BackgroundThe study on newer antimicrobial agent from metal based nano materials has augmented in recent years for the management of multidrug resistance microorganisms. In our present investigation, we synthesized silver nanoparticles (AgNP’s) from red algae, Gracilaria crassa as beginning material which effectively condensed the silver ions to silver nanoparticles with less price tag and no risk.MethodsSilver nanoparticles were prepared by simple reaction of 1 mM AgNO3 with G. crassa extracts at room temperature. The fabricated AgNP’s were subjected for characterization and screened against various microorganisms for antibacterial activity.ResultsUV–Vis spectroscopy (200–800 nm), XRD, FESEM and EDAX, were performed for AgNP’s. UV–Vis spectroscopy demonstrated the absorption edge at 443 nm and EDAX pattern is purely due to the particle size and face centered cubic (fcc) symmetry of nanoparticles. Average size lays at 122.7 nm and zeta potential was found to be −34.9 mV. The antibacterial outcome of synthesized AgNP’s (at the dose of 20 and 40 µg/ml) was evaluated against Escherichia coli, Proteus mirabilis, Bacillus subtilis and Pseudomonas aeruginosa. The mechanism of synthesized AgNP’s bactericidal bustle is discussed in terms of interaction with the cell membrane of bacteria. The activity was found to be sky-scraping in a dose dependent manner.ConclusionThus, environmental friendly, cost effective, non hazardous stable nanoparticles were prepared by green synthesis using red algae, G. crassa. Synthesized G. crassa AgNP’s were in acceptable size and shape. Further, it elicits better bactericidal activity against microorganism. This will assure the out put of superior antibacterial formulation for near future.Graphical Abstract

The objective of the present research is to prepare stable nano suspensions of Valsartan (VAL) with high solubility and dissolution. VAL is an orally administered anti-hypertensive drug with lower bio-availability of 25%, this is attributed to its lower aqueous solubility (0.082 mg/ml). VAL nano suspensions were prepared by using a bottom-up precipitation technique using five level full factorial central composite design (CCD). The optimized nano formulations NS21, NS22, NS23 showed the particle size of 268.42±8.99, 288.3±11.32, 293.46±6.92 nm, zeta potential of 20.89±0.79, 26.01 ±1.02, 21.34±0.43 mVs and the dissolution efficiency of 93.10±1.459, 91.84±1.419, 89.47±0.644 % respectively. SEM & AFM studies represent the formation of fine irregularly shaped particles with smooth surfaces on nanosization. X-rd studies confirmed the physical state conversion of crystalline drug into amorphous form. Drug excipient compatibility was studied using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The investigation pragmatic the solubility and dissolution efficiency of VAL in nanosuspension was significantly higher when compared with its pure form. Finally, it is concluded that, nanosuspension approach could be an ideal, promising approach to increase the solubility and dissolution of BCS-II drugs like Valsartan.

In our present investigation, synthesis of nontoxic, eco friendly and cost effective silver nanoparticles, Phyllanthus acidus (P. acidus) was used as starting material. The influence of phyto-constituents present in aqueous extracts of Phyllanthus acidus was found to be effective in reduction of silver nitrate to free silver nanoparticles (PA-AgNPs). HPTLC finger print analysis reveals the presence of flavonoid, quercetin in aqueous extracts of Phyllanthus acidus. Surface plasmon racemonance exhibited λ max at 462 nm through UV–Vis spectroscopy. Zeta size revealed that the size of nanoparticles were with in the range of 65–250 nm with polydisperse index (PDI) of 0.451. The negative charge of zeta potential value (− 16.4) indicates repulsion among PA-AgNPs with their excellent stability. FESEM-EDAX, XRD and TEM analysis confirmed the presence of nano-crystalline PA-AgNPs with different morphological textures. Further, PA-AgNPs has shown potent antibacterial effect on E. coli cells. The greater antibacterial effect (viable and dead cells) of PA-AgNPs were confirmed by using acridine orange (AO) dye which can able to provide insight of healthy as well as damaged DNA. Live cells emit florescence green and dead cells (treated with PA-AgNPS at 20 and 40 µg/ml) appear as pale orange red colour. Post treatment, investigations of PA-AgNPs on E. coli cells under SEM was found to be effective against cell membrane damages which leads to cell death or cell growth arrest. Hence, from the above findings, we strongly recommend silver nanoparticles from Phyllanthus acidus can be used as a potential source for antimicrobial agent for chronic infections and also against other harmful microorganisms.

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Syzygium cumini (L.) commonly known as jamun belongs to the Myrtaceae family. The aim of the present study includes phytochemical investigation and in vitro anti-oxidant capacity of various crude extracts from the bark of syzygium cumini (L.) by various anti-oxidant assays namely DPPH (2, 2-diphenyl-1-picrylhydrazyl), Nitric Oxide (NO) and Hydrogen peroxide (H 2 O 2 ). Chloroform Ethyl acetate (EA) and Methanolic (MeOH) extracts of S. cumini gave positive results for steroids, alkaloids, tannins and flavonoids. The scavenging ability of chloroform, ethyl acetate and methanolic extracts along with standard Ascorbic acid were evaluated between the range of 20µg/ml to 300µg/ml using DPPH anti-oxidant assay and the IC 50 values were found to 41µg/mL, 57 µg/mL, 53 µg/mL and 6.1 µg/mL respectively. To prove further its anti-oxidant activity, they were evaluated using NO and H 2 O 2 antioxidant assays.