Development And In Vitro Evaluation Of Pantoprazole-Loaded Microspheres

Pantoprazole is a proton pump inhibitor prodrug used in the treatment of gastric ulcers and gastroesophageal disease. Pantoprazole must be absorbed in the gastrointestinal tract and because it is unstable under acidic conditions, enteric delivery systems are required. The purpose of this study was to prepare pantoprazole-loaded microspheres by emulsion-solvent evaporation technique using two different types of enteric-coating polymers: Eudragit S 100 and hydroxypropyl methylcellulose phtalate. The microspheres have been characterized in terms of their morphology, encapsulation efficiency, and ability of stabilizing pantoprazole in acidic media. Pantoprazole determinations were carried out using a validated spectrophotometric method for the analysis of drug in dissolution media. All microspheres, except F2 formulation, were successfully obtained. The in vitro assay showed that especially F1 and F4 microspheres were more effective in protecting the drug than F3 microspheres in acidic media.WoSScopu

Sea-Bottom Observations from the Western Escarpment of the Sea of Marmara

The western escarpment of the Sea of Marmara has recently been recognized as the site of intensive gas emissions escaping from the seafloor. Visual observations with the Nautile submersible indicate that gas escapes from elongated tensile cracks oriented to the northwest in the direction of the maximum principal stress. Here, we report results from a 25-day test in 2007 with four ocean-bottom seismometers (OBSs) showing that this area is also characterized by microseismic activity. A cluster of 13 small-magnitude earthquakes aligned northwest occurred in less than 30 hr at shallow crustal depth below the western slope of the Tekirdag basin. The only two focal mechanisms resolvable using land and sea-bottom data reveal normal faulting with strike-slip components, consistent with the stress field expected in this area. It is suggested that tectonic strain below the western slope of the Tekirdag basin contributes to maintaining a high permeability in fault zones and that the fault network provides conduits for deep-seated fluids to rise up to the seafloor

Development of Microsponges for Topical Delivery of Mupirocin

The goal of the present study was to develop and evaluate microsponge-based topical delivery system of mupirocin for sustained release and enhanced drug deposition in the skin. Microsponges containing mupirocin were prepared by an emulsion solvent diffusion method. The effect of formulation and process variables such as internal phase volume and stirring speed on the physical characteristics of microsponges were examined on optimized drug/polymer ratio by 32 factorial design. The optimized microsponges were incorporated into an emulgel base. In vitro drug release, ex vivo drug deposition, and in vivo antibacterial activity of mupirocin-loaded formulations were studied. Developed microsponges were spherical and porous, and there was no interaction between drug and polymer molecules. Emulgels containing microsponges showed desired physical properties. Drug release through cellulose dialysis membrane showed diffusion-controlled release pattern and drug deposition studies using rat abdominal skin exhibited significant retention of active in skin from microsponge-based formulations by 24 h. The optimized formulations were stable and nonirritant to skin as demonstrated by Draize patch test. Microsponges-based emulgel formulations showed prolonged efficacy in mouse surgical wound model infected with S. aureus. Mupirocin was stable in topical emulgel formulations and showed enhanced retention in the skin indicating better potential of the delivery system for treatment of primary and secondary skin infections, such as impetigo, eczema, and atopic dermatitis

Cellulose-Based Matrix Microspheres of Prednisolone Inclusion Complex: Preparation and Characterization

The purpose of the present investigation was to encapsulate pure prednisolone (PRD) and PRD–hydroxypropyl-β-cyclodextrin (HPβCD) complex in cellulose-based matrix microspheres. The system simultaneously exploits complexation technique to enhance the solubility of low-solubility drug (pure PRD) and subsequent modulation of drug release from microspheres (MIC) at a predetermined time. The microspheres of various compositions were prepared by an oil-in-oil emulsion–solvent evaporation method. The effect of complexation and presence of cellulose polymers on entrapment efficiency, particle size, and drug release had been investigated. The solid-state characterization was performed by Fourier transform infrared spectroscopy, thermogravimetry, differential scanning calorimetry, and powder X-ray diffractometry. The morphology of MIC was examined by scanning electron microscopy. The in vitro drug release profiles from these microspheres showed the desired biphasic release behavior. After enhancing the solubility of prednisolone by inclusion into HPβCD, the drug release was easily modified in the microsphere formulation. It was also demonstrated that the CDs in these microspheres were able to modulate several properties such as morphology, drug loading, and release properties. The release kinetics of prednisolone from microspheres followed quasi-Fickian and first-order release mechanisms. In addition to this, the f2-metric technique was used to check the equivalency of dissolution profiles of the optimized formulation before and after stability studies, and it was found to be similar. A good outcome, matrix microspheres (coded as MIC5) containing PRD–HPβCD complex, showed sustained release of drug (95.81%) over a period of 24 h