Polyvinylpyrrolidone Research Articles

Physicochemical double protection enables stable MXene for high-rate performance hybrid supercapacitors

MXene, with metallic conductivity, strong hydrophilicity, and rich chemistries, has been widely used as electrode material for energy storage. However, the notorious issues of aggregation and oxidation for MXene significantly inhibit its electrochemical performance and further wide application. Herein, a physicochemical double protection strategy is proposed to stabilize MXene in the hydrothermal process effectively. Polyvinylpyrrolidone (PVP), with the structure of a long chain and abundant O/N function groups, provides physical protection against agglomeration (steric effect) and chemical protection against oxidation (electron transfer) at the same time, contributing to the synthesis of MXene-based hybrids with high conductivity and fully exposed active sites. As proof of the concept, 2D MXene/Co9S8 nanohybrids with a scaly surface are fabricated and present impressive performance, especially rate performance for hybrid supercapacitor (HSC) with MoS2 as the counter electrode. The HSC demonstrates a high energy density of 111 Wh kg−1 at 845 W kg−1 and an excellent rate performance of 61 Wh kg−1 at 16.9 kW kg−1.

Development of ropivacaine hydrochloride-loaded dissolving microneedles as a local anesthetic agent: A proof-of-concept

Ropivacaine hydrochloride (RPL) is a local anesthetic agent that has been widely used for the treatment of pain during or after surgery. However, this drug is only available in parenteral dosage form and may contribute to the infiltration of RPL into the plasma, causing some undesirable side effects. Intradermal delivery of RPL using dissolving microneedles may become a promising strategy to deliver such drugs into the skin. This research aimed to develop RPL-loaded dissolving microneedles (DMN-RPLs) as a proof of the concept of intradermal delivery of a local anesthetic. The DMN-RPLs were fabricated using either centrifugation or air-pressurized chamber methods. Several polymers, such as poly(vinyl pyrrolidone) (PVP), poly(vinyl alcohol) (PVA), and sodium hyaluronate (SH), were utilized for manufacturing the DMN-RPLs. The prepared DMN-RPLs were assessed for their thermal properties, chemical bonds, mechanical strength, insertion ability, skin-dissolution study, and drug content. Furthermore, in-skin deposition and dermatokinetic studies were also performed. The results showed that F9 (30 % w/w PVP-4 % w/w SH) and F10 (30 % w/w PVP-5 % w/w PVA) containing 5 % w/w of RPL were the most promising formulations, as shown by their needle height reduction (<10 %) and insertion depth (∼400 μm). Both formulations were also able to deliver more than 60 % of the RPL contained in the DMNs into the epidermis, dermis, and receiver compartment. This study, for the first time, has provided a proof concept to deliver RPL as a local anesthetic using DMNs and the intradermal route, aiming to minimize pain and discomfort during administration and improve the patient's experience.

Disulfide bonds as a molecular switch of enzyme-activatable anticancer drug precise release for fluorescence imaging and enhancing tumor therapy

Enzyme-activatable drug delivery systems have been developed for cancer diagnosis and therapy. However, targeted intracellular drug delivery is a challenge for precisely tumor imaging and therapy due to the increased stability of copolymer nanoparticles (NPs) is accompanied by a notable decrease in enzyme degradation. Herein, disulfide bond was designed as an enzyme-activatable molecular switch of SS-P(G2)2/DOX NPs. The copolymer NPs consists of polyvinylpyrrolidone (PVP) with disulfide bonds in the center and enzyme-degradable peptide dendrites (Phe-Lys) to form dendritic-linear-dendritic triblock copolymers (TBCs). The amphiphilic TBCs could be split into two identical amphiphilic diblock copolymers (DBCs) by glutathione (GSH) in cancer cells specifically while maintaining the same hydrophilic-lipophilic equilibrium. This structural transformation significantly reduced the stability of copolymer NPs and enhanced sensitivity of DOX release by cathepsin B-activated. Subsequently, the released DOX acted as an indicator of fluorescence imaging and chemotherapy drug for cancer cells. The polymeric NPs achieved excellent drug-loaded stability and prolonged blood circulation in vivo, and realized fluorescence imaging and specific cancer cell killing capabilities by responding to the overexpression of GSH and cathepsin B in tumor cells. Furthermore, the copolymer NPs demonstrated excellent blood compatibility and biosafety. Therefore, a novel strategy based on one tumor marker acting as the switch for another tumor microenvironment responsive drug delivery system could be designed for tumor intracellular imaging and chemotherapy.

