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Biomedical subjects

S Takka

Publications and source records attributed to S Takka.

9 recordsLinked to original sources
PubMed2006

Investigation of colon-specific dosage forms of ondansetron prepared with natural polymers.

The aim of this study was to develop colon-specific delivery systems of ondansetron using natural polymers such as guar gum and sodium alginate. For this purpose colon specific matrix tablets were prepared by a direct compression method. The physical properties of the tablets were tested and in vitro release studies were performed by a flow-through cell apparatus. The amount of polymers affected the in vitro drug release from the matrix tablets. A high amount of polymers provided slow drug release whereas the release of ondansetron from the tablets prepared with low amount of polymers was found to be fast. Ondansetron-alginate and/or guar gum matrix tablet formulations can deliver the drug to the small and large intestine thus these matrix may be a promising system for the reduction of visceral sensitivity and inhibition of motor activity in irritable bowel syndrome (IBS).

Alginates↗
PubMed2003

Influence of methacrylic acid and hydroxypropylmethyl cellulose on the tablet properties and in vitro release of dextromethorphan hydrobromide.

The release of dextromethorphan hydrobromide from matrices containing hydroxypropylmethyl cellulose (HPMC K100LV) and methacrylic acid copolymer (Eudragit L100-55) has been evaluated at different ratios of the polymers. The physicochemical properties (including weight, thickness, crushing strengh, friability and disintegration time) were also determined at 1000, 2000 and 4000 p compression forces. No significant differences in weight uniformity and thickness values were observed between the different formulations. The crushing strength of the tablets increased with increasing compression force and it reached a constant level at 4000 p. The formulations containing only HPMC K100LV resulted in an extended release pattern, however, Eudragit L100-55 alone could not effectively prolong the drug release. A combination of HPMC K100LV and Eudragit L100-55 in a 1:1 ratio at the 40% level provided an almost similar drug release profile than the marketed product.

Acrylic Resins↗
PubMed2001

Effect of anionic polymers on the release of propranolol hydrochloride from matrix tablets.

Anionic polymers, namely Eudragit S, Eudragit L 100-55, and sodium carboxymethylcellulose, were incorporated into hydroxypropylmethylcellulose (HPMC K100M) to modify the drug release from HPMC matrices. The effects of changing the ratio of HPMC to anionic polymers were examined in water and in media with different pH. The dissolution profiles were compared according to release rates. The interaction between propranolol hydrochloride and anionic polymers was confirmed using the UV difference spectra method. The drug release was controlled with the type of anionic polymer and the interaction between propranolol hydrochloride and anionic polymers. The HPMC-anionic polymer ratio also influenced the drug release. The matrix containing HPMC-Eudragit L 100-55 (1:1 ratio) produced pH-independent extended-release tablets in water, 0.1 N HCl, and pH 6.8 phosphate buffer.

Acrylic Resins↗
PubMed2000

Surgical management of tophaceous gout in the hand.

A patient who suffered from severe deforming arthritis secondary to chronic tophaceous gout with multilobular, solid, tender, enlarged subcutaneous nodules and draining tophi in both hands was evaluated and treated by second ray amputation of the most deformed second finger to provide a more functional result.

Amputation, Surgical↗
PubMed1998

Supracondylar process syndrome.

Supracondylar process syndrome of the humerus has received little attention in the orthopaedic literature. This case report presents a patient with this condition.

Adult↗
PubMed1998

Formulation and investigation of nicardipine HCl-alginate gel beads with factorial design-based studies.

The release rate of nicardipine HCl from various alginate gel bead formulations was investigated. The formulations were prepared by utilizing 23 factorial design. The effect of drug:polymer weight ratio, CaCl2 and sodium-alginate concentration on the time for 50% of the drug to be released (t50%) and the drug entrapment efficiency were evaluated with analysis of variance. The mean particle size and the swelling ratio of the beads were determined. The in vitro release studies were carried out by flow-through cell apparatus in different media (pH 1.2, 2.5, 4.5, 7 and 7.5 buffer solutions). Drug:polymer weight ratio and the interaction of drug:polymer weight ratio and CaCl2 concentration had a significant effect on the drug entrapment efficiency. The release of nicardipine was extended with the alginate gel beads, which were prepared in a ratio of 1:1 (drug:polymer). The release of drug from alginate gel beads took place both by diffusion through the swollen matrix and relaxation of the polymer at pH 1.2-4.5. However, the release was due to the diffusion and erosion mechanism at pH 7-7.5.

Alginates↗
PubMedDate not supplied

Calcium alginate microparticles for oral administration: I: Effect of sodium alginate type on drug release and drug entrapment efficiency.

The natural polymers alginate and chitosan were used for the preparation of controlled release nicardipine HCl gel microparticles. The effect of the mannuronic/guluronic acid content and the alginate viscosity on the prolonged action of the microparticles, which were prepared with different types of alginates, were investigated. The mean particle sizes and the swelling ratios of the microparticles were also determined. The in vitro release studies were carried out with a flow-through cell apparatus in different media (pH 1.2, 2.5, 4.5, 7 and 7.5 buffer solutions). The release of nicardipine was extended with the alginate gel microparticles prepared with guluronic acid rich alginate. After the determination of the most appropriate alginate type, the effect of alginate-chitosan complex formation was studied on the release pattern of drug incorporated. It was observed that the alginate-chitosan complex formation reduced the erosion of the alginate-chitosan matrix at pH 7-7.5. The release of drug from the chitosan-alginate gel microparticles took place by both diffusion through the swollen matrix and relaxation of the polymer at pH 1.2-4.5.

Alginates↗
PubMedDate not supplied

Calcium alginate microparticles for oral administration: II. Effect of formulation factors on drug release and drug entrapment efficiency.

The release rate of nicardipine HCl from various alginate microparticles was investigated. Manugel A7B618 which has a high guluronic acid content of 70% and a low polymerization degree of 60-400 was used as alginate. A 2(3) factorial design was utilized for the preparation of the alginate microparticles. The effect of drug:polymer weight ratio, CaCl2 concentration and curing time on parameters such as the time for 50% of the drug to be released (t50%) and the drug entrapment efficiency were evaluated with analysis of variance. The mean particle sizes and the swelling ratios of the microparticles were determined. The in vitro release studies were carried out with a flow-through cell apparatus at different media (pH 1.2, 2.5, 4.5, 7, 7.5 buffer solutions). Drug:polymer weight ratio and the concentration of the crosslinking agent were the influential factors on the release of NC from the alginate microparticles. The release of nicardipine was extended with alginate microparticles prepared in a ratio of 1:1 (drug:polymer weight ratio). The release of drug from alginate microparticles took place by both diffusion through the swollen matrix and relaxation of the polymer at pH: 1.2-4.5. However, the release was due to diffusion and erosion mechanisms at pH 7-7.5.

Administration, Oral↗