title: The role of density on the release profiles of hydrophobic and hydrophilic compounds from TCPL delivery systems.
abstract: Several studies have shown that tri-calcium phosphate lysine drug delivery systems (TCPL) are capable of releasing various organic compounds at a sustained manner for long duration. The fabrication of TCPL devices is complex and the manipulation of various factors can alter drug release profiles. The compression of the TCPL material into the capsular form is an instrumental factor when studying the desired release profile. The objectives of this investigation were: 1) to study the interrelationship between the release profiles of devices that had been cold pressed at two different densities (1.53 +/- 0.15 (Low density, TCPL-LD) and 1.98 +/- 0.7 gm/cm3 (High density, TCPL-HD)), and 2) to evaluate the role of the change in density that might have on the release of hydrophobic and hydrophilic compounds in an in vitro environment. A total of 16 serum bottles were used and later subdivided into four groups (n = 4). Groups I and II contained TCPL-HD and TCPL-LD capsules each loaded with 20 mg of progesterone (P). Groups III & IV contained TCPL-HD and TCPL-LD capsules that were loaded with 20 mg of Bovine Serum Albumin (BSA). Each serum bottle in groups III and IV was filled with 100 mL of phosphate buffer saline (pH 7.4) and 10 microL of sodium azide (antibacterial agent). Serum bottles in groups I and II were filled with 50% alcohol (wt/vol). Samples were withdrawn at various time intervals and the release profiles were analyzed by using standard spectrophotometer techniques. Data analysis was conducted by using Jandel Sigma Stat Statistical software. Results of this investigation suggest that: 1) TCPL-HD and TCPL-LD devices were capable of releasing P and BSA at sustained levels, 2) regardless of the loaded drugs, the release profiles from TCPL-LD devices was found to be significantly higher (p < 0.05) than the release profiles of P and BSA from TCPL-HD, and 3) physiochemical characteristics of the drug to be delivered are instrumental in regulating the rate of release and duration or availability of an effective and safe dose (BSA > P).
authors.affiliation: Naval Research Program, Jackson State University, MS 39204, USA.
authors.forename: K
authors.initials: K
authors.lastname: Byrd
authors.forename: H
authors.initials: H
authors.lastname: Benghuzzi
mesh_terms: D002130:Calcium Phosphates; D002516:Ceramics; D016503:Drug Delivery Systems; D008239:Lysine; D008970:Molecular Weight; D010710:Phosphates; D011374:Progesterone / Q000493:pharmacokinetics*; D012710:Serum Albumin, Bovine / Q000493:pharmacokinetics*
chemical_list: D002130:Calcium Phosphates; D010710:Phosphates; C112656:tricalcium phosphate lysine; D012710:Serum Albumin, Bovine; D011374:Progesterone; D008239:Lysine