PubMed Health⌕ Search

Biomedical subjects

Ferdinando Giordano

Publications and source records attributed to Ferdinando Giordano.

8 recordsLinked to original sources
PubMed2006

Solid-state chemistry and particle engineering with supercritical fluids in pharmaceutics.

The present commentary aims to review the modern and innovative strategies in particle engineering by the supercritical fluid technologies and it is principally concerned with the aspects of solid-state chemistry. Supercritical fluids based processes for particle production have been proved suitable for controlling solid-state, morphology and particle size of pharmaceuticals, in some cases on an industrial scale. Supercritical fluids should be considered in a prominent position in the development processes of drug products for the 21st century. In this respect, this innovative technology will help in meeting the more and more stringent requirements of regulatory authorities in terms of solid-state characterisation and purity, and environmental acceptability.

Albuterol↗
PubMed2004

The surface roughness of lactose particles can be modulated by wet-smoothing using a high-shear mixer.

The surface morphology of a-lactose monohydrate particles was modified by a new wet-smoothing process performed in a high-shear mixer using solvents. Successive steps of wetting and drying of lactose powders during rolling in the mixer's cylindrical bowl were performed. Smoothed particles were tested for size distribution, flow, and packing. The wet-smoothing process flattened the surface and rounded the edges of lactose particles. In comparison with original lactose, an improvement of powder packing and flow properties was evidenced. When the process was performed in the presence of a ternary agent such as magnesium stearate, the smoothing was improved. The evolution of rugosity during the smoothing process was assessed through a fractal descriptor of SEM picture. Atomic force microscopy and surface area measurements quantified the surface rugosity. A very significant reduction of the rugosity, more remarkable in the presence of magnesium stearate, was measured. This new process of powder wet-smoothing allows the preparation of lactose particles with different degrees of smoothed surface for the control of flow and packing properties and particle-particle interactions.

Lactose↗
PubMed2004

Modeling of drug release from partially coated matrices made of a high viscosity HPMC.

A mathematical model able to describe the release kinetics of two model drugs (Diprophylline and Theophylline) from partially coated hydroxypropylmethylcellulose (HPMC, Methocel) K4M) matrices is presented. As solvent interaction with the system and drug release can only take place in one direction, the physical frame to be modeled turns out simpler. The model was developed starting from the established equation describing drug dissolution and taking into account the resistance to drug release given by the presence of a growing gel barrier around a matrix system. The model fits the release data obtained from both series of hydrophilic matrices containing increasing amounts (from 0.2 to 0.8 mass ratio) of the two xanthine derivatives. Differences were found in drug release rate according to the different solubility of the actives. Interestingly, however, there is no further reduction in the outer gel layer permeability when the polymer mass fraction exceeds a certain value, with both Theophylline and Diprophylline systems. Results confirm the importance of the fraction of the glassy/rubbery interface held by the active substance in defining the release rate from hydrophilic systems.

Drug Delivery Systems↗
PubMed2004

Drug-beta-cyclodextrin containing pellets prepared with a high-shear mixer.

This work was aimed at investigating the preparation of beta-cyclodextrin-microcrystalline cellulose pellets by means of a high-shear mixer, both in the absence or in the presence of ibuprofen as model drug. Drug loading of pellets was accomplished by means of two alternative techniques: 1) solution layering or 2) powder layering. The prepared pellets were characterised in terms of size distribution, shape factor, friability and dissolution rate. The interaction between ibuprofen and beta-cyclodextrin was monitored by Differential Scanning Calorimetry (DSC). Micro Fourier Transform Infrared spectroscopy (MicroFTIR) was applied to determine the distribution of components within each pellet on a micro scale. Pellets with narrow size distribution and containing up to about 90% of BCD were prepared using water as binder. The process yield resulted around 84 and 63% for drug-free and medicate pellets respectively. Drug loaded pellets with favourable technological and biopharmaceutical characteristics can be obtained both by powder or solution layering techniques. The latter proved to be more suitable for producing pellets with high drug contents, reduced friability and high drug dissolution rates.

Cellulose↗
PubMedDate not supplied

Renal ultrastructural findings in Anderson-Fabry disease.

Anderson-Fabry disease (AFd) is caused by an X-linked inborn error in the glycosphingoLipid metabolic pathway due to an enzymatic defect in a lysosomal hydrolase: alpha-galactosidase A. The defect results in the progressive accumulation of neutral glycosphingolipids in most body fluids and several tissues. The clinical manifestations of AFd are related to organ damage and, obviously, are more severe in hemizygous males than in heterozygous females. In the third decade of life, the course of the disease involves severe deterioration of kidney function progressing to end-stage renal failure. All kind of cells of renal structures are filled with glycosphingolipid deposits. Electron microscopic studies document typical intracytoplasmic osmiophilic bodies with a characteristic "zebra" or "onion-skin" appearance due to concentric lamellation of alternating clear and dark layers. Clinical interest in Fabry patients is related to recent advances in treatment with an intravenous specific enzyme to modify the biochemical error of the glycosphingolipid catabolic pathway.

Chromosomes, Human, X↗
PubMedDate not supplied

Glomerular changes in hereditary single-gene diseases.

Molecular genetics has strongly influenced clinical medicine and particularly nephrology. Several gene mutations of single-gene hereditary nephropathies have been recently identified. These data are useful to develop methods of diagnosis and treatment, but also to understand the pathogenesis of these particular disorders. In this review we focused on several monogenic hereditary renal diseases inducing nephrotic syndrome and other hereditary diseases with renal involvement and progression towards end-stage renal failure.

Genetic Diseases, Inborn↗
PubMedDate not supplied

Renal involvement in Anderson-Fabry disease.

Anderson-Fabry disease (AFd) is a rare X-linked lisosomal storage disorder of glycosphingolipid (GL) metabolism, caused by a deficiency of the activity of alpha-galactosidase A (alpha-gal A). The progressive accumulation of GL in tissues results in the clinical manifestations of the disease, that are more evident in hemizygous males, and include characteristic skin lesions (angiokeratomas), neurological symptoms (acroparesthesia), ocular features (cornea verticillata), cardiac involvement (left ventricular enlargement, conduction abnormalities), cerebrovascular manifestations (thromboses, hemorrhage, etc.), and kidney involvement with progression to end-stage renal failure (ESRF). ESRF is a common manifestation in hemizygous males (3rd-5th decade) and death occurs around the 5th decade of life because of severe cardiac and/or cerebrovascular complications. Heterozygous females have an attenuated form of this systemic disease. In the kidney, accumulation of GL occurs in the endothelial cells of every vessel, in the epithelial cells of every tubular segment, and in all kinds of glomerular cells. The broad spectrum of renal lesions is a pathophysiological continuum with progressive impairment in the renal function related to continuous intracellular deposition of GL. Electron microscopic study of renal biopsies shows typical osmiophilic inclusion bodies in the cytoplasm of all kind of renal cells, characterized by concentric lamellation of clear and dark layers (35-50 A of periodicity). ESRF is treated by dialysis and kidney transplantation: neither treatment modifies the progression of the cardiovascular and cerebrovascular lesions due to progressive GL deposition. The outcome of kidney transplantation seems to be similar to that found in other non-diabetic patients, but the survival rate on dialysis is lower than in patients with other causes of ESRF. Nowadays, treatment with enzyme replacement infusion with purified alpha-Gal A, produced by a genetically engineered human cell line or Chinese hamster ovocytes, seems to be effective and safe.

Adult↗