Dinesh Dhamecha

Nepenthes khasiana mediated synthesis of stabilized gold nanoparticles: Characterization and biocompatibility studies

The current study summarizes a unique green process for the synthesis of gold nanoparticles by simple treatment of gold salts with aqueous extract of Nepenthes khasiana (NK)--a red listed medicinal plant and its characterization. Study on the effect of different process parameters like temperature, pH and stirring on surface and stability characteristics has been demonstrated. Formation of GNPs was visually observed by change in color from colorless to wine red and characterized by UV-Visible spectroscopy, FT-IR spectroscopy, Zetasizer, X-RD, ICP-AES, SEM-EDAX, AFM and TEM. In vitro stability studies of gold colloidal dispersion in various blood components suggest that, NK mediated GNPs exhibit remarkable in vitro stability in 2% bovine serum albumin, 2% human serum albumin (HSA), 0.2M histidine, and 0.2M cysteine but unstable in 5% NaCl solution and acidic pH. Biocompatibility of NK stabilized GNPs against normal mouse fibroblasts (L929) cell lines revealed nontoxic nature of GNPs and thus provides exceptional opportunities for their uses as nanomedicine for diagnosis and drug therapy. The role of antioxidant phytochemicals (flavonoids and polyphenols) of NK extract in synthesis of biocompatible and stabilized GNPs was demonstrated by estimating total flavonoid content, total phenolic content and total antioxidant capacity of extract before and after formation of GNPs. Fast and easy synthesis of biocompatible GNPs possesses unique physical and chemical features which serve as an advantage for its use in various biomedical applications. The overall approach designated in the present research investigation for the synthesis of GNPs is based on all 12 principles of green chemistry, in which no man-made chemical other than the gold chloride was used.

Green and ecofriendly synthesis of silver nanoparticles: Characterization, biocompatibility studies and gel formulation for treatment of infections in burns.

The current study summarizes a unique green process for the synthesis of silver nanoparticles (AgNPs) by simple treatment of silver nitrate with aqueous extract of Ammania baccifera. Phytosynthesized AgNPs were characterized by various advanced analytical methods and studied for its use against infections associated with burns. Formation of AgNPs was observed by visual color change from colorless to dark brown and confirmed by UV-visible characteristic peak at 436 nm. Zeta potential, particle size and polydispersity index of nano-silver were found to be -33.1 ± 1.12, 112.6 ± 6.8 nm and 0.3 ± 0.06 respectively. XRD spectra revealed crystalline nature of AgNPs whereas TEM confirmed the presence of mixed morphology of AgNPs. The overall approach designated in the present research investigation for the synthesis of AgNPs is based on all 12 principles of green chemistry, in which no man-made chemical other than the silver nitrate was used. Synthesized nano-silver colloidal dispersion was initially tested for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against a panel of organisms involved in infections associated with burns (Pseudomonas aeruginosa (PA), Staphylococcus aureus (SA) and methicillin resistant S. aureus (MRSA)). MIC and MBC were found to be in range of 0.992 to 7.93 and 7.93 to 31.75 μg/mL respectively. MBC was used for formulation of AgNP gel and tested for its efficacy using agar well diffusion method against PA, SA and MRSA. Comparative bactericidal efficacy of formulated gel (0.03% w/w) and marked formulation Silverex™ ionic (silver nitrate gel 0.2% w/w) showed equal zone of inhibition against all pathogenic bacteria. Formulated AgNP gel consisting of 95% lesser concentration of silver compared to marketed formulation was found to be equally effective against all organisms. Hence, the formulated AgNP gel could serve as a better alternative with least toxicity towards the treatment presently available for infections in burns.

Application of UV spectrophotometric method for easy and rapid estimation of lafutidine in bulk and pharmaceutical formulation.