Hydrogels in Biomedicine: Granular Controlled Release Systems Based on 2-Hydroxyethyl Methacrylate Copolymers. A Review

The article analyzes and summarizes the latest achievements in the field of polymer systems for controlled release devices based on hydrogel materials. Possible directions of drug delivery are presented, including the use of granular hydrogels, which work on the principle of drug sorption − release in the body. The research on the synthesis regularities, structure, properties, and prospects for the use of granular hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and its copolymers, in particular with polyvinylpyrrolidone (PVP), as systems for the controlled release of substances, in particular, drugs, is analyzed.

In Situ Fabrication of Electrospun Magnetic Film Under Laparoscopic Guidance for Preventing Postoperative Recurrence of Hepatocellular Carcinoma.

Despite laparoscopic-guided minimally invasive hepatectomy emerging as the primary approach for resecting hepatocellular carcinoma (HCC), there's still a significant gap in suitable biomaterials that seamlessly integrate with these techniques to achieve effective hemostasis and suppress residual tumors at the surgical margin. Electrospun films are increasingly used for wound closure, yet the employment of prefabricated electrospun films for hemostasis during minimally invasive HCC resection is hindered by prolonged operation times, complexity in implementation, limited visibility during surgery, and inadequate postoperative prevention of HCC recurrence. In this study, we integrated montmorillonite-iron oxide sheets into the PVP polymer framework, enhancing the resulting electrospun polyvinylpyrrolidone (PVP) /montmorillonite-iron oxide (MI) film (abbreviated as PMI) with robustness, hemostatic capability, and magnetocaloric properties. In contrast to the in vitro prefabricated electrospun films, the electrospun PMI film is designed to be formed in situ on liver wounds under laparoscopic guidance during hepatectomy. This design affords superior wound adaptability, facilitating meticulous wound closure and expeditious hemostasis, thereby simplifying the operative process and ultimately alleviating the workload of healthcare professionals. Moreover, when exposed to an alternating magnetic field, the film can efficiently ablate residual tumors, significantly augmenting the treatment efficacy of HCC. This article is protected by copyright. All rights reserved.

Rapid Fabrication of Tungsten Oxide-Based Electrochromic Devices through Femtosecond Laser Processing

The sol-gel method is a widely adopted technique for the preparation of tungsten trioxide (WO3) materials, favored for its cost-effectiveness and straightforward production procedures. However, this method encounters challenges such as prolonged annealing periods and limited flexibility in fabricating patterned WO3 films. This study introduces a novel approach that integrates femtosecond laser processing with the sol-gel method to enhance the fabrication of WO3 films. By adjusting polyvinylpyrrolidone (PVP) concentrations during sol-gel synthesis, precise control over film thickness and optimized film properties were achieved. The innovative technique significantly reduced the annealing time required to achieve an 80% transmittance rate from 90 min to 40 min, marking a 56% decrease. Laser processing increased the surface roughness of the films from Sa = 0.032 to Sa = 0.119, facilitating enhanced volatilization of organics during heat treatment. Additionally, this method improved the transmittance modulation of the films by 22% at 550 nm compared to unprocessed counterparts. This approach not only simplifies the manufacturing process but also enhances the optical efficiency of electrochromic devices, potentially leading to broader applications and more effective energy conservation strategies.

