Characterization of ceramic drug delivery devices: the effect of various temperature of incubation on the delivery of biologicals.

The objectives of this study are: (i) to determine the effect of temperature on the release rate of steroids and proteins from ceramic drug delivery devices (CDDD), and (ii) to examine the effect of polylactic acid (PLA) impregnation of tricalcium phosphate (TCP), and alumino-calcium-phosphorous oxide (ALCAP) ceramic capsules on the release of small and large molecular weight compounds, and (iii) to investigate the interaction of molecular weight and various incubation temperatures (25, 37 and 50 degrees C) on the rate of delivery from CDDD. The CDDD were prepared using standard laboratory protocols. Eight of 16 ALCAP and TCP ceramic capsules were impregnated with PLA and the remainder fabricated without PLA. Fourteen ceramic capsules were loaded with either 40 mg of testosterone or 40 mg of bovine serum albumin (BSA), and nothing was added to the two remaining capsules. All capsules were then sealed at both ends with Dow Corning Type A Silastic Medical Adhesive. Single capsules were suspended in serum bottles containing either 100 ml of 50% wt/vol aqueous ethanol solution (steroid-containing capsules) or 100 ml of phosphate buffered saline (pH 7.4) (protein-containing capsules). The bottles were then placed in one of three metabolic shaker baths that had been previously adjusted at 25, 37, or 50 degrees C and were oscillating at a frequency of 100 rpm. Testosterone release was measured spectrophotometrically at 245 nm and BSA by a colorimetric procedure.(ABSTRACT TRUNCATED AT 250 WORDS)