Development and evaluation of scaffold-based nanosponge formulation for controlled drug delivery of naproxen and ibuprofen

Purpose: To develop and evaluate nanosponge (NS) based sustained release formulations of naproxen (NAP) and ibuprofen (IBU).Method: Six formulations of each candidate drug were prepared by emulsion solvent diffusion method, using varying ratios of polymers, i.e., ethyl cellulose and polyvinyl alcohol. The prepared formulations were evaluated for various parameters including production yield, particle size, polydispersity index, actual drug content and entrapment efficiency. Morphological, structural and thermo-analytical evaluations were performed using various techniques. In vitro release studies were performed on selected formulations.Results: Nanosponge (NS) formulations of naproxen and ibuprofen were successfully prepared by emulsion solvent diffusion method. The particle size of naproxen and ibuprofen nanosponge formulations ranged from 347.6 to 1358 nm and 248.7 to 327.6 nm, respectively. Formulations with equal proportion of ethyl cellulose and drug resulted in nanosponges with the desired particle size. Production yield, actual drug content and entrapment efficiency was dependent on the ratio of ethyl cellulose and polyvinyl alcohol. Formulations with equal proportion showed least PDI values (0.09 for NAP and 0.07 for IBU) and highest zeta potential (-27.2 mV for NAP and -28.2 mV for IBU). Morphological, structural and thermo-analytical analysis confirmed the encapsulation of drugs in nanosponge cavities, and exhibited spherical and porous morphology. Nanosponge formulations gave a sustained release pattern, based on Higuchi model. Drug release mechanism was Fickian followed Korsmeyer-Peppas model, due probably to the porosity of the nanosponge.Conclusion: Sustained release nanosponge formulations of naproxen and ibuprofen have successfully been prepared.Keywords: Nanosponge, Naproxen, Ibuprofen, Emulsion solvent diffusion method, Sustained releas

Design and Utility of Metal/Metal Oxide Nanoparticles Mediated by Thioether End-Functionalized Polymeric Ligands

The past few decades have witnessed significant advances in the development of functionalized metal/metal oxide nanoparticles including those of inorganic noble metals and magnetic materials stabilized by various polymeric ligands. Recent applications of such functionalized nanoparticles, including those in bio-imaging, sensing, catalysis, drug delivery, and other biomedical applications have triggered the need for their facile and reproducible preparation with a better control over their size, shape, and surface chemistry. In this perspective, the multidentate polymer ligands containing functional groups like thiol, thioether, and ester are important surface ligands for designing and synthesizing stable nanoparticles (NPs) of metals or their oxides with reproducibility and high yield. These ligands have offered an unprecedented control over the particle size of both nanoparticles and nanoclusters with enhanced colloidal stability, having tunable solubility in aqueous and organic media, and tunable optical, magnetic, and fluorescent properties. This review summarizes the synthetic methodologies and stability of nanoparticles and fluorescent nanoclusters of metals (Au, Ag, Cu, Pt, and other transition metal oxides) prepared by using thioether based ligands and highlights their applications in bio-imaging, sensing, drug delivery, magnetic resonance imaging (MRI), and catalysis. The future applications of fluorescent metal NPs like thermal gradient optical imaging, single molecule optoelectronics, sensors, and optical components of the detector are also envisaged

Hydrophilic nanoparticles packed in oral tablets can improve the plasma profile of short half-life hydrophobic drugs

