DEVELOPMENT OF OLMESARTAN MEDOXOMIL-LOADED CHITOSAN MICROPARTICLES: A POTENTIAL STRATEGY TO IMPROVE PHYSICOCHEMICAL AND MICROMERITIC PROPERTIES

Objective: The objective of the present research was to improve physicochemical and micromeritic properties of Olmesartan Medoxomil (OLM), BCS class II antihypertensive drug by loading in Chitosan (CH) microparticles.Methods: The 32 full factorial design was assigned for microparticles prepared by single emulsion technique method using CH, a natural polymer and Glutaraldehyde (GA) as cross linking agent. Developed microparticles were characterized for Micromeritic properties, morphology by Scanning Electron Microscopy (SEM), drug entrapment efficiency, in vitro drug release, and interaction studies Fourier transfer infrared spectroscopy (FTIR) & Differential Scanning Calorimetry (DSC), drug crystallinity study by X-ray diffractometry (XRD) & DSC.Results: Maximum entrapment efficiency was found 61.76% for maximal CH and lower GA concentration. Saturation solubility of microparticles was increased by 13.74 times to that of pure OLM. FTIR showed compatibility between drug and polymer. XRD, DSC and SEM studies confirmed reduction in crystallinity of drug. It led to increase in dissolution profile of the drug and showed 92.61% of drug release in 120 min. These microparticle preparations also helped in improving micromeritic properties like bulk density, tapped density, the angle of repose, Hausner's ratio and Carr's index.Conclusion: The results obtained in the present work demonstrate the potential use of CH to modulate physicochemical and micromeritic properties of OLM especially obtaining significant improvement in dissolution rate. Â

Absolute photoionization cross sections and resonance structure of doubly ionized silicon in the region of the 2p-1 threshold: experiment and theory

We present the absolute photoionization cross section of doubly ionized silicon as a function of photon energy. These were obtained by merging a Si2+ ion beam generated in an electron cyclotron resonance source with monochromatized synchrotron radiation from an undulator. The photoion yield measurements were carried out in the photon energy range between 95 eV and 170 eV, i.e., the region corresponding to the excitation followed by the ionization (threshold ∼133.8eV) of an inner-subshell 2p electron. Resonance structure due to 2p excitation in the 2p63s3p3P metastable state was also observed with its contribution to the total cross section not exceeding 3%. Calculation of the 2p photoionization continuum cross section as a function of photon energy was carried out using the relativistic random-phase approximation (RRPA) and agreed very well with the corresponding measurements. The resonance structure in the 3s cross section below the 2p threshold was found to be in good agreement with the multiconfiguration atomic structure calculations of Sayyad et al. [J. Phys. B 28, 1715 (1995)], while the corresponding RRPA-RMQDT (relativistic multi-channel quantum-defect theory) calculations proved less successful

Insertion of a foldable hydrophobic IOL through the trabeculectomy fistula in cases with Microincision cataract surgery combined with trabeculectomy

BACKGROUND: The use of conventional foldable hydrophobic intraocular lenses (IOLs) in microincision cataract surgery (MICS) currently requires wound enlargement. We describe a combined surgical technique of MICS and trabeculectomy with insertion of a foldable IOL through the trabeculectomy fistula. METHODS: After completion of MICS through two side port incisions, a 3.2 mm keratome is used to enter the anterior chamber under the previously outlined scleral flap. An Acrysof multi piece IOL (Alcon labs, Fort Worth, Tx) is inserted into the capsular bag through this incision. The scleral flap is then elevated and a 2 × 2 mm fistula made with a Kelly's punch. The scleral flap and conjunctival closure is performed as usual. RESULTS: Five patients with primary open angle glaucoma with a visually significant cataract underwent the above mentioned procedure. An IOL was implated in the capsular bag in all cases with no intraperative complications. After surgery, all patients obtained a best corrected visual acuity of 20/20, IOL was well centered at 4 weeks follow up. The mean IOP (without any antiglaucoma medication) was 13.2 + 2.4 mm Hg at 12 weeks with a well formed diffuse filtering bleb in all the cases. CONCLUSION: The technique of combining MICS with trabeculectomy and insertion of a foldable IOL through the trabeculectomy fistula is a feasible and valuable technique for cases which require combined cataract and glaucoma surgery

