60 research outputs found

    Formulation, preparation and in vitro - in vivo evaluation of compression-coated tablets for the colonic-specific release of ketoprofen

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    The aim of this study was to formulate and prepare compression-coated tablets for colonic release (CR-tablets), and to evaluate the bioavailability of ketoprofen following the administration of a single dose from mini-tablets with immediate release (IR-tablets) compared to CR-tablets. CR-tablets were prepared based on time-controlled hydroxypropylmethylcellulose K100M inner compression-coating and pH-sensitive Eudragit® L 30D-55 outer film-coating. The clinical bioavailability study consisted of two periods, in which two formulations were administered to 6 volunteers, according to a randomized cross-over design. The apparent cumulative absorption amount of ketoprofen was estimated by plasma profile deconvolution. CR-tablets were able to delay ketoprofen’s release. Compared to IR-tablets used as reference, for the CR-tablets the maximum plasma concentration (Cmax) was lower (4920.33±1626.71 ng/mL vs. 9549.50±2156.12 ng/mL for IR-tablets) and the time needed to reach Cmax (tmax) was 5.33±1.63 h for CR-tablets vs. 1.33±0.88 h for IR-tablets. In vitro-in vivo comparison of the apparent cumulative absorption amount of ketoprofen showed similar values for the two formulations. Therefore, the obtained pharmacokinetic parameters and the in vitro-in vivo comparison demonstrated the reliability of the developed pharmaceutical system and the fact that it is able to avoid the release of ketoprofen in the first part of the digestive tract

    Exploring Vacuum Compression Molding as a Preparation Method for Flexible-Dose Pediatric Orodispersible Films

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    In recent years, solid dosage forms have gained interest in pediatric therapy because they can provide valuable benefits in terms of dose accuracy and stability. Particularly for orodispersible films (ODFs), the literature evidences increased acceptability and dose flexibility. Among the various available technologies for obtaining ODFs, such as solvent casting, hot-melt extrusion, and ink printing technologies, the solvent-free preparation methods exhibit significant advantages. This study investigated Vacuum Compression Molding (VCM) as a solvent-free manufacturing method for the preparation of flexible-dose pediatric orodispersible films. The experimental approach focused on selecting the appropriate plasticizer and ratios of the active pharmaceutical ingredient, diclofenac sodium, followed by the study of their impacts on the mechanical properties, disintegration time, and drug release profile of the ODFs. Additional investigations were performed to obtain insights regarding the solid-state properties. The ODFs obtained by VCM displayed adequate quality in terms of their critical characteristics. Therefore, this proof-of-concept study shows how VCM could be utilized as a standalone method for the production of small-scale ODFs, enabling the customization of doses to meet the individual needs of pediatric patients

    Dengue Virus Infection of Aedes aegypti Requires a Putative Cysteine Rich Venom Protein

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    Citation: Londono-Renteria, B., Troupin, A., Conway, M. J., Vesely, D., Ledizet, M., Roundy, C. M., . . . Colpitts, T. M. (2015). Dengue Virus Infection of Aedes aegypti Requires a Putative Cysteine Rich Venom Protein. Plos Pathogens, 11(10), 23. doi:10.1371/journal.ppat.1005202Dengue virus (DENV) is a mosquito-borne flavivirus that causes serious human disease and mortality worldwide. There is no specific antiviral therapy or vaccine for DENV infection. Alterations in gene expression during DENV infection of the mosquito and the impact of these changes on virus infection are important events to investigate in hopes of creating new treatments and vaccines. We previously identified 203 genes that were >= 5-fold differentially upregulated during flavivirus infection of the mosquito. Here, we examined the impact of silencing 100 of the most highly upregulated gene targets on DENV infection in its mosquito vector. We identified 20 genes that reduced DENV infection by at least 60% when silenced. We focused on one gene, a putative cysteine rich venom protein (SeqID AAEL000379; CRVP379), whose silencing significantly reduced DENV infection in Aedes aegypti cells. Here, we examine the requirement for CRVP379 during DENV infection of the mosquito and investigate the mechanisms surrounding this phenomenon. We also show that blocking CRVP379 protein with either RNAi or specific antisera inhibits DENV infection in Aedes aegypti. This work identifies a novel mosquito gene target for controlling DENV infection in mosquitoes that may also be used to develop broad preventative and therapeutic measures for multiple flaviviruses

    Golden Rule of Forecasting: Be Conservative

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    This article proposes a unifying theory, or the Golden Rule, or forecasting. The Golden Rule of Forecasting is to be conservative. A conservative forecast is consistent with cumulative knowledge about the present and the past. To be conservative, forecasters must seek out and use all knowledge relevant to the problem, including knowledge of methods validated for the situation. Twenty-eight guidelines are logically deduced from the Golden Rule. A review of evidence identified 105 papers with experimental comparisons; 102 support the guidelines. Ignoring a single guideline increased forecast error by more than two-fifths on average. Ignoring the Golden Rule is likely to harm accuracy most when the situation is uncertain and complex, and when bias is likely. Non-experts who use the Golden Rule can identify dubious forecasts quickly and inexpensively. To date, ignorance of research findings, bias, sophisticated statistical procedures, and the proliferation of big data, have led forecasters to violate the Golden Rule. As a result, despite major advances in evidence-based forecasting methods, forecasting practice in many fields has failed to improve over the past half-century

    Water insoluble polymers as efficient binder in fluid bed granulation of metoprolol for preparation hydrophilic matrix extendedrelease tablets

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    Objectives. The objective of this study was to investigate the possibility of developing metoprolol extended-release tablets by using hydroxypropyl methylcellulose (HPMC) in order to obtain the hydrophilic matrix and Eudragit NE 40D, Kollicoat SR 30D and Surelease E7 as binders during the granulation process. Material and methods. The extended-release tablets were prepared via fluid bed granulation of metoprolol powder using Eudragit NE 40D / Kollicoat SR 30D / Surelease E7 as binders, followed by compression. The influence of three formulation factors (the type of granulation polymers, the ratio of granulation polymers and the HPMC ratio) on the kinetic metoprolol tartrate release was investigated through a full factorial experimental design. Outcomes. The kinetic release of all 26 formulations was best fitted with Peppas model. According to n values of Peppas equation, the release mechanism of drug consists in water diffusion into the matrix, followed by matrix swelling and erosion. The results also indicated that the formulations containing an increased amount of Eudragit NE (10% or more) as binder in the granulation process presented a satisfactory release rate of metoprolol over 12 hours from the granules incorporated in the hydrophilic matrix. Conclusions. This study demonstrated the possibility of lowering of the burst effect from hydrophilic matrix extendedrelease dosage forms incorporating a freely soluble drug, by granulating the drug with a high amount of Eudragit NE 40D and processing the obtained granules in a hydrophilic matrix by tableting

    Washout coefficients for polydisperse aerosols

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