Rotating biological contactors : a review on main factors affecting performance

Rotating biological contactors (RBCs) constitute a very unique and superior alternative for biodegradable matter and nitrogen removal on account of their feasibility, simplicity of design and operation, short start-up, low land area requirement, low energy consumption, low operating and maintenance cost and treatment efficiency. The present review of RBCs focus on parameters that affect performance like rotational speed, organic and hydraulic loading rates, retention time, biofilm support media, staging, temperature, influent wastewater characteristics, biofilm characteristics, dissolved oxygen levels, effluent and solids recirculation, stepfeeding and medium submergence. Some RBCs scale-up and design considerations, operational problems and comparison with other wastewater treatment systems are also reported.Fundação para a Ciência e a Tecnologia (FCT

Agro-morphological characterization of upland rice accessions

The agro-morphological characterization is fundamental in order to provide information for plant breeding programs. The aim of the present study was to characterize 146 accessions of upland rice (Oryza sativa L.), based on qualitative and quantitative agro-morphological descriptors. The experiment was conducted in Recife, state of Pernambuco, Brazil, using a randomized block design with three replicates. Polymorphism was observed among 12 of 14 qualitative characters evaluated, whereas significant differences (p < 0.05) were observed for 11 of the 14 analysed quantitative traits. Genetic variance was higher than environmental variance and the average inheritability coefficients were above 80 % for all characters, which ensures the predominance of the genetic components in the differences observed among accessions. On the cluster analysis for qualitative traits the accessions were classified in two groups with a total of 18 duplicates, whereas for the quantitative traits three groups were obtained with few subgroups. The principal component analysis for quantitative traits showed great dispersion of the accessions. The most divergent group of accessions included the genotypes Mitsukasane, Mie, Tomoe mochi, Ooba kirishima and Nourin mochi 6, which showed a higher number of spicklets per plant. There is high variability among the rice accessions from the germplasm collection studied, which presents great importance for breeding programs or for genetic studies on this species

Formulation and evaluation of nano structured lipid carriers for intranasal delivery of buspirone hydrochloride

The aim of this work was to formulate buspirone hydrochloride (BH) NLCs for intranasal administration to improve BH bioavailability. The BH loaded NLCs were prepared by hot high-pressure homogenization technique using Precirol ATO 5, olive oil and tween 80 as solid lipid, liquid lipid and surfactant, respectively. Carbopol 934P and HPMC K4M were used to convert NLCs dispersion into NLCs based in-situ nasal gelling solution to improve its mucoadhesive property for intranasal administration. A factorial design approach was used to study the effect of independent variable (amount of Precirol ATO 5 and olive oil) on the dependent variables (particle size and percentage entrapment efficiency (%EE). The optimized formulation was characterized for particle size, zeta potential, %EE, and surface morphology. Fourier transform infrared (FTIR) spectroscopy was used to study the possible BH-lipid complex formation. Further, viscosity determination, stability studies, in-vitro drug release, ex-vivo skin permeation studies and ex-vivo nasal toxicity studies of BH loaded NLCs nasal gelling solution were carried out. The BH loaded NLCs (batch F8) showed particle size of 111.8nm, %EE of 78.34% and zeta potential of-44.3mV. Scanning electron microscopy (SEM) confirmed spherical shape of NLCs. In vitro drug release and ex vivo skin permeation studies of BH loaded NLCs and BH loaded NLCs in-situ nasal gelling solution showed 71.26% drug permeation

Formulation and Evaluation of Niosomal in situ Nasal Gel of a Serotonin Receptor Agonist, Buspirone Hydrochloride for the Brain Delivery via Intranasal Route

