A Biodegradable Copolyester, Poly(butylene succinate-<i>co</i>-ε-caprolactone), as a High Efficiency Matrix Former for Controlled Release of Drugs

• Main Authors: Eduardo Galdón (Author), Mónica Millán-Jiménez (Author), Gloria Mora-Castaño (Author), Antxon Martínez de Ilarduya (Author), Isidoro Caraballo (Author)
• Format: Book
• Published: MDPI AG, 2021-07-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/pharmaceutics13071057; 1999-4923
• Keywords: poly(butylene succinate-<i>co</i>-ε-caprolactone); biodegradable polymer; ultrasound-assisted compression; hot melt extrusion; controlled release; nanostructured matrices; Pharmacy and materia medica; RS1-441
• Source: Pharmaceutics, Vol 13, Iss 7, p 1057 (2021)

A biodegradable copolyester, poly(butylene succinate-<i>co</i>-ε-caprolactone) (PBS_CL), was used for first time as an excipient for pharmaceutical dosage forms using direct compression and hot processing techniques (ultrasound-assisted compression (USAC) and hot melt extrusion (HME)). Robust binary systems were achieved with hot processing techniques, allowing a controlled release of the drug. With only 12% <i>v</i>/<i>v</i> of PBS_CL, controlled release forms were obtained using USAC whereas in HME over 34% <i>v</i>/<i>v</i> of excipient is necessary. Amounts over 23% <i>v</i>/<i>v</i> allowed a long-extended release for more than 72 h following diffusional kinetic. Thanks to the high melting point of theophylline and the physicochemical properties of PBS_CL selected and synthesized, the structure of the excipient inside the USAC tablets and HME filaments corresponds to a continuum medium. A percolation threshold around 23% <i>v</i>/<i>v</i> was estimated, which agrees with a continuum percolation model. The polymer shows a high excipient efficiency value using HME and USAC. A nanostructured matrix with wall thicknesses lower than 0.1 µm was obtained. This leads to a very effective coating of the drug particles by the excipient, providing a slow and reproducible release. The present study therefore supports the use of PBS_CL, for the preparation of controlled release dosage forms using hot processing techniques.