DENGUE INFECTION IN ELDERLY PATIENTS

Abstract. From 2005 to 2013, there were 15 dengue patients aged over 60 years old who were admitted to Photharam Hospital, Ratchaburi, Thailand. Ten were females and five were males. Nine had dengue fever (DF), and 6 had dengue hemorrhagic fever (DHF). A trending shift in age group towards adults has been seen during the past decades. No deaths were seen in these elderly patients with dengue disease, indicating early recognition and effective management of these dengue patients. The trend towards higher age in dengue patients is a problem of concern, which needs further elaboration

Effect of chitosan salts and molecular weight on a nanoparticulate carrier for therapeutic protein

10.1081/PDT-200054388Pharmaceutical Development and Technology102189-196PDTE

Design and characterization of monolaurin loaded electrospun shellac nanofibers with antimicrobial activity

The aim of this study was to elucidate the optimized fabrication factors influencing the formation and properties of shellac (SHL) nanofibers loaded with an antimicrobial monolaurin (ML). The main and interaction effects of formulation and process parameters including SHL content (35%–40% w/w), ML content (1%–3% w/w), applied voltage (9–27 kV) and flow rate (0.4–1.2 ml/h) on the characteristic of nanofibers were investigated through a total of 19 experiments based on a full factorial design with three replicated center points. As a result, the SHL content was the major parameter affecting fiber diameter. Another response result revealed that the SHL content would be also the most significant negative impact on amount of beads. An increase in the concentration of SHL leaded to a reduction in the amount of beads. From the results of characterization study, it was proved that ML might be entrapped between the chains of SHL during the electrospinning process exhibiting an excellent encapsulation. According to the response surface area, small (~488 nm) and beadless (~0.48) fibers were obtained with the SHL and ML contents of 37.5% and 1.1% w/w respectively, at the applied voltage of 18 kV and the flow rate of 0.8 ml/h. In addition, the results of the kill-kinetic studies showed that SHL nanofibers loaded with ML exhibited an excellent antibacterial activity against Staphylococcus aureus, while Escherichia coli was less affected due to the hydrophilic structure of the its outer membrane. ML also exerted an antifungal activity by reducing the number of Candida albicans colonies. Based on their structural and antimicrobial properties, SHL nanofibers containing ML could be potentially used as a medicated dressing for wound treatment. Keywords: Shellac, Monolaurin, Nanofibers, Factorial design, Wound dressing, Electrospinnin

Design and characterization of clindamycin-loaded nanofiber patches composed of polyvinyl alcohol and tamarind seed gum and fabricated by electrohydrodynamic atomization

In this study, we developed a polymeric nanofiber patch (PNP) for topical disease treatment using electrohydrodynamic atomization (EHDA). The nanofibers were prepared using various concentrations of polyvinyl alcohol (PVA) and tamarind seed gum and loaded with clindamycin HCl as a model drug. The precursor polymer solutions were sprayed using the EHDA technique; the EHDA processing parameters were optimized to obtain blank and drug-loaded PNPs. The skin adherence, translucence, and ventilation properties of the prepared PNPs indicated that they are appropriate for topical application. The conductivity of the polymer solution increased with increasing PVA and clindamycin concentrations, and increasing the PVA concentration enhanced the solution viscosity. Based on scanning electron microscopy analysis, the PVA concentration had a pronounced effect on the morphology of the sprayed product. Nanofibers were fabricated successfully when the solution PVA concentration was 10%, 13%, or 15% (w/v). The applied voltage significantly affected the diameters of the prepared nanofibers, and the minimum nanofiber diameter was 163.86 nm. Differential scanning calorimetry and X-ray diffraction analyses indicated that the model drug was dispersed in PVA in an amorphous form. The PNP prepared with a PVA:gum ratio of 9:1 absorbed water better than the PVA-only PNP and the PNP with a PVA:gum ratio of 9.5:0.5. Moreover, the PNPs loaded with clindamycin at concentrations of 1%–3% prohibited the growth of Staphylococcus aureus more effectively than clindamycin gel, a commercially available product. Keywords: Electrohydrodynamic atomization (EHDA), Polymeric nanofiber, Clindamycin, Wound dressin

Characterization of chitosan acetate as a binder for sustained release tablets

10.1016/j.jconrel.2004.06.008Journal of Controlled Release99115-26JCRE

Characterization of Chitosan Acetate as a Binder for Sustained Release Tablets

Abstract A chitosan derivative as an acetate salt was successfully prepared by using a spray drying technique. Physicochemical characteristics and micromeritic properties of spray-dried chitosan acetate (SD-CSA) were studied as well as drug-polymer and excipient-polymer interaction. SD-CSA was spherical agglomerates with rough surface and less than 75 Am in diameter. The salt was an amorphous solid with slight to moderate hygroscopicity. The results of Fourier transform infrared (FTIR) and solidstate 13 C NMR spectroscopy demonstrated the functional groups of an acetate salt in its molecular structure. DSC and TGA thermograms of SD-CSA as well as FTIR and NMR spectrum of the salt, heated at 120 8C for 12 h, revealed the evidence of the conversion of chitosan acetate molecular structure to N-acetylglucosamine at higher temperature. No interaction of SD-CSA with either drugs (salicylic acid and theophylline) or selected pharmaceutical excipients were observed in the study using DSC method. As a wet granulation binder, SD-CSA gave theophylline granules with good flowability (according to the value of angle of repose, Carr's index, and Hausner ratio) and an excellent compressibility profile comparable to a pharmaceutical binder, PVP K30. In vitro release study of theophylline from the tablets containing 3% w/w SD-CSA as a binder demonstrated sustained drug release in all media. Cumulative drug released in 0.1 N HCl, pH 6.8 phosphate buffer and distilled water was nearly 100% within 6, 16 and 24 h, respectively. It was suggested that the simple incorporation of spray-dried chitosan acetate as a tablet binder could give rise to controlled drug delivery systems exhibiting sustained drug release.