Biomedical subjects

J C Doadrio

Publications and source records attributed to J C Doadrio.

3 recordsLinked to original sources

PubMed2004

Mesoporous SBA-15 HPLC evaluation for controlled gentamicin drug delivery.

Mesoporous silica SBA-15 was prepared to evaluate its application as gentamicin drug delivery system. Two procedures were used to evaluate the delivery: calcined powder and disk conformed. The samples were charged with gentamicin sulphate and the experiments were carried out in vitro. No significant difference between powder and disk was observed in the tests. The release profiles exhibited a pronounced initial burst release effect of 60%, followed by a very slow release pattern. A new HPLC method was employed for calculated gentamicin amount in the delivery test. This method requires a small amount of sample, very advisable in these kinds of assays.

Chromatography, High Pressure Liquid↗

PubMed2004

Calcium sulphate-based cements containing cephalexin.

Cephalexin containing gypsum and apatite/gypsum cements have been synthesised. The presence of cephalexin into the cements does not alter neither the physico-chemical behaviour of the cements nor produce structural changes on them. These cements behave as drug delivery systems when soaked in simulated body fluid. The release of the drug is different depending on the composition. For gypsum cements, the cephalexin is quickly released, helped by a dissolution process of the matrix, whereas the drug release is more controlled by the hydroxyapatite presence in hydroxyapatite/gypsum samples. Apatite containing cements do not only show a different drug release process, also the paste viscosity is lower and a faster formation "in vitro" of an apatite-type layer on their surface is observed.

Anti-Bacterial Agents↗

PubMed1993

Binding of Pt-pentamidine to nucleosomal DNA. Studies of the antiproliferative activity of the drug against human cancer cells.

In the present paper we present data showing that the effect of the binding of the antitumour drug Pt-pentamidine to nucleosomal DNA is the opposite to that of the cis-DDP compound since it causes strong stabilization of the double helix to heat denaturation and because in nucleosome:Pt-pentamidine complexes the nucleosomal denatured DNA is able to reassociate at 71 degrees C. Upon binding, the pentamidine ligand, by itself, also produces stabilization of the nucleosomal DNA but the effect is lower than that induced by Pt-pentamidine. It seems that in Pt-pentamidine:nucleosome complexes about 50% of the adducts are formed during the first hour of incubation of the nucleosomes with the drug since the increase in Tm of the DNA of these complexes is 53% of the total increase in Tm of the DNA of the Pt-pentamidine:nucleosome complexes formed in 48 h. The 'in vitro' screening of the antiproliferative activity of Pt-pentamidine against 60 tumour cell lines indicated that this antitumour compound shows higher antiproliferative activity against small cell lung, non-small cell lung and melanoma cancer lines than against the rest of the cell lines.

Antineoplastic Agents↗