Introduction: The present research work discusses the development of a UV estimation method for lafutidine. Simple, accurate, cost efficient, and reproducible spectrophotometric method has been developed for the estimation of Lafutidine in bulk and pharmaceutical dosage form. Materials and Methods: The Stock solution was prepared in a mixture of water and methanol (1:1). Further dilutions were made in water. Results: The drug was determined at maximum wavelength (λmax) 279 nm. Beers law was obeyed in the concentration range of 10–50 μg/ml having line equation y = 0.0100x + 0.035 with correlation coefficient of 0.999. Results of the analysis were validated statistically and by recovery study. Conclusion: The result of analysis was validated as per ICH guidelines and this method can be used for the routine analysis of lafutidine formulation.

Poloxamer 407-based intranasal thermoreversible gel of zolmitriptan-loaded nanoethosomes: formulation, optimization, evaluation and permeation studies

Abstract Zolmitriptan is the drug of choice for migraine, but low oral bioavailability (<50%) and recurrence of migraine lead to frequent dosing and increase in associated side effects. Increase in the residence time of drug at the site of drug absorption along with direct nose to brain targeting of zolmitriptan can be a solution to the existing problems. Hence, in the present investigation, thermoreversible intranasal gel of zolmitriptan-loaded nanoethosomes was formulated by using mucoadhesive polymers to increase the residence of the drug into the nasal cavity. The preparation of ethosomes was optimized by using 32 factorial design for percent drug entrapment efficiency, vesicle size, zeta potential, and polydispersity index. Optimized formulation E6 showed the vesicle size (171.67 nm) and entrapment efficiency (66%) when compared with the other formulations. Thermoreversible gels prepared by using poloxamer 407 showed the phase transition temperature at 32–33 °C which was in line with the nasal physiological temperature. The optimized ethosomes were loaded into the thermoreversible mucoadhesive gel optimized by varying concentrations of poloxamer 407, carbopol 934, HPMC K100, and evaluated for gel strength, gelation temperature, mucoadhesive strength, in vitro drug release, and ex vivo drug permeation, where G3 and G6 were found to be optimized formulations. In vitro drug release was studied by different kinetic models suggested that G3 (n = 0.582) and G6 (n = 0.648) showed Korsemeyer–Peppas (KKP) model indicating non-Fickian release profiles. A permeation coefficient of 5.92 and 5.9 µg/cm2 for G3 and G6, respectively, revealed very little difference in release rate after 24 h between both the formulations. Non-toxic nature of the gels on columnar epithelial cells was confirmed by histopathological evaluation.

Green Synthesis of Silver Nanoparticles Using Salacia chinensis: Characterization and its Antibacterial Activity

The aim of the present research work was to synthesize silver nanoparticles (AgNPs) using Salacia chinensis plant extract and to evaluate its antibacterial activity. AgNPs were successfully synthesized and formation of AgNPs was confirmed by visual color change and UV (ultraviolet) spectroscopy. Prepared AgNPs were purified and characterized by using dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM-EDAX), and transmission electron microscopy (TEM). UV peak at 434 nm confirmed the formation of AgNPs. DLS studies showed that AgNPs size prepared in all conditions were in the range of 100–200 nm. XRD studies revealed crystalline nature of AgNPs. EDAX studies confirmed the presence of silver in colloidal dispersion and images were recorded by using SEM and TEM. Synthesized AgNPs were found to be effective against Staphylococcus aureus and Pseudomonas aeruginosa. In conclusion, AgNPs could serve as a good alternative in treatment of bacterial infections in this era of multidrug resistance.

Simultaneous Estimation of Lafutidine and Domperidone by Ultraviolet Spectroscopy

A simple, accurate, and precise method for simultaneous estimation of Lafutidine and Domperidone in combined-dosage form have been described. The method employs formation and solving of simultaneous equations using 279 and 284 nm as two analytical wavelengths. This method allows the simultaneous determination of Lafutidine and Domperidone in concentration ranges employed for this purpose with the standard deviation of <1.0% in the assay of tablet.

Doxorubicin loaded gold nanoparticles: Implication of passive targeting on anticancer efficacy

The present work aims to investigate targeting potential of doxorubicin (Dox) functionalized gold nanoparticles (D-GNPs) for treatment of chemically induced fibrosarcoma in mice. Carrier GNPs were synthesised by green chemistry method and loaded with doxorubicin by incubation method. D-GNPs were studied for its biocompatibility using normal mouse fibroblasts (L929) and found to be cell compatible and non-toxic. D-GNPs (at a dose of 2.5, 2 and 1.5mg/kg equivalent to Dox) demonstrated passive targeting measured as function of antitumor efficacy against chemical induced fibrosarcoma which showed higher latency to the tumour growth as compared to free Dox (2.5mg/kg). D-GNPs exhibited significantly higher therapeutic anticancer efficacy (∼81% tumour suppression at dose of 2.5mg/kg equivalent to Dox) in the same model as compared to that of free doxorubicin (∼48% tumour suppression at dose of 2.5mg/kg). Safety profile and targeting efficiency of developed formulation was established by assessing cardiac and blood markers.

Green synthesis of gold nanoparticles using Pterocarpus marsupium: Characterization and biocompatibility studies

ABSTRACT The present study aims to synthesize gold nanoparticles (GNPs) by green method using Pterocarpus marsupium and to study the effect of various parameters like stirring, pH, and temperature on morphology and stability of GNPs. The study was further extended to evaluate the role of antioxidants in the green synthesis of GNPs. Formation of GNPs was confirmed by visual color change from colorless to wine red and UV-Visible spectrophotometry. Particle size was found to be in the range of 72–85 nm. There was no significant difference in the size and shape of GNPs prepared by different conditions; however, difference in zeta potential suggested difference in stability. GNPs prepared by heating (40°C) were comparatively more stable than GNPs synthesized at different conditions. Fourier-transform infrared spectroscopy suggests the presence of flavonoids and polyphenols. X-ray diffraction studies revealed the crystalline nature of GNPs, while transmission electron microscopy studies suggested mixed morphology of GNPs. In vitro stability studies revealed that GNPs were stable in all conditions except at lower pH and 5% NaCl solution. Synthesized GNPs were found biocompatible in nature. This ecofriendly method for the synthesis of GNPs is rapid and easy which yields stable and biocompatible GNPs which could be used for many biomedical applications.

Application of UV spectrophotometric method to study stress degradation behavior of cefprozil

Background: Cefprozil is a bactericidal drug that is used in the treatment of susceptible infections including upper and lower respiratory tract infections and skin and soft tissue infections. Materials and Methods: The objective of this research work was to develop and validate new, simple ultraviolet (UV) spectrophotometric method of Cefprozil in bulk and pharmaceutical dosage form and its application to study its stress degradation behavior. Results: The absorbance maxima peak was found at 280 nm, and linearity was observed in the concentration range of 2-10 μg/ml. The method was validated and found to be precise. Accuracy (percent recovery) for Cefprozil was found to be 99.117±1.005. Conclusion: A new method for estimation of Cefprozil by UV spectrophometry was developed and validated and Cefprozil was found to undergo degradation in all stress conditions.

Phytosynthesis of gold nanoparticles: Characterization, biocompatibility, and evaluation of its osteoinductive potential for application in implant dentistry

Gold nanoparticles have been extensively used in diagnostics, biomedical imaging, and drug delivery owing to simple method of synthesis and versatile surface functionalization. Present investigation aims to evaluate the osteoinductive property of Salacia chinensis (SC) mediated gold nanoparticles (GNPs) for its application in implant dentistry. The formation of GNPs was assessed initially using the visual method and characterized analytically by using UV-visible spectroscopy, Zetasizer, X-RD, ICP-AES, AFM, and TEM. Green synthesized GNPs exhibited a remarkable stability in various blood components (0.2 M histidine, 0.2 M cysteine 2% bovine serum albumin, and 2% human serum albumin) and were found to be nontoxic when evaluated for their cytocompatibility and blood compatibility using periodontal fibroblasts and erythrocytes respectively. Exposure of GNPs to MG-63 cell lines displayed increased percent cell viability (138 ± 27.4) compared to the control group (96 ± 3.7) which confirms its osteoinductive potential. Herein, it can be concluded that the stable, biocompatible and eco-friendly GNPs can be used as an effective bone inductive agent during dental implant therapy.