developed PK model was extrapolated to humans using the estimated PK parameter and published clinical pharmacology data for DNP. The predicted PK profile of the DNP-loaded microsphere in humans showed that the formulation with PLGA 7525A and the DPR of 1/9 could maintain drug concentration for a month and could control initial burst release. The data obtained from the study could be used as scientific evidence for decision-making in future formulation development.

The objective of this study was to explore the effect of geometry and tablet design on release pattern of tramadol hydrochloride as a model of freely soluble drug from matrix systems. Hydrophilic and hydrophobic matrices were prepared by direct compression method using HPMC with two different molecular weight and Kollidon® SR as a release-retarding agent respectively at drug: polymer ratio (1:5) for each excipient, in distinct strengths and geometries (i.e. shape, size and dimensions) at parallel and differing surface area to volume ratios. It was found that tramadol release from manufactured tablets is similar when the surface area to volume ratio is equal, regardless of the type of matrix former, drug strength, tablet design. Per contra, the tablet with smaller surface area to volume values had the slower release rate among the same shape. Thus, tablet geometry supplies additional versatility for these systems, making formulators to achieve the desired release characteristics for their drug of option.

Background: Ciprofloxacin (CIP) is a broad-spectrum antibiotic, used to treat various bacterial infections. Administration of conventional oral dosage forms of CIP is associated with multiple challenges such as short residence time of the drug in the gastrointestinal tract which could reduce bioavailability and effectiveness of the drug. This study aimed to design and develop novel floating microspheres for the sustained release of CIP in the stomach over 24 hours after oral administration, besides evaluating the effect of different variables on the characteristics of developed microspheres. Methods: Microspheres were developed by the solvent-evaporation method utilizing cellulose acetate and polyvinyl alcohol, then characterized for physicochemical properties including bulk density, buoyancy, and entrapment efficacy. The drug-excipient compatibility was evaluated by Fourier-transform infrared spectroscopy and the Scanning electron microscopy was used to observe the morphology of microspheres. The effects of the drug to polymer ratio, polymer concentration, and the pace of stirring through the preparation process, on the size and release rate were also evaluated. Results: Morphology analysis indicated round-shape microspheres with a mean particle size between 66-344 µm. The polydispersity index of prepared formulations was determined to be in the range of 0.129 to 0.230. It was observed that at higher polymer concentrations the drug release rate from microspheres decreased while the mean particle size increased. Increasing the drug to polymer ratio and decreasing the stirring speed increased the mean particle size. All formulations showed more than 70% cumulative drug release in the prolonged period of 24 h while remaining buoyant in the meantime. The formulations followed Higuchi and Korsmeyer-Peppas kinetics and release the drug by diffusion mechanism. Conclusions: Based on the results obtained from in vitro release study besides floating properties the prepared microspheres could be considered suitable for enhanced sustained-release of CIP following the oral administration.

Tenofovir disoproxil fumarate is a nucleotide reverse transcriptase inhibitor medication with a very bitter taste that plays an essential role in patient compliance in the oral dosing form. In this study, an attempt was made to mask the bitter taste of Tenofovir Disproxil Fumarate utilising a complexation process and an oral dispersible tablet formulation including super disintegrant croscarmellose sodium in various concentrations. Polymer Eudragit L -100 was used in the formulation of the complex with the Tenofovir Disproxil Fumarate. The complexes were formulated as 1:1, 1:2 and 1:3 ratios. The drug and polymer ratio were used to optimise the loading procedure. Taste masking was determined using the panel method, and the complexes were characterised using FTIR. Oral dispersible tablets were manufactured and assessed for pre-formulation and post-formulation parameters using the optimised drug-polymer complexes (1:3 ratio). The formulations were tested for thickness, hardness, diameter, weight variation, friability, disintegration time, invitro dissolution time, and stability. The test is passed by all parameters. This discovery can be used to develop a non-bitter Tenofovir Disoproxil Fumarate dosage form with high bioavailability and stability.

The effect of the SBR/BR blend ratio on marching modulus – no-plateau torque profile in vulcametry – of a silica filled tire tread compound is investigated. This is a tedious recurring problem, as it precludes the establishment of optimal vulcanization conditions. It was expected that the elastomer characteristics, SBR and BR in this study, and their physical affinity towards silica will influence the degree of silica dispersion and flocculation, thus the curing kinetics and marching modulus. Within this study, a wide series of properties related to dispersion and curing was measured depending on the polymer ratio, with the final goal to elaborate the contribution of the SBR/BR ratio to the marching modulus, as a means to suppress this phenomenon. The SBR/BR ratio indeed does influence the vulcanization characteristics of silica compounds; in particular the tendency to marching modulus. This effect stems from the specific characteristics of the polymers, mainly their interaction with silica and crosslinking reactivity. This was concluded based on the correlations found between the Marching Modulus Index (MMI) and the polymer ratio, as well as filler flocculation rate (FFR) and polymer-filler coupling rate (CR). A model explaining the different trends of MMI and FFR in the SBR-rich and BR-rich compounds is proposed.

