Biomedical subjects

T Sannan

Publications and source records attributed to T Sannan.

4 recordsLinked to original sources

PubMed1990

Effect of interpolymer complex formation on bioadhesive property and drug release phenomenon of compressed tablet consisting of chitosan and sodium hyaluronate.

The bioadhesion property of tablets consisting of chitosan (CS) and sodium hyaluronate (HA) was investigated using a lyophilized porcine dermis as a model of mucous membrane. Release phenomena of brilliant blue FCF (BBL) from the CS-HA tablets were also studied. BBL was employed as a model compound of water-soluble drugs. Strong adhesion forces were observed when the tablets were prepared from HA alone or a physical mixture of CS and HA. The adhesion of CS tablets was also obtained but it was rather weak. No effect of pH values in the media was observed on the adhesion force in these tablets. On the other hand, the release rate of BBL from CS-HA tablets was greatly affected by the change of the polymer mixing ratio, suggesting a possible interaction between CS and HA in the tablet following water penetration into the tablet.

Adhesiveness↗

PubMed1989

Buoyant sustained release granules based on chitosan.

Attempts to develop sustained release intragastric 'floating' granules based on chitosan are described, using chitosan of different degrees of deacetylation (chitosan H and L), in granular form or in laminated preparations. The granules were made from chitosan H (chitosan H granules), from a 1:1 mixture of chitosan H and L (1:1 mixture granules), from a 1:2 mixture of chitosan H and L (1:2 mixture granules), or from chitosan L (chitosan L granules). They were prepared by a method involving deacidification, had internal cavities, were immediately buoyant in both acidic and neutral fluids, and gave sustained release of prednisolone (used as a model drug). The laminated preparations, composed of a chitosan granule layer and a chitosan L membrane, were also immediately buoyant in the same fluids, and also provided sustained release of the model drug. The release properties were controlled by regulating the chitosan L content of the granules, or the chitosan L membrane thickness of the laminate. In an absorption study using beagle dogs, sustained drug absorption from these preparations was obtained.

Animals↗

PubMed1988

Buoyant sustained release tablets based on chitosan.

This study attempted to develop sustained release intragastric 'floating' tablets based on chitosan. Two kinds of chitosan with different degrees of deacetylation (chitosan H and L) were used, and two types of preparations (types A and B) were examined. Type A preparations, i.e. directly compressed tablets using a mixture of sodium hydrogen carbonate and citric acid, were buoyant immediately and gave sustained release of prednisolone (as model drug) in acidic dissolution fluid. Type B preparations, i.e. preparations composed of a directly compressed layer and a chitosan H membrane layer enclosing carbon dioxide (a foamy membrane layer), quickly developed buoyancy and also provided sustained release of drug. The drug release rate from the preparation using chitosan L was slower than that from the preparation using chitosan H. In an absorption study using beagle dogs, sustained drug absorption from Type B preparations was obtained.

Animals↗

PubMed1986

Use of chitosan and hydroxypropylchitosan in drug formulations to effect sustained release.

This study was an attempt to develop implantable sustained release forms of drugs, based on formulations containing chitosan, a biodegradable polymer from a natural source, and hydroxypropylchitosan (HP-chitosan), its water-soluble derivative. The possibilities were explored using uracil as a model for anticancer drugs. Enzymatic degradation of chitosan and HP-chitosan was first confirmed in vitro (using lysozyme) and in vivo by implanting both materials subcutaneously into the backs of rats. Then, using an in vitro dissolution test, we found that the release rate of uracil from chitosan membranes could be altered by the addition of HP-chitosan. Film- and stick-type implantable dosage forms of chitosan containing uracil were prepared by the 'Extrusion-in-Air' method. These gave rise to sustained release of uracil in vitro and in vivo. We conclude that chitosan and HP-chitosan have a potential as biocompatible and biodegradable vehicles in the preparation of implantable sustained release dosage forms of anticancer drugs.

Chemical Phenomena↗