Construction of multi‐decay pathways and realizing polymer‐regulated organic smart luminescent materials

AbstractThe construction of multi‐decay pathways of smart organic light‐emitting materials has drawn intensive research enthusiasm owing to their substantial promise in diverse optoelectronic applications. Nowadays, numerous chemical substances have been refined to extend and enhance their intriguing luminescent properties. Nowadays, plenty of chemicals have been adapted to amplify more interesting luminescent properties. How to utilize an easy way to tune multi‐decay pathways resulting in various emissions is still challenging. Here, we present a triphenylamine derivative, TPA3BP, which exhibits a variety of multi‐decay pathways in different states and can exhibit thermally activated delayed fluorescence in both the polydimethylsiloxane and crystalline state, but also achieve room temperature phosphorescence by embedding it into the poly (methyl methacrylate) (PMMA) and polyvinyl pyrrolidone matrix. The multi‐decay luminescence can be attributed to the dual effect arising from the n‐π* transition of TPA3BP and the regulation of molecular transition pathways within the matrix environment. This intriguing phenomenon highlights the combined influence of TPA3BP's electronic transitions and the influence of the polarity and rigidity of the surrounding matrix on the observed characteristics. This advancement has widened the structural possibilities for multi‐decay luminescent materials, enabling their targeted synthesis for future applications, such as information encryption and smart anti‐counterfeiting.

Hybrid films loaded with 5-fluorouracil and Reglan for synergistic treatment of colon cancer via asynchronous dual-drug delivery

Combination therapy with oral administration of several active ingredients is a popular clinical treatment for cancer. However, the traditional method has poor convenience, less safety, and low efficiency for patients. The combination of traditional pharmaceutical techniques and advanced material conversion methods can provide new solutions to this issue. In this research, a new kind of hybrid film was created via coaxial electrospraying, followed by a casting process. The films were composed of Reglan and 5-fluorouracil (5-FU)-loaded cellulose acetate (CA) core-shell particles in a polyvinylpyrrolidone (PVP) film matrix. Microscopic observations of these films demonstrated a solid cross section loaded with core-shell particles. X-ray diffraction and Fourier-transform infrared tests verified that the Reglan and 5-FU loaded in the films showed amorphous states and fine compatibilities with the polymeric matrices, i.e., PVP and CA, respectively. In vitro dissolution tests indicated that the films were able to provide the desired asynchronous dual-drug delivery, fast release of Reglan, and sustained release of 5-FU. The controlled release mechanisms were shown to be an erosion mechanism for Reglan and a typical Fickian diffusion mechanism for 5-FU. The protocols reported herein pioneer a new approach for fabricating biomaterials loaded with multiple drugs, each with its own controlled release behavior, for synergistic cancer treatment.

UV-Irradiation Effects on the Optical Properties of Polyvinyl Alcohol/Carboxymethyl Cellulose/Polyvinyl Pyrrolidone/Tin Chromium Disulphide Nanocomposite Films for their Application in Optoelectronic Devices

A nanocomposite (NC) film containing polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and polyvinyl pyrrolidone (PVP) polymers and tin chromium disulfide (Sn0.75Cr0.25S2) nanoparticles (NPs) was prepared using thermolysis and casting techniques. The prepared NPs were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. The induced alterations in the optical and color properties of the prepared PVA/CMC/PVP/Sn0.75Cr0.25S2 NC film due to UV irradiation, within fluences ranging from 10 to 80 Joule/cm2 (J/cm2), were characterized via UV spectroscopy and the International Commission on Illumination (CIE) color changes techniques. As the UV fluence increased up to 80 J/cm2, the maximum fluence used, both the direct and indirect bandgaps decreased. We attribute this to the dominance of formed chain crosslinks that destroyed the ordered structure and, thus, increased the amorphous regions. The effect of UV irradiation on the absorbance, refractive index, real and imaginary dielectric parameters and optical conductivity of the NC samples were studied. Furthermore, the optical color changes between the pristine and the irradiated films were evaluated. The pristine NC film was uncolored. It showed significant color changes when irradiated with the UV radiation at increasing fluences up to 80 J/cm2. The changes in the optical properties of PVA/CMC/PVP/Sn0.75Cr0.25S2 NC film suggested its usage as a promising candidate for future optoelectronics characterization techniques.