Water insoluble drugs with a short plasma half-life face the pharmacokinetic (PK) barriers of low oral absorption from the gastrointestinal route of drug administration and rapid clearance from systemic circulation. We report the synthesis and pharmaceutical profiling of a hybrid dosage form consisting of hydrophilic polymer encapsulated nanoparticles (NPs) of a hydrophobic drug, compressed inside tablets and optimized for efficient PK oral delivery. Four different polymers, i.e. hydroxypropylmethyl cellulose, Na-alginate, pectin and polyvinylpyrrolidone were used separately to nano-encapsulate (700 nm to 1 mm diameter) lornoxicam, a model hydrophobic drug with a short PK half-life, by a solvent emulsification method. The prepared NPs were compressed directly into tablets. The PK study in rats revealed improved oral bioavailability and better PK parameters of the drug after the oral administration of NPs carrying (NC) tablets for each polymer. The same was observed for the pharmacological activity in terms of carrageenan-induced inflammation in rat paw. In the in vitro drug release study, the NC tablets provided additional control over drug release by an interaction of the surface polymer of NPs with the tablet's matrix polymer. NPs showed better rheological properties as compared to crystalline drug, enabling efficient flow and processing of NPs in the tableting machine. The NC tablets appeared advantageous compared to conventional crystalline lornoxicam carrying (CL) tablets, conventional market tablets or even nanoparticles alone in terms of the ease of administration, improved drug stability, tunable drug release and enhanced oral bioavailability

Development and Mechanistic Studies of Ternary Nanocomposites for Hydrogen Production from Water Splitting to Yield Sustainable/Green Energy and Environmental Remediation

Photocatalysts lead vitally to water purifications and decarbonise environment each by wastewater treatment and hydrogen (H2) production as a renewable energy source from water-photolysis. This work deals with the photocatalytic degradation of ciprofloxacin (CIP) and H2 production by novel silver-nanoparticle (AgNPs) based ternary-nanocomposites of thiolated reduce-graphene oxide graphitic carbon nitride (AgNPs-S-rGO2%@g-C3N4) material. Herein, the optimised balanced ratio of thiolated reduce-graphene oxide in prepared ternary-nanocomposites played matchlessly to enhance activity by increasing the charge carriers’ movements via slowing down charge-recombination ratios. Reduced graphene oxide (rGO), >2 wt.% or <2 wt.%, rendered H2 production by light-shielding effect. As a result, CIP degradation was enhanced to 95.90% by AgNPs-S-rGO2%@g-C3N4 under the optimised pH(6) and catalyst dosage(25 mg/L) irradiating beneath visible-light (450 nm, 150 watts) for 70 min. The chemical and morphological analysis of AgNPs-S-rGO2%@g-C3N4 surface also supported the possible role of thiolation for this enhancement, assisted by surface plasmon resonance of AgNPs having size < 10 nm. Therefore, AgNPs-S-rGO2%@g-C3N4 has 3772.5 μmolg−1 h−1 H2 production, which is 6.43-fold higher than g-C3N4 having cyclic stability of 96% even after four consecutive cycles. The proposed mechanism for AgNPs-S-rGO2%@g-C3N4 revealed that the photo-excited electrons in the conduction-band of g-C3N4 react with the adhered water moieties to generate H2

Polysaccharide-Based Superporous, Superabsorbent, and Stimuli Responsive Hydrogel from Sweet Basil: A Novel Material for Sustained Drug Release

This study is carried out on polysaccharide-based hydrogel extracted from the seeds of Ocimum basilicum L. for its evaluation as a superabsorbent and stimuli responsive biomaterial for sustained release drug delivery system. O. basilicum (Syn: Basil) seed hydrogel (BSH) expressed high swelling capacity at pH 6.8 and 7.4 and deionized water. Highly reversible on-off switching (swelling-deswelling) behavior of BSH was ascertained in deionized water and ethanol, pH 7.4 and 1.2, and deionized water and normal saline. Scanning electron microscopy (SEM) of BSH has revealed macroporous structure of BSH having average pore size of 1.92 ± 3.83 μm noted after swelling and lyophilization. BSH containing tablet formulations showed a sustained release pattern of diclofenac sodium (DS) which is dependent on the concentration of BSH. When comparing with commercially available formulation of DS, even better sustained release behavior of DS was observed in BSH-based formulation. Super case-II transport mechanism is followed by the DS release from BSH matrix tablet. Haemocompatibility studies of BSH were also performed and found it nonhaemolytic and nonthrombogenic

