Development of Novel Octanoyl Chitosan Nanoparticles for Improved Rifampicin Pulmonary Delivery: Optimization by Factorial Design

A novel hydrophobic chitosan derivative, octanoyl chitosan (OC) with improved organic solubility was synthesized, characterized, and employed for the preparation of rifampicin (Rif) encapsulated nanoparticle formulations for pulmonary delivery. OC was characterized to confirm acyl group substitution and cytotoxicity in A549 epithelial lung cells. OC nanoparticles were produced by the double emulsion solvent evaporation technique without cross-linking and characterized for particle size distribution, morphology, crystallinity, thermal stability, aerosol delivery, and drug release rate. OC was successfully synthesized with substitution degree of 44.05 ± 1.75%, and solubility in a range of organic solvents. Preliminary cytotoxicity studies of OC showed no effect on cell viability over a period of 24 h on A549 cell lines. OC nanoparticles were optimized using a 32full factorial design. An optimized batch of OC nanoparticles, smooth and spherical in morphology, had mean hydrodynamic diameter of 253 ± 19.06 nm (PDI 0.323 ± 0.059) and entrapment efficiency of 64.86 ± 7.73% for rifampicin. Pulmonary deposition studies in a two-stage impinger following aerosolization of nanoparticles from a jet nebulizer gave a fine particle fraction of 43.27 ± 4.24%. In vitro release studies indicated sustained release (73.14 ± 3.17%) of rifampicin from OC nanoparticles over 72 h, with particles demonstrating physical stability over 2 months. In summary, the results confirmed the suitability of the developed systems for pulmonary delivery of drugs with excellent aerosolization properties and sustained-release characteristics. © 2018, American Association of Pharmaceutical Scientists

Duodenal Tuberculosis: Radiological Features on Barium Studies and their Clinical Correlation in 28 Cases

BACKGROUND: A retrospective analysis of 28 cases of duodenal tuberculosis (TB) was done to evaluate radiological findings and their value in the diagnosis of the disease. subjects AND METHODS: Upper gastrointestinal and small bowel series of 28 patients with duodenal tuberculosis were analysed for radiological findings. The diagnosis of duodenal TB was confirmed by surgery and biopsy in 18, on the basis of radiological findings and response to treatment in 9, and on the basis of findings on upper gastrointestinal scopy and biopsy in 1 patient. RESULTS: The study included 28 patients (14 males, 14 females). The mean age was 32.1 (range 5-65). Twenty-three (82.2%) patients presented with obstructive symptoms while five manifested with dyspeptic symptoms. Of the latter, 4 had ulcerations in the third and fourth parts of the duodenum. In the remaining patient, the mucosa of the duodenum could not be clearly visualised. Two patients had extrinsic impression at the D2-D3 and D3-D4 segments. In 23 patients with obstructive symptoms, 18 demonstrated luminal narrowing of varying degrees and 5 had a sharp band-like cut-off at the third part of the duodenum. Of the 18 patients with luminal narrowing, 13 had extrinsic compression, 12 had proximal dilatation and 14 had ulcerations mainly in the second and third parts of the duodenum. Biliary involvement was seen in 3 patients without any signs or symptoms directly referable to the biliary involvement. CONCLUSION: Though duodenal TB lacks specific radiological features, barium studies help to localise and define the area of narrowing and ulcerations and help to confirm the presence of lymph nodes causing compression of the duodenum

Assessment of Diaphragm Function by Ultrasounds

This chapter focuses on thoracic ultrasound as a noninvasive technique for diaphragm morphological and functional assessment, that can be used as an alternative to traditional, more challenging and uncomfortable methods, such as the fluoroscopic sniff test, nerve conduction studies, and electromyography. This chapter firstly focuses attention on the techniques that can be used and on the measurements that can be obtained. Lastly the pathophysiological significance and the potential clinical applications for diagnostic and prognostic purposes are described

MAGNETIC RESONANCE IMAGING OF THE KIDNEY

This chapter describes the imaging techniques for the examination of the kidney using magnetic resonance (MR), from the fundamental morphologic sequences to the advanced applications. The basic MR features of vascular and infectious renal diseases, solid benign and malignant renal tumors, and cystic renal tumors are described. Advanced MR applications are described as a generai introduction to the following chapters describing the different renal pathologies. Cross-sectional imaging plays a criticai role in the detection and workup of renal pathologies. Even if computed tomography (CT) is stili playing the leader, the role of magnetic resonance imaging (MRI) is increasing, thanks to its better tissue contrast resolution and the absence of radiation exposure. Furthermore, MRI can be used as a problem-solving modality when CT findings are nondiagnostic. While MRI has been shown to be useful in the detection and characterization of renal masses, in the staging of cancers, and in the evaluation of urinary tract anomalies and obstructive disease, attempts are being made to use it for assessment of renal function, such as perfusion, glomerular filtration rate, and intrarenal oxygen measurement. Although the nephrogenic systemic fibrosis has been recently recognized, gadolinium contrast agents are still considered safe. They can be used even in atopic patients and in patients with moderate impairment of renal function (estimateci glomerular filtration rate >30 mL/ min/1.73 m2 )