Therapeutic and Photodegradation Applications of PVA, PVP and PEG Capped NixCo1-xFe2O4 Nanoparticles by a Hydrothermal Method

Magnetic Ferrite nanoparticles (MFNPs), are promising for diverse application owing to their divergent functional properties. Among the MFNPs cobalt ferrite nanocomposites have gained a lot of attention for myriad biomedical application. This paper describes our synthesis of nickel doped cobalt ferrite capped in polyethylene glycol (PEG), polyvinyl alcohol (PVA) and polyvinyl pyrolidone (PVP) by a hydrothermal method. Several characterizations techniques, such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating sample magnetometry (VSM) were used to determine the physico-chemical properties of the formulated MFNPs. The physico-chemical properties of the MFNPs were influenced by the PEG, PVA and PVP. The formulated nanoparticles showed enhanced antidiabetic, antioxidant and antimicrobial activities. The PVP capped MFNPs, had the highest antifungi and antidiabetic activities, while the PVA capped MFNPs showed the highest antibacterial and antioxidant activities. Hence, the introduction of these polymers in the samples heightened their biomedical performance. The photodegradation of crystal violet by the MFNPs was also enhanced with the PVP mediated sample having the highest efficiency.

Engineered beads-on-a-string nanocomposites for an improved drug fast-sustained bi-stage release

Nanocomposites represent one of the most useful strategies for resolving the pharmaceutical challenge about the dissolution and delivery of poorly water-soluble drugs. Besides the compatibility between the drug and polymeric carriers, the physical shapes of materials also play their important roles on the release behaviors of a guest poorly water-soluble drug from the host polymeric matrices. In this study, three kinds of nanocomposites in the forms of homogeneous nanofibers (E1), spindles-on-a-string (E2), and beads-on-a-string (E3) were prepared using electrospinning with ketoprofen (KET) as the model drug and a mixture of ethylcellulose (EC) and polyvinylpyrrolidone (PVP) as the polymeric matrices. Controllable preparation mechanisms of these morphologies are disclosed based on the results of SEM, TEM, and processes observations. XRD and FTIR data demonstrated that KET was compatible with PVP and EC. In vitro dissolution tests verified that all the three nanocomposites were able to provide the typical bi-stage fast-sustained release profiles of KET. Whereas, the beads-on-a-string E3 had a better functional performance than the spindles-on-a-string E2, and the homogeneous nanofibers E1 in terms of the KET sustained release profiles in the second stage. The protocols reported here pioneered a new way for developing novel functional nanocomposites based on the process-shape-performance relationship.

Study on the Interaction of Interfacial Tension Between Water and Oil Surfaces In The Presence of Aluminium Coated With Polyvinylpyrrolidone (PVP) Nanoparticles

Applications of nanotechnology are frequently used in the oil and gas sector. However, nanoparticles boost sand consolidation, lower interfacial tension between water and oil, and improve the mobility of trapped oil to increase crude oil recovery in enhanced petroleum recovery (EOR). Using aluminium PVP-coated low-porosity sand packing, the effects of nanoparticles on interfacial tension and water-oil surface contact were examined in this study. The horizontal column was filled with low-porosity sand, and the nanopowders were suspended in deionized water. The four distinct nanoparticle suspension pore volumes (PV) used in this experiment are 0.25, 0.5, 0.75, and 1.0 PV. At the column's output, the sample is then deposited, and the effluent is analysed and contrasted using IFT and viscosity with a solid viscometer. In this investigation, it was discovered that the water target zone had a very limited pore volume and only received 0.52 PV of injected nanoparticles. The better the oil can be extracted, the lower the viscosity and IFT value. The removal of the oil droplet and increased oil output for EOR could result from the transport of PVP nanoparticles coated with aluminium.

