Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 5 Articles
Background: Nanotechnology is now considered a promising drug delivery method for orally administered\nhydrophobic drugs to their sites of action. The effect of nanodispersion on cellular transport and accumulation of\nsaquinavir (SQV) was investigated.\nMethods: The transport of five solid drug nanoparticle (SDN) SQV formulations along Caco-2 cell monolayers (CCM)\nwas compared to that of standard SQV. The SDNs were prepared using SQV mesylate (20%), Pluronic F127 (10%)\nplus five other excipients (HPMC, PVP, PVA, Lecithin S75 and Span 80) in different proportions. Cellular accumulation\nin CEM parental and CEMVBL (P-gp overexpressing) cells was conducted to ascertain the effect of nanodispersion\non P-gp mediated efflux of SQV. All SDN formulations were dissolved in water, whereas SQV in DMSO to improve\nsolubility. Quantification was via HPLC.\nResults: From transport results, an SDN sample composed of SQV mesylate/Pluronic F127 plus HPMC (70%) and\nhad a 24% increase in apparent absorption compared to standard SQV, largely driven by a 38% reduction in\nbasolateral to apical permeation. Additionally, the formulation and two others (SQV mesylate/Pluronic F127 alone;\nand + HPMC (65%)/Lecithin [5%]) accumulated more significantly in CEM cells, suggesting enhanced delivery to\nthese cells. Moreover, accumulation and transport of the three SDNs compared well to that of SQV despite being\ndissolved in water, suggestive of improved dissolution. The inclusion of PVA resulted in increased efflux.\nConclusion: The use of HPMC and Pluronic F127 produced SQV SDNs with improved permeation in Caco-2 cells\nand improved accumulation in CEM cells, but negative effects with PVA....
Manufacturing parameters may have a strong impact on the dissolution and disintegration\nof solid dosage forms. In line with process analytical technology (PAT) and quality by design\napproaches, computer-based technologies can be used to design, control, and improve the quality\nof pharmaceutical compacts and their performance. In view of shortcomings of computationally\nintensive finite-element or discrete-element methods, we propose a modeling and simulation\napproach based on numerical solutions of the Noyes-Whitney equation in combination with a cellular\nautomata-supported disintegration model. The results from in vitro release studies of mefenamic\nacid formulations were compared to calculated release patterns. In silico simulations with our\ndisintegration model showed a high similarity of release profile as compared to the experimental\nevaluation. Furthermore, algorithmically created virtual tablet structures were in good agreement\nwith microtomography experiments. We conclude that the proposed computational model is a\nvaluable tool to predict the influence of material attributes and process parameters on drug release\nfrom tablets....
Because of poor solubility and considerable metabolism, vardenafil (VRD) bioavailability\nis 15%. To overcome this obstacle, this study aimed to increase the solubility, hasten the onset of\naction, and mask the unpleasant taste of VRD utilizing..................
Partial solvation parameters (PSP) have much in common with the Hansen solubility\nparameter or with a linear solvation energy relationship (LSER), but there are advantages based on\nthe sound thermodynamic basis. It is, therefore, surprising that PSP has so far not been harnessed\nin pharmaceutics for the selection of excipients or property estimation of formulations and their\ncomponents. This work introduces PSP calculation for drugs, where the raw data were obtained from\ninverse gas chromatography. It was shown that only a few probe gases were needed to get reasonable\nestimates of the drug PSPs. Interestingly, an alternative calculation of LSER parameters in silico did\nnot reflect the experimentally obtained activity coefficients for all probe gases as well, which was\nattributed to the complexity of the drug structures. The experimental PSPs were proven to be helpful\nin predicting drug solubility in various solvents and the PSP framework allowed calculation of the\ndifferent surface energy contributions. A specific benefit of PSP is that parameters can be readily\nconverted to either classical solubility or LSER parameters. Therefore, PSP is not just about a new\ndefinition of solvatochromic parameters, but the underlying thermodynamics provides a unified\napproach, which holds much promise for broad applications in pharmaceutics....
Pore-forming agents have a significant influence on the pore structure of hydrogels. In this\nstudy, a porogenic technique was employed to investigate the preparation of macroporous hydrogels\nwhich were synthesized by radical copolymerization of carboxymethyl xylan with acrylamide and\nN-isopropylacrylamide under the function of a cross-linking agent. Six kinds of pore-forming agents\nwere used: polyvinylpyrrolidone K30, polyethylene glycol 2000, carbamide, NaCl, CaCO3, and\nNaHCO3. The application of these hydrogels is also discussed. The results show that pore-forming\nagents had an important impact on the pore structure of the hydrogels and consequently affected\nproperties of the hydrogels such as swelling ratio and mechanical strength, while little effect was\nnoted on the thermal property of the hydrogels. 5-Fluorouracil was used as a model drug to study the\ndrug release of the as-prepared hydrogels, and it was found that the drug release was substantially\nimproved after using the NaHCO3 pore-forming agent: a cumulative release rate of up to 71.05%\nwas achieved....
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