Purpose: A series of synthesized P(L)LA-PEG1.5kDa-P(L)LA copolymers with different poly-(L)lactide chains lengths have been evaluated as processing aid for the formulation of biodegradable particles through the CriticalMixTM process to load the model protein bovine serum albumin. Methods: Particles from Gas Saturated Solutions (PGSS) technique employs the plasticizing effect of supercritical carbon dioxide (scCO2) on polymers to generate particles, completely avoiding the use of organic solvents and using mild process conditions. The produced particles were characterized in terms of particle size, morphological aspect and drug loading capacity. Results: The introduction of the ABA triblock copolymers leads to the formulation of microparticles with size dependent by the length of the poly-(L)lactide chains. The increase of P(L)LA chains length to a value more than double of the PEG chain produced microparticles with a markedly higher average size and size distribution. Such triblocks blended into the PLA/PLGA formulation, increased the processability of the CriticalMixTM process. The carriers have been loaded with BSA, highlighting an efficient drug loading capacity (~ 75%) and protein stability. Conclusion: The presence of the ABA triblock copolymers increased the yield of the processed material and decreased the size of the particles together with an uniform distribution and porosity. These mild operating conditions ensure the retention of biological activity of the therapeutic peptides.
Use of block copolymers to produce biodegradable particles from gas saturated solutions (PGSS) process
PERINELLI, DIEGO ROMANO;CESPI, MARCO;BONACUCINA, Giulia;PALMIERI, Giovanni Filippo
2013-01-01
Abstract
Purpose: A series of synthesized P(L)LA-PEG1.5kDa-P(L)LA copolymers with different poly-(L)lactide chains lengths have been evaluated as processing aid for the formulation of biodegradable particles through the CriticalMixTM process to load the model protein bovine serum albumin. Methods: Particles from Gas Saturated Solutions (PGSS) technique employs the plasticizing effect of supercritical carbon dioxide (scCO2) on polymers to generate particles, completely avoiding the use of organic solvents and using mild process conditions. The produced particles were characterized in terms of particle size, morphological aspect and drug loading capacity. Results: The introduction of the ABA triblock copolymers leads to the formulation of microparticles with size dependent by the length of the poly-(L)lactide chains. The increase of P(L)LA chains length to a value more than double of the PEG chain produced microparticles with a markedly higher average size and size distribution. Such triblocks blended into the PLA/PLGA formulation, increased the processability of the CriticalMixTM process. The carriers have been loaded with BSA, highlighting an efficient drug loading capacity (~ 75%) and protein stability. Conclusion: The presence of the ABA triblock copolymers increased the yield of the processed material and decreased the size of the particles together with an uniform distribution and porosity. These mild operating conditions ensure the retention of biological activity of the therapeutic peptides.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