Fabrication and evaluation of centrifugal spun Miconazole-loaded sugar-based fibers

Oral candidiasis is considered a very common infection in the oral cavity caused by Candida albicans (C. albicans). Miconazole is considered to be a very effective drug against many fungal infections but suffers from water insolubility and an unpleasant taste. Therefore, this study aims to prepare miconazole encapsulated into a sugar-based fibrous system composed of sucrose as the main component, along with polyvinylpyrrolidone (PVP) as a stabilizer, and miconazole using centrifugal spinning and to assess its antifungal activity in in vitro and in vivo mice models. The data showed that the miconazole-loaded fibers had a diameter of 6.6 ± 2.5 μm, an encapsulation efficiency % of 52 ± 4.5 %, a drug loading of 52 ± 4.5 μg/mg and full and rapid drug release after 4 h. The in vitro antifungal assessment exhibited that the miconazole-loaded fibers have a comparable antifungal activity to that of the positive control miconazole against two C. albicans strains. The in vivo mice oral candidiasis model demonstrated the ability of the miconazole-loaded fibers to inhibit C. albicans similarly to the commercially available product after 7 days of the treatment. Therefore, the miconazole-loaded fibers can be used as a potential alternative medication for oral candidiasis owing to its anti-Candida activity and its presence as a cotton-candy-like dosage form that would improve the children's acceptability and adherence. Further in vivo testing and long-term stability are required to ensure the safety, efficacy, and stability of this dosage form before its clinical application.

Plasmonic AgNPs reinforced flexible hydrogel Surface-Enhanced Raman scattering (SERS) sensor for in-situ detection of curved samples

In-situ detection of analytes on curved surfaces is a persistent and great challenge in the application of SERS technique. A hydrogel-based flexible SERS substrate demonstrates a unique charm for providing close contact to the real-sample surface but limited by its weak enhancement capability in the quantitative analysis. Herein, we report a reinforced hydrogel by reduction of plasmonic silver nanoparticles (AgNPs) on a PNIPAM membrane with the aid of polyvinylpyrrolidone (PVP) surfactant. The modification of AgNPs on PNIPAM endows the AgNPs/PNIPAM composite hydrogel with good mechanical properties and reinforced swelling property. Moreover, the AgNPs/PNIPAM hydrogel-based SERS sensor exhibits an enhanced SERS sensitivity as well as improved signal uniformity (RSD ＜10 %), and the detection concentration for pesticide molecules can be down to 10-9 M. Due to the fingerprint feature of SERS, multicomponent detection of pesticide mixtures was readily realized. In addition, the flexible AgNPs/PNIPAM hydrogel was successfully applied to the curved apple surface for SERS detection. Notably, it is capable of achieving qualitative and quantitative analyses of different pesticides, which has lower analytical concentrations than European Union (EU) standards, indicating the potential applications in rapid in-situ pesticide analysis.

QbD Assisted Systematic Review for Optimizing the Selection of PVP as a Ternary Substance in Enhancing the Complexation Efficiency of Cyclodextrins: a Pilot Study.

Inclusion complexes require higher concentration of Beta cyclodextrins (βCD) resulting in increased formulation bulk, toxicity, and production costs. This systematic review offers a comprehensive analysis using Quality by design (QbD) as a tool to predict potential applications of Polyvinylpyrrolidone (PVP) as a ternary substance to address issues of inclusion complexes. We reviewed 623 documents from 2013 to 2023 and Eighteen (18) research papers were selected for statistical and meta-analysis using the QbD concept to identify the most critical factors for selecting drugs and effect of PVP on inclusion complexes. The QbD analysis revealed that Molecular weight (MW), Partition coefficient (Log P), and the auxiliary substance ratio directly affected complexation efficiency (CE), thermodynamic stability in terms of Gibbs free energy (ΔG), and percent drug release. However, Stability constant (Ks) remained unaffected by any of these parameters. The results showed that low MW (250), median Log P (6), and a βCD: PVP ratio of 2:3 would result in higher CE, lower G, and improved drug release. PVP improves drug solubility, enhances delivery and therapeutic outcomes, and counteracts increased drug ionization due to decreased pH. In certain cases, its bulky nature and hydrogen bonding with CD molecules can form non-inclusion complexes. The findings of the study shows that there is potential molecular interaction between PVP and β-cyclodextrins, which possibly enhances the stability of inclusion complexes for drug with low MW and log P values less than 9. The systematic review shows a comprehensive methodology based on QbD offers a replicable template for future investigations into drug formulation research.

