Accession Number : ADA130839

Title :   Local Anesthetic Microcapsules.

Descriptive Note : Annual rept. 1 Jul 80-30 Mar 81,

Corporate Author : BIOTEK INC WOBURN MA

Personal Author(s) : Williams,David L ; Kerrigan,James H ; Nucefora,William A

PDF Url : ADA130839

Report Date : 15 Apr 1981

Pagination or Media Count : 42

Abstract : Three kilograms of poly-L(-)lactide has been synthesized for this contract and for Contract No. DAMD 17-80-C-0093. This polymer has a viscosity (R.S.V.) of 1.19 dl/g, a molecular weight (MWw) of 45,700 and a polydispersity of 2.14. Materials from a previous contract was used for preliminary experiments. Both lidocaine (HC1) and etidocaine (HC1) have been successfully micro-encapsulated using the Wurster coating process. Samples were taken at 10, 20, 30, 40, and 50% polymer loading (60% also for etidocaine). These samples were sieved and various size fractions were analyzed for drug release. Large microcapsules containing 50% lidocaine are required to delivery drug in vitro at the target rate (e.g. 150-212 micrometer deliver 36% in 1 hour, 54% in 2 hours, 72% in 4 hours, and 82% in 6 hours). Etidocaine microcapsules deliver 17% in 1 hour, 24% in 2 hours, 39% in 4 hours, and 48% in 6 hours). Appropriate samples are being stored for stability testing. Microcapsules from a previous program were used to develop animal model studies. Both lidocaine and etidocaine an be measured in blood by gas chromatography. Tactile response was measured after subcutaneous implantation of lidocaine crystals (neat) and microcapsules.

Descriptors :   *Local anesthetics, Encapsulation, Polymers, Synthesis(Chemistry), Release, Stability, Storage, In vitro analysis, In vivo analysis, Blood circulation, Implantation, Subcutaneous tissue

Subject Categories : Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE