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Dhakar RC
Journal of Drug Delivery and Therapeutics , 2011,
Abstract: Transmucosal nasal delivery is a promising drug delivery option where common drug administrations (e.g., intravenous, intramuscular, or oral) are inapplicable. Recently, it has been shown that many drugs have better bioavailability by nasal route than by oral route. This has been attributed to rich vasculature and a highly permeable structure of the nasal mucosa coupled with avoidance of hepatic first-pass elimination, gut wall metabolism and/or destruction in the gastrointestinal tract. The physiology of the nose presents obstacles, but offers a promising route for non-invasive systemic delivery of numerous therapies and debatably drug delivery route to the brain. Intranasal microemulsions, gels and microspheres have gained increased interest in recent years as a delivery system for protein and peptides through nasal route. Since building a more efficient nasal drug delivery device requires not only better device design but a far more versatile technology platform; one that delivers optimal nasal deposition, with formulation flexibility to work successfully with the many variables of the formulation itself. Thus present review focuses on innovations in nasal drug delivery devices
Garg SK,Danodia A,Dangi V,Dhakar RC
Journal of Drug Delivery and Therapeutics , 2011,
Abstract: The route of administration is critical for any medicine. For decades, the most common dosage forms were either oral or injection. Patients generally preferred oral therapies over injected medications because oral delivery is non-invasive and convenient. Drug delivery by buccal route presents unique advantages that are not available with other modes of administration. Buccal drug delivery is a promising option where common drug administrations (e.g., intravenous, intramuscular) are inapplicable. Recently, it has been shown that many drugs have better bioavailability by buccal route than by oral route. This has been attributed to rich vasculature and a highly permeable structure of the buccal mucosa coupled with avoidance of hepatic first-pass elimination, gut wall metabolism and/or destruction in the gastrointestinal tract. The physiology of the buccal mucosa offers a promising route for non-invasive systemic delivery of biotherapeutics. The present article highlights the advantages, physicochemical factors and formulation related parameters affecting the buccal drug delivery. It also includes a note on polymer used in buccal drug delivery and buccal drug absorption pathways.
Ram Chand Dhakar
International Journal of Pharmaceutical Research and Development , 2010,
Abstract: The work was aim to formulate and evaluate mucoadhesive microspheres of Rosiglitazone Maleate for treatment of diabetes type-2 by combine the potential advantages of mucoadhesion with controlled drug delivery using various ratio of polymers. Mucoadhesive microspheres were prepared by emulsification solvent evaporation techniques. Microspheres were found discrete, spherical and free flowing. They ranged in particle size from 21-37 μm. The microspheres exhibits good mucoadhesive property in in-vitro wash off test and showed high drug entrapment efficiency. Rosiglitazone Maleate release from these microspheres was slowed, extended and depended on the type of polymer used. The formulation F1 and F2 showed consistent drug release for up to 12 h time period. Among all the formulations, F1 containing sodium carboxy methyl cellulose and F2 containing Carbopol 934 showed the reproducible results with best mucoadhesive profile and good surface morphology. The work has demonstrated that among all the formulations of microspheres, particularly those of formulation F1 are promising candidates for the sustained release of Rosiglitazone Maleate in the gastrointestinal tract.
Laccase Production from a Temperature and pH Tolerant Fungal Strain of Trametes hirsuta (MTCC 11397)
Kusum Dhakar,Anita Pandey
Enzyme Research , 2013, DOI: 10.1155/2013/869062
Abstract: Laccase production by a temperature and pH tolerant fungal strain (GBPI-CDF-03) isolated from a glacial site in Indian Himalayan Region (IHR) has been investigated. The fungus developed white cottony mass on potato dextrose agar and revealed thread-like mycelium under microscope. ITS region analysis of fungus showed its 100% similarity with Trametes hirsuta. The fungus tolerated temperature from 4 to 48°C?±?2 (25°C opt.) and pH 3–13 (5–7 opt.). Molecular weight of laccase was determined approximately 45?kDa by native PAGE. Amplification of laccase gene fragment (corresponding to the copper-binding conserved domain) contained 200?bp. The optimum pH for laccase production, at optimum growth temperature, was determined between 5.5 and 7.5. In optimization experiments, fructose and ammonium sulfate were found to be the best carbon and nitrogen sources, respectively, for enhancing the laccase production. Production of laccase was favored by high carbon/nitrogen ratio. Addition of CuSO4 (up to 1.0?mM) induced laccase production up to 2-fold, in case of 0.4?mM concentration. Addition of organic solvents also induced the production of laccase; acetone showed the highest (2-fold) induction. The study has implications in bioprospecting of ecologically resilient microbial strains. 1. Introduction Laccases (phenol oxidases; E.C., also known as multicopper blue oxidases, belong to the oxidoreductase group of enzymes. Biochemically, they are glycoproteins carrying molecular mass between 50?kDa and 130?kDa [1]. Fungi, belonging to ascomycetes, deuteromycetes, and basidiomycetes, are known to produce laccases of ecological as well as biotechnological importance, such as biodegradation and bioremediation [1–4]. In addition, laccases are also responsible for various physiological functions in fungi [5]. Due to their broad specificity toward substrate, they can oxidize a range of chemical compounds leading to various industrial applications [6]. Enhancement of laccase production, by modifying the nutritional and physiological conditions during cultivation of promising fungi, is a prerequisite for their optimum utilization at industrial scale. Besides nutritional supplements, inducers like organic solvents and metal ions also play important role in production of laccases [3, 7, 8]. Isolation of new microbial strains of biotechnological applications from various ecological habitats is a prerequisite for industrial growth. The fungi capable of producing laccase at wider temperature and pH range are likely to play important role in biodegradation under low
Comparative evaluation of free radical scavenging activity of Boerhaavia diffusa root extracts (BDRE) and determination of dose effectivity against radiation induced damages in Swiss albino mice
P Dhakar,M R Saini,J Sharma
International Journal of Applied Research in Natural Products , 2012,
Abstract: Summary: Purpose of the study was to evaluate free radical scavenging activity (FRSA) of root extracts of Boerhaavia diffusa in different solvents and to examine its dose effectivity against radiation induced damages in Swiss albino mice. Scavenging activities of aqueous, ethanolic and hydroethanolic extracts of B. diffusa roots were evaluated by DPPH (2, 2-diphenyl-1 picryl hydrazyl), ABTS (2,2’-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid) and NO (nitric oxide) assay to find the most effective extract and results were expressed as IC50. To find the most effective dose, hydroethanolic root extract (50:50) of B. diffusa was orally administered to Swiss albino mice at the dose of 250, 500 and 1000 mg/Kg.body.weight for 15 consecutive days prior to irradiation with 8 Gy gamma radiation. Results indicates that hydroethanolic extract exhibited the highest free radical scavenging activity in DPPH., ABTS.+ and NO. assays showing IC50 as 293.77, 43.62 and 32.58 μg/ml, respectively. Reduced symptoms of radiation sickness, decline in body weight and mortality were minimum when mice were pre-treated with hydroethanolic extract at the dose of 1000 mg/Kg.body.weight prior to irradiation with 8 Gy gamma radiation as compared to mice pre-treated with extract at the dose of 250 and 500 mg/Kg.body.weight prior to irradiation with same dose of radiation. Thus, it was Concluded that certain phenolic constituents of B. diffusa roots like quercitin, caeffic acid, kempferol etc. and their derivatives act as antioxidant compounds confirming B. diffusa roots a potential source of antioxidant agent. Industrial Relevance: Having noticed with the importance of phytochemicals including flavonoids and phenolic acids as contributing factors to the antioxidant activity and common use of roots of Boerhaavia diffusa in majority of medicinal aspects can be responsible in curing oxidative stress related diseases in human beings. This study perhaps will be helpful in development of the effective drug for providing protection to biological systems against free radical induced damage. Keywords: Radioprotection, Boerrhavia diffusa, Free Radical Scavenging Activity, Dose Reduction Factor, Antioxidants.
Microbial Diversity in Soil under Potato Cultivation from Cold Desert Himalaya, India
Priyanka Sati,Kusum Dhakar,Anita Pandey
ISRN Biodiversity , 2013, DOI: 10.1155/2013/767453
Abstract: Mana village (Chamoli district, Uttarakhand, India), situated in high altitudes (3,238?m above mean sea level) of Indian Himalayan region, represents cold desert climatic conditions. At Mana, potato is grown from May to September, while the site remains snow clad for approximately six months (from October to April). Soil samples, collected from Mana potato fields, were analyzed for cultivable microbial diversity along with the chemical and enzymatic properties. The analysis revealed colonization of soil by microflora in moderate numbers (up to 107?CFU/g soil) with limited species level. 25 morphologically distinct microbial isolates belonging to Gram +ve and Gram ?ve bacteria, actinomycetes, and fungi including yeast were isolated. The bacteria were tentatively identified as species of Bacillus and Pseudomonas, while the majority of the fungal isolates belonged to the species of Penicillium. These microbial isolates possessed plant growth promotion and biocontrol properties assessed mainly in terms of production of indole acetic acid and hydrolytic enzymes and phosphate solubilization. The soil, when used as “inoculum” in plant based bioassays, exhibited positive influence on plant growth related parameters. The limited diversity of cold tolerant microbial species also extends opportunity to understand the resilience possessed by these organisms under low temperature environment. 1. Introduction Microorganisms are ubiquitous in nature; their distribution is governed by environmental specificities. Extreme environmental conditions are not uncommon, and the microbial diversity of such areas is of particular interest because of the superb adaptability of the native microbes. Due to slow growth rate and difficulty of handling, relatively little attention has been given to cold adapted psychrophiles or psychrotolerant microbes. Decrease in microbial population with a concomitant increase in the altitude has been reported [1]. Under low temperature environments, the importance and distinction between psychrophiles and psychrotrophs or psychrotolerants have also been recognized [2]. Psychrotolerant microbes are important in high-altitude agroecosystems since they survive and retain their functionality at low temperature conditions, while growing optimally at warmer temperatures [3]. The Indian Himalayan region (IHR) occupies special place in the mountain ecosystems of the world. The mountain agroecosystems are characterized by difficult terrain, inadequate infrastructure, inaccessibility and marginal societies, lack of irrigation, severe top soil erosion, and
Side effects of selection in laboratory animals
RC Roberts
Genetics Selection Evolution , 1978, DOI: 10.1186/1297-9686-10-1-143b
Europe: history, current situation and control measures for infectious bronchitis
Jones, RC;
Revista Brasileira de Ciência Avícola , 2010, DOI: 10.1590/S1516-635X2010000200009
Abstract: the emergence and nature of different strains of infectious bronchitis virus (ibv) in europe are described. infectious bronchitis (ib) is the most important endemic viral respiratory disease where highly pathogenic newcastle disease and avian influenza are not present. ib was first described in the uk in 1948 and identified as massachusetts type. in the 1970s and 80s new serotypes were reported in holland and elsewhere and new vaccines were developed. the 1990s saw the emergence of the major variant commonly called 793b, again needing a new vaccine. two novel types have been recognised since 2000, italy 02 and qx. italy 02 appears to be well controlled by the use of two different live vaccines (h120 and the 793b-related 4/91) while for qx, associated with nephritis in young birds and silent layers, new vaccines are in development. the use of two vaccines as above is a widely used protocol and is capable of protecting against a wide range of different types. alternative approaches to ib vaccination are discussed. the importance of constant surveillance for prevalent and novel ibv types is emphasised and the value of experimental infections in chickens to determine the pathogenesis and pathology of new types in addition to testing efficacy of vaccines is outlined.
Parametric analysis of rail vehicle parameters influencing ride behavior
RC Sharma
International Journal of Engineering, Science and Technology , 2011,
Abstract: This paper presents the influence of rail vehicle parameters on vertical and lateral ride behavior. The analysis considers coupled vertical-lateral 37 degrees of freedom mathematical model of an Indian Railway General Sleeper ICF coach formulated using Largangian dynamics. Both vertical and lateral irregularities of the railway track, considered as random function of time are incorporated in analysis. The ride analysis of the mathematical model suggests that discomfort frequency range lies from 4 to 10.5 Hz and improvements in the design of rail vehicle coach are required for better ride comfort. It is seen from parametric analysis that car body mass, secondary suspension vertical damping, primary suspension vertical damping and wheel base are the most sensitive parameters influencing vertical ride. While lateral ride is significantly influenced by car body mass, roll & yaw mass moment of inertia and secondary suspension lateral stiffness.
The ageing eye
RC Amod
Continuing Medical Education , 2007,
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