Cationic silver nanoclusters as potent antimicrobials against multidrug-resistant bacteria

Bacterial multidrug resistance (MDR) is a serious healthcare issue caused by the long-term subtherapeutic clinical treatment of infectious diseases. Nanoscale engineering of metal nanoparticles has great potential to address this issue by tuning the nano-bio interface to target bacteria. Herein, we report the use of branched polyethylenimine-functionalized silver nanoclusters (bPEI-Ag NCs) to selectively kill MDR pathogenic bacteria by combining the antimicrobial activity of silver with the selective toxicity of bPEI toward bacteria. The minimum inhibitory concentration of bPEI-Ag NCs was determined against 12 uropathogenic MDR strains and found to be 10- to 15-fold lower than that of PEI and 2- to 3-fold lower than that of AgNO3 alone. Cell viability and hemolysis assays demonstrated the biocompatibility of bPEI-Ag NCs with human fibroblasts and red blood cells, with selective toxicity against MDR bacteria

Linear /nonlinear optical susceptibility spectroscopic constants of polyaniline@graphene oxide nanocomposite thin films

Graphene based conducting polymer composites are emerging contenders for newer optoelectronics devices like solar cells and linear / nonlinear optical devices. Beside these advanced applications, characterization approaches to analyze their liner/nonlinear optical constants, surface chemical state and structural analysis in thin film states are much needed. Herein, we reported a facile approach for the fabrication of graphene oxide (GO) and polyaniline (PANI) nano composites (PANI/GO) thin films using spin coating. Thereafter, the liner/nonlinear optical constants including first and third order nonlinear optical susceptibility were calculated using UV–vis (UV–vis) near infra-red absorption spectroscopic technique which will be an alternative to Z-scan approach and is poorly explored till now for such composites. Moreover, the increase or decrease in elemental bonding or interactions between C–C, C–O, C–O–C, C–N and percentage occurrence of C–OH, O–C[dbnd]O, –NH 2 , –N + H=, and –N + H 2 – functionalities in PANI/GO composites were concisely explored using X-ray photoelectron spectroscopy (XPS). Addition to proving the amorphous nature of PANI/GO composites in their X-ray diffraction studies, an increase in intensity of GO peak was explored due to an increase in elemental interactions among the GO and PANI. The reduction in band gap (3.27 to 2.66 eV) and diameter of Sp 2 carbon (19.62 to 15.96 nm) of PANI/GO thin films was observed with an increase in the GO concentration. The first order nonlinear optical susceptibility (X (1) ) is influenced by π-π* and n- π* interaction. The third order nonlinear optical susceptibility (X (3) ) was found in the range of 10 −10 to 10 -7 esu which can be further, optimized by changing the ratio of GO and PANI

Effect of tellurite on growth of extensively drug resistant (XDR) Mycobacterium tuberculosis and action on mycobacterial drug efflux pump

In the present study genotypic resistance of bacterial strain to first- and second-line anti-tuberculosis drugs was determined by Line probe assay. Toxic effect of tellurite on the growth of Mycobacterium tuberculosis (MTB) was determined by growing cells in different concentrations of tellurite (1 to 5 mM). Morphological effects of tellurite and uptake of metal in bacterial cells were confirmed by Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis. Change in fold expression of the efflux pump gene was measured by RT-PCR. Mycobacterial strain was characterized as XDR-TB based on the genotypic resistance to rifampicin and isoniazid, along with resistance to fluoroquinolones and second line injectable. XDR-TB showed black colonies in tellurite presence and growth was delayed (2–3 weeks) when compared with the control. The reduced cell size, metal accumulation and the characteristic tellurite peaks appeared in metal-treated cells. MTB showed MIC value of 1 mM and had high susceptibility for higher concentrations (2–5 mM). However, no significant metal inhibitory effect on the mmpL7 efflux system was determined. Tellurite shows significant growth reduction potential against XDR-TB strain. However, the exact mechanism of action needs to be elucidated with further research