Timolol maleate (TMM) is a hydrophilic model drug. The aim of this study was to formulate TMM-loaded microsponges to sustain TMM release and improve its corneal permeability compared with TMM-aqueous solution. The modified quasi-emulsion solvent diffusion technique (water/oil/oil) was used to prepare TMM-loaded microsponges. The impact of the polymer type (X1) and drug:polymer ratio (X2) were studied and optimized, using full factorial design. The production yield (PY) %, entrapment efficiency (EE) %, particles size (PS), and TMM released % after 6 h were selected as dependent variables. Depended on the desirability value by using the Design-Expert® software version 11, the optimized formulation was selected and subjected to further studies, such as scanning electron microscopy (SEM), porosity determination, powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), ex vivo permeation study, and corneal hydration level. The optimized formulation composed of TMM: EC within the proportion 1:9 exhibited PY of 96.55 ± 4.01%; EE of 72.00 ± 6.08%; PS (d90) of 6283.33 ± 145.71 nm and released 42.12 ± 3.93% of TMM after 6 h. Particles appeared porous with spherical shape. Thermal analysis proved that the drug has been homogeneously dispersed in its amorphous state. The optimized formulation showed higher corneal permeability about 1.45-fold higher than TMM-aqueous solution in a period of 6 h. The modified quasi-emulsion diffusion technique (water/oil/oil) is suitable for improving EE of hydrophilic drug (TMM) and the optimized TMM-loaded microsponge was succeeded to retard the release of TMM and improve its corneal permeability.

A graphene-based or carbon-based aerogel is a three-dimensional (3D) solid material in which the carbon atoms are arranged in a sheet-like nanostructure. In this study, we report the synthesis of low-density polymer-modified aerogel monoliths by 3D macro-assemblies of graphene oxide sheets that exhibit significant internal surface areas (982 m2/g) and high electrical conductivity (∼0.1 to 1 × 102 S/cm). Different types of materials were prepared to obtain a single monolithic solid starting from a suspension of single-layer graphene oxide (GO) sheets, and a polymer, made from the precursors 4-carboxybenzaldehyde and polyvinyl alcohol. These materials were used to cross-link the individual sheets by covalent bonds, resulting in wet-gels that were supercritically dried and then, in some cases, thermally reduced to yield graphene aerogel composites. The average densities were approaching 15-20 mg/cm3. This approach allowed for the modulation of distance between the sheets, pore dimension, surface area, and related properties. This specific GO/Polymer ratio has suitable malleability making it a viable candidate for use in conductivity 3D printing; it also has other properties suitable for energy storage, catalysis, sensing and biosensing applications, bioelectronics, and superconductors.

Background. Microsponges are intended to carry drugs with minimum dose, while delivering beneficial effects such as better drug stability and reduced adverse effects in recipients. The present investigation was aimed to develop and characterize microsponges containing tenofovir (TNF). Methods. Quasi-emulsion diffusion technique was used to prepare TNF-containing microsponges. Eudragit L-100 was used as a polymer, whereas glycerol and dibutylphthalates were used as plasticizers. Drug and polymer were experimented in five formulations (F1-F5) of different ratios such as 1:1, 1:2, 1:3, 1:4, and 1:5. They were characterized for various physical parameters such as size, crystallinity, and interactions. Results. Fourier-transform infrared spectroscopic results showed that there was no incompatibility between the drug and excipients. Drug entrapment efficacy was found between 47% and 67%, and the particle size ranges were between 4.52 μm and 8.98 μm. Cumulative drug diffusion of formulation F2 (drug:polymer ratio = 1:2) was found to be 84.15% in 180 min for an X-ray diffraction studies of pure drug and microsponges formulation clearly indicated the reduction in the crystallinity of the drug which could be the reason for the improved solubility of the drug. Scanning electron microscopy analysis results indicated that the formulations have excellent structure and almost all formulations exhibited in spherical shape. Conclusion. Based on all the evaluation parameters, formulation F2 was concluded as the best formulation, and it is an alternative approach for conventional therapy with better patient compliance.