Synthesis, Characterization, and Stability Optimization of Ibuprofen Cocrystals eEploying Various Hydrophilic Polymers.

Cocrystals are an efficient way for the delivery of low soluble drugs but when dissolved they rapidly disproportionate. To formulate the cocrystals in tablets, cocrystals must be stabilized. In this study ibuprofen-nicotinamide (IBU-NIC) cocrystals were synthesized initially by slow solvent evaporation and for bulk production by fast solvent evaporation techniques. The cocrystals were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectrophotometer (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and optical microscopy. The ibuprofen cocrystals showed greater solubility compared to the parent drug. Intrinsic dissolution data was utilized for efficacious screening of tablet formulations. Using hydrophilic polymers at a ratio of 6:1 (polymer to IBU-NIC cocrystal ratio), hydroxypropyl methylcellulose (F1), polyvinylpyrrolidone (PVP) K-30 (F2) and PVP K-90 (F3), three tablet formulations were prepared that stabilized cocrystals during dissolution. The drug release profiles after 60 minutes from formulations F1 (92.30), F2 (98.54), F3 (99.88) were all higher compared to the marketed brand BRUFEN® F, (79.61%) in a simulated intestinal media (p<0.001). Significant increase in the dissolution rate of cocrystal was observed with no phase change in all formulations.

Processing browning and increasing multiplication and rotting of Peach rootstock cv. Garnem by using antioxidants and plant growth regulators in vitro

The study aimed to find an accurate propagation program for the rootstock of peach Prunus persica cv. Garnem. The apical shoots and nodes of this rootstock were used as explants for the stages of initiation and multiplication, and they were planted on MS medium after adding different concentrations of Active Charcoal (AC), Polyvinyl Pyrrolidone (PVP), and Benzyl adenine (BA). The shoots were planted for the purpose of rooting on MS medium containing different concentrations of salts (1/4 MS, 1/2 MS and full MS salts) with different concentrations of IBA. In the establishment phase, the apical shoots grown on medium supplied with AC were given the highest response rate, the highest average length of plantlet, and the highest number of leaves. The best multiplication of explants in terms of the number of shoots and their length were obtained when cultivated on a medium supplemented with BA at 1 and 2 mg.L-1, whereas the application of BA at 1 mg. L-1 to the cultivated nodes gave the highest number of leaves. The best rooting percent was obtained when plantlets were s treated with 2 mg. L-1 was applied to 1/4 MS medium. The highest number of roots was obtained from plantlets grown in 1/2 MS medium treated with IBA at 3 mg.L-1, whereas the longest root was obtained from plantlets grown in 1/2 MS medium treated with 1 mg.L-1IBA.

