Current Issue : January - March Volume : 2018 Issue Number : 1 Articles : 5 Articles
The aim of present work is to determine and analyse the kinetics of drug release from the matrix tablet by employing\nvarious mathematical models. A study was done with Carbidopa and Levodopa ER tablets, 50 mg/200 mg by employing\nwet granulation technique using Hydroxypropyl methylcellulose and Hydroxypropyl cellulose as matrix forming polymer.\nThe in-vitro drug release profile was carried out in 0.1 N HCl (900 mL) using USP dissolution apparatus II (Paddle)\nat 50 rpm at an extended time period of 0.5, 0.75, 1, 1.5, 2, 2.5, 3 and 4 hours. The drug release data was obtained,\nquantitatively correlated and interpreted with various mathematical models viz. Zero order model, first order model,\nHiguchi model, Hixson-Crowell model and Korsmeyer-Peppas model and evaluated to understand the kinetics of drug\nrelease. The criterion for the most suitable model was based on the high degree of coefficient of correlation of drug\nrelease profile of Carbidopa Levodopa ER Tablet. Hence, finally concluded as the drug release pattern of Carbidopa\nLevodopa ER Tablets, 50 mg/200 mg was best fitted with Higuchi square root model and follows Higuchi drug release\nkinetics which is diffusion controlled....
Mesoporous silica materials are promising nanocarriers for the development of drug delivery systems. In this study, the influence\nof pore size, volume, surface area, and doping the silica framework on the release kinetics of a model drug, metoprolol, has been\nstudied. 20% or 50% wt. therapeutic agent was loaded into the carrier mesopores through incipient wetness impregnation. The\ncarriers and drug-loaded samples have been characterized by small- and wide-angle X-ray diffraction, FT-IR spectroscopy, scanning\nelectron microscopy, and nitrogen adsorption-desorption isotherms. The in vitro release profiles have been fitted using a threeparameter\nkinetic model and they have been explained in terms of the release rate during the burst and sustained release stages and\nthe fraction of drug molecules released during the burst stage. The silica framework doping with aluminum was found to decrease\nthe amount of drug released in the burst stage, without affecting the other kinetic parameters. The therapeutic agent release rates\ndepend mainly on the pore size and volume of the mesoporous carriers and drug-loaded samples....
Porous oligolactide-hydroxyapatite composite scaffolds were obtained by stereolithographic fabrication. Gentamicin was then\ncoated on the scaffolds afterwards, to achieve antimicrobial delivery ability to treat bone infection. The scaffolds examined by\nstereomicroscope, SEM, and �¼CT-scan showed a well-ordered pore structure with uniform pore distribution and pore\ninterconnectivity. The physical and mechanical properties of the scaffolds were investigated. It was shown that not only porosity\nbut also scaffold structure played a critical role in governing the strength of scaffolds. A good scaffold design could create proper\norientation of pores in a way to strengthen the scaffold structure. The drug delivery profile of the porous scaffolds was also\nanalyzed using microbiological assay. The release rates of gentamicin from the scaffolds showed prolonged drug release at the\nlevels higher than the minimum inhibitory concentrations for S. aureus and E. coli over a 2-week period. It indicated a potential\nof the scaffolds to serve as local antibiotic delivery to prevent bacterial infection....
Radiolabeled tracers targeting the prostate-specific membrane antigen (PSMA) have become\nimportant radiopharmaceuticals for the PET-imaging of prostate cancer. In this connection, we\nrecently developed the fluorine-18-labelled PSMA-ligand [18F]PSMA-1007 as the next generation\nradiofluorinated Glu-ureido PSMA inhibitor after [18F]DCFPyL and [18F]DCFBC. Since radiosynthesis\nso far has been suffering from rather poor yields, novel procedures for the automated radiosyntheses\nof [18F]PSMA-1007 have been developed. We herein report on both the two-step and the novel\none-step procedures, which have been performed on different commonly-used radiosynthesisers.\nUsing the novel one-step procedure, the [18F]PSMA-1007 was produced in good radiochemical yields\nranging from 25 to 80% and synthesis times of less than 55 min. Furthermore, upscaling to product\nactivities up to 50 GBq per batch was successfully conducted. All batches passed quality control\naccording to European Pharmacopoeia standards. Therefore, we were able to disclose a new, simple\nand, at the same time, high yielding production pathway for the next generation PSMA radioligand\n[18F]PSMA-1007. Actually, it turned out that the radiosynthesis is as easily realised as the well-known\n[18F]FDG synthesis and, thus, transferable to all currently-available radiosynthesisers. Using the new\nprocedures, the clinical daily routine can be sustainably supported in-house even in larger hospitals\nby a single production batch....
The melt-extrusion process is utilized in the pharmaceutical arena for the manufacturing\nof a variety of dosage forms and formulations, including solid dispersions. This technology is\nconsidered an efficient and continuous dosage form manufacturing method. However, there are\npotential challenges mainly because, during hot-melt extrusion, polymers are subject to mechanical\nand thermal degradation. Mechanical degradation may be induced by the shear effects imposed\nby the rotating screw. Thermal degradation results from high temperatures and includes random\nscission, scission from the ends of the polymer and unzipping of substitute groups. This paper\nendeavors to understand the impact of thermal and/or mechanical components of the melt-extrusion\nprocess on the stability of a pH sensitive polymer, namely Shellac. Correlation between the screw\nspeeds and processing temperature profile was examined in the context of the overall degradation\nprofile of the polymer. The results suggest that the processing stability of Shellac was reliant on\noptimization of screw speed (rpm) and process temperature....
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