The new investigation in this present work is to develop microsponges constructed novel drug delivery system for sustained action of Flurbiprofen. Quai-emulsion solvent diffusion method was engaged using Ethyl cellulose and Eudragit RS100 with drug: polymer ratio for development of microsponges. For optimization purposes, several factors are considered in the investigation. Several evaluation studies for the formed microsponges were carried out FT-IR, SEM, DSC, X-RD, particle size analysis, morphology, drug loading and In vitro drug release studies were carried out. Finally, it was concluded that there is no drug-polymer interaction as per DSC & FT-IR. Encapsulation efficiency, particle size and drug content showed a higher impact on alteration of drug-polymer ratio. SEM studies showed that morphological microsponges are spherical and porous in nature and with the mean particle size of 38.86 μm. The gel loaded with microsponges, were followed by In vitro and Ex vivo drug release studies by modified Franz diffusion cell. Skin delivery of optimized formulation enhanced the drug residence time and maintained therapeutic concentration for an extended period of time, which is possible to show sustained action of the drug.

Objective: The aim of this study is to prepare floating hollow microspheres encapsulating Sorafenib (SFN) to enhance its oral bioavailability. Methods: Gastro-floating hollow adhesive microspheres containing SFN were produced by using an emulsion solvent evaporation technique with ether and ethanol as solvents. Ethyl cellulose and carbopol 934P were used as the encapsulating carriers. The effects of formulation parameters like, solvent volume ratio, and drug to polymer ratio (D: P ratio), encapsulation efficiency percentage EE%, floating percentage, and release of SFN after 12 h (Rel12) were investigated and analyzed using a (32) full factorial design. Results: The floating percentage of the microspheres was found to be 76.5%. The in vitro drug release from these hollow microspheres followed the Higuchi model equation. The in vivo results showed that approximately 1.96-fold improvement in the relative bioavailability of the microspheres compared with that of the commercial tablet. Conclusion: The results demonstrate that the hollow microspheres with good gastro-floating ability are a promising delivery system to enhance SFN bioavailability.

In this study, we fabricated smart garments (SGs) based on nanoconductive fibers (NCFs) employing single-capillary electrospun stretchable styrene–butadiene–styrene nanofibers coated with silver nanoparticles. NCFs were dip-coated with pristine polytetrafluoroethylene (PTFE), intrinsically stretchable polymer pristine polyurethane (PU), and three different PTFE–PU blends to generate five different coated nanoconductive fibers (CNCFs). SGs for electricity generation and harvesting were fabricated by intertwining the NCFs and CNCFs. The SG based on pristine-PTFE-coated NCFs showed poor performance, owing to the rigidity of PTFE. Optimization of the PU polymer ratio and the power generation mechanism of the SGs was analyzed using various techniques. The SG with a PTFE:PU ratio of 8:2 generated the highest output current (9.86 nA) and was mechanically robust even under a high level of stretching (50%). Moreover, this SG was durable up to 175 stretching–relaxation cycles and could still deliver significant output current (2.88 nA). Strontium aluminate was dip-coated on the optimized SG to fabricate an incorporated smart garment (ISG) with improved light generation efficiency. The as-prepared ISG can be used in the future as a lightweight, reproducible, and renewable energy harvester.

Objectives The aim of this investigation was to develop an extended release formulation of diltiazem hydrochloride (DL) for once- and twice-daily administration, based on Eudragit (Eud) RL and RS microspheres using emulsion solvent evaporation. Materials and methods Formulations with different drug-polymer concentrations were produced and characterized in terms of yield, encapsulation efficiency (EE), particle size, and surface morphology. The drug release and thermal behavior of the microspheres were also investigated. Selected microspheres were then coated with Eud RS by continuous solvent evaporation, in order to modify the microspheres' properties and burst release. Results According to the results, the EE was in the range of 56%-93% for uncoated microspheres. The mean particle size of microspheres was different from 470 to above 1000 μm, based on various formulation variables. No difference was observed between the mean size of particles prepared with Eud RL and Eud RS. Microspheres showed sustained release behavior, which was affected by the drug:polymer ratio as well as particle size. Coating the microspheres not only improved the EE values (82%-92%) but also reduced the mean dissolution rate as well as the burst release. Conclusion Microspheres prepared with DL:Eud RL ratios of 1:3 and 1:4 showed release profiles in accordance with the USP criteria for a DL extended release product for dosing every 12 and 24 h, respectively.

Nanosponges (NS) of etodolac(ETO) was prepared using the emulsion solvent diffusion method ; the effects of drug: polymer ratio, the effect of level concentration of internal phase and stirring time and other variables that effect on the physical characteristics of NS were investigated and characterized, The selected formula was lyophilized then incorporated into hydrogel ; which also evaluated .The results show that the formulation that contain Drug: PVA:EC in ratio 1:3:2 is the best with smallest particle size 40.2±0.098 with polydispersibility0.005 and in vitro release 97.6±0.11%, , ETO NS Carbopol hydrogel produced a significant(p