Risk Factors for Tube Shunt Exposure: A Matched Case-Control Study

Purpose. To evaluate potential risk factors for developing tube shunt exposure in glaucoma patients. Patients and Methods. Forty-one cases from 41 patients that had tube shunt exposure from 1996 to 2005 were identified from the Robert Cizik Eye Clinic and Bascom Palmer Eye Institute. Each case was matched with 2 controls of the same gender and with tube shunts implanted within 6 months of the index case. Conditional logistic regression was used to determine risk factors. Results. The study cohort includes a total of 121 eyes from 121 patients. The mean age was 63.6 ± 19.7 years, ranging from 1 to 96 years. The average time to exposure was 19.29 ± 23.75 months (range 0.36–85.74 months). Risk factors associated with tube exposure were Hispanic ethnicity (; OR = 3.6; 95% CI, 1.3–9.7), neovascular glaucoma (; OR = 28.5; 95% CI, 2.6–316.9), previous trabeculectomy (; OR = 5.3; 95% CI, 1.6–17.7), and combined surgery (; OR = 3.7; 95% CI, 1.1–12.7). Conclusions. Hispanic ethnicity, neovascular glaucoma, previous trabeculectomy, and combined surgery were identified as potential risk factors for tube shunt exposure. These potential risk factors should be considered when determining the indication for performing tube shunt implantation and the frequency of long-term followup

Improving the biopharmaceutical attributes of mangiferin using vitamin E-TPGS co-loaded self-assembled phosholipidic nano-mixed micellar systems

The current research work encompasses the development, characterization, and evaluation of self-assembled phospholipidic nano-mixed miceller system (SPNMS) of a poorly soluble BCS Class IV xanthone bioactive, mangiferin (Mgf) functionalized with co-delivery of vitamin E TPGS. Systematic optimization using I-optimal design yielded self-assembled phospholipidic nano-micelles with a particle size of  80% of drug release in 15 min. The cytotoxicity and cellular uptake studies performed using MCF-7 and MDA-MB-231 cell lines demonstrated greater kill and faster cellular uptake. The ex vivo intestinal permeability revealed higher lymphatic uptake, while in situ perfusion and in vivo pharmacokinetic studies indicated nearly 6.6- and 3.0-folds augmentation in permeability and bioavailability of Mgf. In a nutshell, vitamin E functionalized SPNMS of Mgf improved the biopharmaceutical performance of Mgf in rats for enhanced anticancer potency

Determination of suitable size of Rutilus frisii kutum for releasing by evaluation of osmotic regulation ability

The study was done in Nutrition and Live Food Station was located in Bandar Anzali Ghaziyan. Juveniles weighted average 0.5, 1, 2.5, 5, 10, 15 and 20 g were randomly selected in three water conditions with a salinity of 11 ppt (Caspian sea water), water 7 ppt and freshwater (with three replicates per group) were included. At intervals of 0, 3, 6, 12, 24, 72, 168, 240 hours, blood samples were heparinized capillary tubes by caudal juveniles and ion concentrations Mg, Ca,Cl using the spectrophotometer and sodium and potassium ions with Flaym photometry (flame photometric), the osmotic pressure of blood plasma by osmometer and cortisol levels were measured by RIA method. To study the microstructure of gill and kidney tissue for each treatment , tissue samples by classical histological methods and stained with hematoxylin - eosin slides were prepared. The frequency and location of the enzyme Na^+, K^+ - ATPase and chloride cells with immunohistochemical localization was performed. Studies micrometric gill chloride cells and renal glomerular networks by software Image tool (version 2.0) was performed. Measurement of enzyme Na^+, K^+-ATPase, by Zaugg (1982) method was conducted. Data analyzed by one-way ANOVA (Oneway ANOVA) with Tukey's test was performed. Overall, the results of measuring ions and osmotic pressure on the tenth day of treatment, the osmotic potential juveniles 2.5, 5, 10, 20 gr in Caspian sea water and all groups except the 0.5 in water of 7 ppt confirmed. But in case of unfavorable conditions for the release in estuaries river and river, fish with weight 1 to 3 release directly to beach (where the salinity is 7 grams per liter) and fishes with weight from 10 to 20 gr to sea. Although suitable river conditions necessary condition for release of juveniles in riverine areas to adaptation juveniles occur gradually

The makeshift city: towards a global geography of squatting

This paper introduces a set of analytical frames that explore the possibilities of conceiving, researching and writing a global geography of squatting. The paper argues that it is possible to detect, in the most tenuous of urban settings, ways of thinking about and living urban life that have the potential to reanimate the city as a key site of geographical inquiry. The paper develops a modest theory of ‘urban combats’ to account for the complexity and provisionality of squatting as an informal set of practices, as a makeshift approach to housing and as a precarious form of inhabiting the city