Biomaterial Database

Alginate-diltiazem hydrochloride beads: optimization of formulation factors, in vitro and in vivo availability. 2003

A H El-Kamel, and O M N Al-Gohary, and E A Hosny

Department of Pharmaceutics, College of Pharmacy, King Saud University, PO Box 22452, Riyadh 11495. amalelkamel@yahoo.com

Alginate beads containing diltiazem hydrochloride (DTZ) were prepared by the ionotropic gelation method. The effects of various factors (alginate concentration, additives type, calcium chloride concentration and curing time) on the efficiency of drug loading were investigated. The formulation containing a mixture of 0.8% methylcellulose (MC) and 4% alginate cured in 2% calcium chloride for 6 h was chosen as the best formula regarding the loading efficiency. The release rate of DTZ from various beads formulations was investigated. The release of drug from alginate beads followed two mechanisms; by diffusion and relaxation of the polymer at pH 1.2, whilst diffusion and erosion are at pH 6.8. The in vitro release of DTZ from MC-alginate beads showed an extended release pattern which was compared with that from commercially available sustained-release (Dilzem SR) and fast release tablets (Dilzem). Thermal analysis revealed that the drug was molecularly dispersed in the beads matrix. Although the release characteristics of DTZ from Dilzem SR and MC-alginate beads were completely different, the bioavailability of DTZ in dogs was comparable as measured by AUC, MRT and relative bioavailability. The absolute bioavailability of MC-alginate beads and Dilzem SR was 88 and 93%, respectively.

UI	MeSH Term	Description	Entries
D008747	Methylcellulose	Methylester of cellulose. Methylcellulose is used as an emulsifying and suspending agent in cosmetics, pharmaceutics and the chemical industry. It is used therapeutically as a bulk laxative.	BFL,Celevac,Cellothyl,Cellulone,Citrucel,Cologel,Dacryolarmes,Methocel,Methyl Cellulose,Muciplasma,Cellulose, Methyl
D008863	Microspheres	Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers.	Latex Beads,Latex Particles,Latex Spheres,Microbeads,Bead, Latex,Beads, Latex,Latex Bead,Latex Particle,Latex Sphere,Microbead,Microsphere,Particle, Latex,Particles, Latex,Sphere, Latex,Spheres, Latex
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002122	Calcium Chloride	A salt used to replenish calcium levels, as an acid-producing diuretic, and as an antidote for magnesium poisoning.	Calcium Chloride Dihydrate,Calcium Chloride, Anhydrous
D002317	Cardiovascular Agents	Agents that affect the rate or intensity of cardiac contraction, blood vessel diameter, or blood volume.	Cardioactive Agent,Cardioactive Drug,Cardiovascular Agent,Cardiovascular Drug,Cardioactive Agents,Cardioactive Drugs,Cardiovascular Drugs,Agent, Cardioactive,Agent, Cardiovascular,Drug, Cardioactive,Drug, Cardiovascular
D003692	Delayed-Action Preparations	Dosage forms of a drug that act over a period of time by controlled-release processes or technology.	Controlled Release Formulation,Controlled-Release Formulation,Controlled-Release Preparation,Delayed-Action Preparation,Depot Preparation,Depot Preparations,Extended Release Formulation,Extended Release Preparation,Prolonged-Action Preparation,Prolonged-Action Preparations,Sustained Release Formulation,Sustained-Release Preparation,Sustained-Release Preparations,Timed-Release Preparation,Timed-Release Preparations,Controlled-Release Formulations,Controlled-Release Preparations,Extended Release Formulations,Extended Release Preparations,Slow Release Formulation,Sustained Release Formulations,Controlled Release Formulations,Controlled Release Preparation,Controlled Release Preparations,Delayed Action Preparation,Delayed Action Preparations,Formulation, Controlled Release,Formulations, Controlled Release,Prolonged Action Preparation,Release Formulation, Controlled,Release Formulations, Controlled,Sustained Release Preparation,Timed Release Preparation,Timed Release Preparations
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D004110	Diltiazem	A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on membrane functions.	Aldizem,CRD-401,Cardil,Cardizem,Dilacor,Dilacor XR,Dilren,Diltiazem Hydrochloride,Diltiazem Malate,Dilzem,Tiazac,CRD 401,CRD401
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004339	Drug Compounding	The preparation, mixing, and assembly of a drug. (From Remington, The Science and Practice of Pharmacy, 19th ed, p1814).	Drug Formulation,Drug Preparation,Drug Microencapsulation,Pharmaceutical Formulation,Compounding, Drug,Formulation, Drug,Formulation, Pharmaceutical,Microencapsulation, Drug,Preparation, Drug