Study of physicochemical properties of flutamide-loaded Ocimum basilicum microspheres with ex vivo mucoadhesion and in vitro drug release

Drug which shows extensive first pass effect is difficult task that, needs to be solved by formulators in the pharmaceutical science. The low oral bioavailability (49%) of flutamide may be due to poor wettability, low aqueous solubility and extensive first pass effect. The aim of present investigation was to prepare flutamide loaded microspheres and incorporate it into suppositories for rectal delivery to avoid first pass effect and enhance residence time. Flutamide loaded mucoadhesive microspheres of Ocimum Basilicum mucilage (OBM) were prepared using spray drying and characterized by percent production yield, encapsulation efficiency, particle size, zeta potential, polydispersity index, DSC, SEM, XRPD, in vitro drug release and stability studies. Moreover, ex vivo mucoadhesion was investigated using falling liquid film technique to determine the adhesion of microspheres to sheep rectal mucosa. The microspheres had nearly spherical shape and size about 2.53?μm. The encapsulation efficiency and mucoadhesion of optimized formulation MBF10 were found to be 69.6?±?2.3% and 89.01?±?2.18%, respectively. Percent CDR of optimized flutamide loaded mucoadhesive microspheres was found to be 88.7?±?1.3 at 7?h. In conclusion, OBM microparticles based suppository could be used to deliver drug through rectal delivery.     

Development of pellets of nifedipine using HPMC K15 M and κ-carrageenan as mucoadhesive sustained delivery system and in vitro evaluation

Polymeric mucoadhesive pellets of nifedipine were designed using computer software and they were prepared by extrusion-spheronization using HPMC K15M and κ-carrageenan with microcrystalline cellulose. A randomized rotatable two factor central composite design was applied for assessment of influence of two independent variables such as concentration of κ-carrageenan and HPMC K15M on dependent variables. Pellets were characterized by FTIR, DSC, SEM, flow properties, particle size, abrasion resistance, sphericity, drug content, percent production yield, in vitro drug release, ex vivo mucoadhesion, stability studies and similarity factor. The optimized formulation was selected based on criteria of sphericity nearest to 1.0 with maximum cumulative drug release percentage. Formulation NF6 exhibited sufficient porous spheres, free flowing and smooth surface mucoadhesion of 91.34 % and drug content 98.22 ± 0.37 %. Kinetic modeling revealed that the formulation followed the Higuchi model and showed the Quassi-Fickian drug release mechanism. The similarity factor, F2 value, was found to be 74 ± 6 and there was no significant change in drug content and ex vivo mucoadhesion after 90 days at 40 ± 2 °C, and 75 ± 5 % RH clearly indicated the optimized batch NF6 was stable. Thus, it can be concluded that use of κ-carrageenan, microcrystalline cellulose and HPMC K15M at the 20:35:10 w/w ratio could provide an effective carrier for enhancement of sphericity and sustained release of matrix pellets.     

Design of laminate composite layups using genetic algorithms

Fibre-reinforced laminate composites have attractively high stiffnesses and strengths and low densities. However, designing with laminate composites is more difficult than designing with metals because (a) it involves the design of the material itself, and its manufacturing route, at the same time, (b) laminates are highly anisotropic, and (c) they have complex failure modes. The failure modes and anisotropy combine to make design details unintuitively important and small detailed-design oversights have been responsible for most failures in composite structures. Design is the process of converting an idea into information from which a product can be made. Thus the central role of information processing in any design activity implies that software should be able to help. Here we show three different ways in which laminate stacking sequences can be designed.     

Co-processed κ-carrageenan-pectin as pelletizing aid for immediate-release pellets

This study investigates the extrusion-spheronization performance of some mixtures of co-processed κ-carrageenan and pectin (as excipient), and sodium starch glycolate (as superdisintegrant). Attention is focused with an objective to improve the mechanical stability and the dissolution rate of poorly soluble domperidone (as a model drug). Initially, co-processed κ-carrageenan-pectin excipient is prepared with different ratios of κ-carrageenan and pectin. Different marketed brands of κ-carrageenan (Gelcarin, Aquagel and Eugel) were employed and dried by solvent evaporation method. Further characterization was carried out by SEM, XRD and FTIR analysis. Pellets were prepared using extrusion-spheronization technique. Pellets were evaluated for flow properties, particle size, sphericity, tensile strength, friability, disintegration time and in-vitro drug release studies. Solid-state characterization of pellets was also done by FTIR, DSC and SEM analysis. The mechanical stability and dissolution rate of prepared pellets were found to be dependent on the concentration of pectin and type of κ-carrageenan employed in the fabrication of pellets. The pellets made with a high proportion of Eugel showed a very high dissolution rate of domperidone and undergo rapid disintegration validating co-processed k-carrageenan-pectin as a promising pelletizing aid for immediate-release pharmaceutical formulations.     

Platinum degradation mechanisms in proton exchange membrane fuel cell (PEMFC) system: A review

Proton Exchange Membrane Fuel Cells (PEMFCs) have the perspective to intensely decrease global emission through environmentally-friendly potential. This review paper summarizes the degradation of platinum catalyst layer that has become a significant issue in the improvement of PEMFCs. The review intends to categorise and provide a clear understanding between disintegration and agglomerate that occurs during platinum degradation. In each process, different degradation mechanisms and their migration processes are presented. The improvement in platinum degradation as a function of increasing the performance of PEMFC is established. Prospects for addressing platinum degradation through the exploration of further experimental and numerical research are recommended. Lastly, this paper through recommendation attempts to prevent platinum degradation and reduces high costs associated with the replacement of catalysts in the PEMFCs.     

In Situ Micro-mechanical Testing of a PM Nickel-Base Superalloy Weld

Microstructural variations between the bond line and the base alloy of welds have been reported in various nickel-base superalloys that have found their applications as structural materials in aero- and land-based engines. This microstructural variation occurs within 50 to 100 μm of majority of welds. Thus, in order to characterize the strength variations between the weld and the base alloy, mechanical testing at micron level is required. This paper presents the use of a newly developed microtensile testing system for an in situ micro-mechanical testing of a powder metallurgy nickel-base superalloy, RR1000 performed in a focused ion beam scanning electron microscope.