Development of dissolving microneedles loaded with fucoidan for enhanced anti-aging activity: An in vivo study in mice animal model

Skin aging occurs naturally as essential skin components gradually decline, leading to issues such as fine lines, wrinkles, and pigmentation. Fucoidan, a natural bioactive compound, holds potential for addressing these age-related concerns. However, its hydrophilic nature and substantial molecular weight hinder its absorption into the skin. In this study, we utilized polyvinyl pyrrolidone K30 (PVP) and polyvinyl alcohol (PVA) as polymers to fabricate dissolving microneedles loaded with fucoidan (DMN-F). The DMN-F formulations were examined for physical characteristics, stability, permeability, toxicity, and efficacy in animal models. These formulations exhibited consistent polymer blends with a conical structure and uniform cone-shaped design. Microneedle structure and penetration capability gradually decreased with increasing fucoidan concentration, with storage recommended at approximately 33 % relative humidity (RH). Ex vivo studies showed that DMN-F efficiently delivered up to 95.03 ± 2.36 % of the total fucoidan concentration into the skin. In vivo investigations revealed that DMN-F effectively reduced wrinkles, improved skin elasticity, maintained moisture levels, and increased epidermal thickness. Histological images provided additional evidence of DMN-F’s positive effects on these aging parameters. The results confirm that the DMN-F formulation effectively delivers fucoidan into the skin, allowing it to treat and mitigate signs of aging.

One-Pot Synthesis of Pd Nanoparticles Supported on Carbide-Derived Carbon for Oxygen Reduction Reaction.

We explored two methods for synthesizing Pd nanoparticles using three different carbide-derived carbon (CDC) support materials, one of which was nitrogen-doped. These materials were studied for oxygen reduction reaction (ORR) in 0.1 M KOH solution, and the resulting CDC/Pd catalysts were characterized using TEM, XRD, and XPS. The citrate method and the polyol method using polyvinylpyrrolidone (PVP) as a capping agent were employed to elucidate the impact of the support material on the final catalyst. The N-doping of the CDC material resulted in smaller Pd nanoparticles, but only in the case of the citrate method. This suggests that the influence of support is weaker when using the polyol method. The citrate method with CDC1, which is predominantly microporous, led to a higher degree of agglomeration and formation of larger particles in comparison to supports, which possessed a higher degree of mesoporosity. We achieved smaller Pd particle sizes using citrate and NaBH4 compared to the ethylene glycol PVP method. Pd deposited on CDC2 and CDC3 supports showed similar specific activity (SA), suggesting that the N-doping did not significantly influence the ORR process. The highest SA value was observed for CDC1/Pd_Cit, which could be attributed to the formation of larger Pd particles and agglomerates.

Development and Characterisation of Valsartan Immediate Release Dosage Form Using Solubility Enhancement Technique

Abstract Objective The objective of the present investigation is to improve the solubility of valsartan and prepare immediate release tablets. Materials and methods To increase the solubility and bioavailability of valsartan, a low-soluble antihypertensive drug, immediate release dosage forms were formulated by a direct compression method using a solid dispersion technique with three different carriers (β-cyclodextrin, polyvinyl pyrrolidone K30 and poloxamer 188) at three different ratios (1:3, 1:4 and 1:5). Nine physical mixtures (PM1–PM9) were prepared and various physical parameters were characterised in in vitro release studies. Results Out of the prepared physical mixtures, PM8 showed the best results, with 94.2% of the drug dissolving within 30 min. Formulation PM8 solid dispersion further used for the preparation of valsartan immediate release tablets by using sodium starch glycolate superdisintegrant, at different concentrations (3%, 4% and 5%; i.e., IF1, IF2 and IF3 formulations, respectively). The optimised formulation showed friability and disintegration values of 0.456±0.9 and 6.2±0.4 min. Among the three immediate release formulations, IF2, which contains 4% sodium starch glycolate, demonstrated an 84.46% drug release in 30 min and a 99.69% drug release in 1 hr, indicating increased drug solubility. When compared with a valsartan pure drug, the solubility of the solid dispersion increased by 135.06-fold. Discussion and conclusion The results show that the optimised IF2 formulation demonstrated enhanced drug solubility by 135.06-fold, using a solid dispersion technique with poloxamer 188. This can be explained by the conversion of crystalline to an amorphous form of drug, leading to a reduction in the contact angle between the drug and the gastric medium. It can be concluded that poloxamer 188 is a suitable carrier and that use of a physical mixture technique is an applicable method to improve the solubility of valsartan.