Copyright© Bentham Science Publishers; For any queries, please email at [email protected]. BACKGROUND: Buspirone Hydrochloride is an anxiolytic agent and serotonin receptor agonist belonging to azaspirodecanedione class of compounds used in the treatment of anxiety disorders. It has short half-life (2-3h) and low oral bioavailability (4%) due to extensive first pass metabolism.OBJECTIVE: The nasal mucosa has several advantages viz., large surface area, porous endothelial membrane, high blood flow, avoidance of first-pass metabolism and ready accessibility that lead to faster and higher drug absorption. Keeping these facts in mind, the objective of the present study was to develop Buspirone hydrochloride loaded niosomal in-situ nasal gel.METHODS: Buspirone hydrochloride niosomal in situ nasal gel was formulated, optimized and evaluated with the objective to deliver drug to the brain via intranasal route. Niosomes were prepared by thin film evaporation method and optimized using32 factorial design. Niosomes were characterized for particle size, zeta potential, entrapment efficiency and in vitro drug release. Buspirone hydrochloride loaded niosomes were further incorporated into Carbopol 934P and HPMC K4M liquid gelling system for the formation of in situ gel. The resultant solution was assessed for various parameters, viz., gelling time, gelling capacity, viscosity at pH 5 and pH 6.RESULTS: The vesicle size of all niosomal suspension batches ranges between 168.3 -310.5 nm. The vesicle size of optimized niosomal suspension F5 batch is 181.9±0.36nm. For F5 batch, the value of zeta potential was found to be -15.4 mV; this specifies that prepared niosomes have sufficient surface charge to prevent aggregation of the vesicles. % entrapment efficiency for all batches was found in the range 72.44±0.18% to 87.7±0.66%. The cumulative percent release of niosomal suspension ranges from 66.34±0.39 to 84.26±0.26%. Ex vivo permeation of Buspirone hydrochloride through the sheep nasal mucosa showed that 83.49% w/w drug permeated after 8 h. The SEM and Zeta potential studies showed the formation of stable vesicles.CONCLUSION: Thus, the application of niosomes proved the potential for intranasal delivery of Buspirone hydrochloride over the conventional gel formulations. Overall intranasal drug delivery for Buspirone hydrochloride has been successfully developed

Improving dissolution profile of poorly water-soluble drug using non-ordered mesoporous silica

© 2018 Marmara University Press. The aim of the study was to increase dissolution rate of atorvastatin by the use of mesoporous silica SYLOID® 244 FP. The poorly soluble drug atorvastatin was adsorbed on and/or into SYLOID® 244 FP in the ratios 1:1, 1:1.1.5, 1:2, 1:2.5, 1:3 and 1:3.5 via a wetness impregnation method. The absence of crystalline form and presence of hydrogen bond interaction between atorvastatin and SYLOID® 244 FP is done by Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The atorvastatin loaded matrix lacked in the crystalline form of atorvastatin and it showed improvement in the dissolution rate of ATC. The flowability of the atorvastatin loaded matrix powder was evaluated by bulk density, Carr’s index and angle of repose. This matrix was then processed into a tablet by direct compression method. A 32 full factorial design was applied to investigate the combined effect of two formulation variables - volume of ethanol and amount of SYLOID® 244 FP. The tablets were evaluated for hardness, friability, drug content and drug dissolution studies. The solubility of atorvastatin-loaded matrix was increased up to 4.28 times. Atorvastatin tablet prepared from drug-loaded silica may provide a feasible approach for development of an oral formulation for this poorly water-soluble drug

Formulation, optimization, and evaluation of ketoconazole loaded nanostructured lipid carrier gel for topical delivery

© 2020 Bentham Science Publishers. Objective: Ketoconazole is used in the treatment of superficial and systemic fungal infections. It acts by blocking the synthesis of ergosterol, an essential component of the fungal cell membrane. The purpose of this work was to formulate ketoconazole loaded nanostructured lipid carriers formulation for skin targeting to minimize the adverse side effects and to prolong release. Methods: The ketoconazole loaded nanostructured lipid carriers were optimized using 32 factorial design to evaluate the effects of process and formulation variables. The nanostructured lipid carriers were prepared by melt-dispersion ultra-sonication method. The formulations were finally incorporated into polymeric gels of Carbopol 940 for convenient application. The gels were evaluated comparatively with commercially available formulations of ketoconazole with respect to ex vivo skin permeation and deposition study on human cadaver skin. Results: Nanostructured lipid carriers showed average particle size, zeta potential, and percentage entrapment in the range of 125.8 ± 1.8 to 295.0 ± 3.8 nm,-13.2 ± 1.1 to-30.9 ± 2.2 mV, and 69.47 ± 2.8 to 95.49 ± 4.5, respectively. Thermal studies revealed no drug-excipient incompatibility and amorphi-zation of ketoconazole. Ex vivo study of the gel exhibited prolonged drug release up to 12 h. In vitro drug deposition study showed that the gel formulation can avoid the systemic uptake, better accumulative uptake of the drug, and nonirritant to the skin compared to marketed formulation. Optimized formulation exhibited better antifungal activity when compared to ketoconazole loaded gel and marketed cream (Keto® cream). Histolopathology results indicated no toxic effect on the skin. Conclusions: These results indicate that developed nanostructured lipid-carriers gel formulation represents a promising carrier for topical delivery of ketoconazole, having controlled drug release, and potential of skin targeting