Electrospun organic-inorganic nanohybrids as sustained release drug delivery systems

In this work, the non-steroidal anti-inflammatory drugs ibuprofen (ibu) and ketoprofen (ket), both poorly soluble in water, were first intercalated into layered double hydroxide (LDH) nanoparticles. The drug-LDH composites were then mixed with poly(ε-caprolactone) (PCL) at 5% and 10% w/w ratios and processed into fibers via electrospinning, yielding organic-inorganic nanohybrids. PCL/drug fibers were additionally prepared as controls. The average diameter of the fibers ranged from 400 to 1000 nm. The fibers are found to be smooth and cylindrical, with the LDH-containing systems having more homogenous fibers than those without the inorganic filler. From in vitro drug release tests, it was determined that more than 90% of the intercalated ibu and ket were released from the drug-LDH nanohybrids within the first 4 hours. Similarly, more than 60% of the incorporated drug was freed from the PCL/drug fibers in this time period. However, the release rates of both ibu and ket from the drug-LDH loaded PCL fibers were significantly slower. Only 44-48% of ibu was released from the PCL/ibu-LDH system after 5 days, while the amount released in the case of ket was 20-25%. In addition, drug release was still ongoing after 5 days for all the PCL/drug-LDH samples. These systems are thus proposed to have potential as implantable drug delivery systems.