Effects Of Polylactic Acid Coating and Compression Load on the Delivery of Protein and Steroid from HA Ceramic Devices.

Density variations, due to particle size and time and temperature of sintering, affect the delivery profile of substances from ceramic delivery devices. This investigation was conducted to study the effect of polylactic acid (PLA) impregnation on the porosity of hydroxyapatite (HA) capsules by studying the delivery rate of bovine serum albumin (BSA) and testosterone (TE). HA capsules were fabricated by cold compressing calcined particles at 1000, 3000, and 5000 lbs. Each group was subdivided into PLA-impregnated and non-PLA impregnated capsules. Each capsule was loaded with either 40 mg of TE (impregnated or nonimpregnated with PLA polymer) or BSA. Data obtained in this study suggest that: (1) PLA impregnation of HA ceramic capsules decreases the rate of release of drugs from the ceramic reservoir, (2) Physiochemical characteristics of the drugs to be delivered is an instrumental key in the sustained release profiles, (3) Compression load of HA reservoirs is a key factor in predicting the duration and level of sustained delivery, and (4) Polymer coating of HA ceramic capsules reduces the pore size, as well as, blocking some of the pores on the surface.