Controlled drug release applications of carotenoid loaded polycaprolactone particles

The polymers have wide range of application area including drug delivery systems. Polymeric materials can be used for encapsulation of some organic or inorganic materials to increase some properties of encapsulated material such as pH resistance, heat resistance or to decrease some undesired situations like oxidation. The use of ultrasound in the extraction of some natural active materials such as lycopene which has antioxidant properties is growing rapidly because of a decrease in the necessity of heat. The tomato, as a vegetable, becomes an important source for lycopene (C40H56). .In this study, dried tomato powder (TP) was used as a source of lycopene and the lycopene was extracted using two different methods, ultrasound assisted extraction (UAE) and conventional solvent extraction (COSE). In the extraction experiments, the mixture of hexane:acetone:ethanol was used as a solvent mixture by (2:1:1) volume ratio and Poly(-capsrolactone) (PCL) as polymeric material to encapsulate the lycopene. To optimize the extraction processes response surface methodology was used.The maximum extraction yields (mg lycopene/kg tomato powder) were observed at 1:56 solid/liquid ratio using the conditions as 166 W for 26 min and 45C for 50 min, for UAE and COSE methods, respectively. The results indicated that the same lcypone extraction yield is reached in the UAE method than the COSE one. The antioxidant activity of tomato powder was measured using the ABTS colorimetric method. The antioxidant capacity of the extract obtained using the UAE was found as 12.48 mg Trolox/g tomato powder whereas the extract obtained using the COSE was found to be 11.08 mg Trolox/g tomato powder. Although the lycopene contents in the extracts obtained by the both UAE and COSE techniques are the same, the extract obtained from UAE technique, indicated a higher antioxidant activity than that from COSE. The nanoparticle formulations prepared by nanoprecipitation method contain nanoparticles in which lycopene exists as an active ingredient and polycaprolactone (PCL), as a polymer. Acetone is used as the solvent and Span®80 and Tween®80, as non-ionic surfactants which are known as good dispersion agents. Polymeric structure entrapped the active material and protects from hydrolytic and enzymatic degradation in the gastrointestinal tract. In addition, controlled release process will prolonge ilycopene life in blood stream and will increase its therapeutic effect. Lycopene loaded PCL nanoparticles were successfully prepared in the range of 133-172 nm particle size. The SEM analysis showed that the nanoparticles have a spherical shape. Polydispersity index (PDI) of the particles smaller than 0.2, can be evaluated as an indication of the homogeneity of nanoparticles synthesized. The encaspulation efficiencies of the loaded nanoparticles varied between 78-90 %. In-vitro lycopene release experiments were showed that the nanoparticles have initial burst release varied between 23-36% during the first 2 hours. Total release of formulations was changed between 64-93% in 24 hours. Nanosuspensions incluiding the lycopene loaded PCL nanoparticles showed a good stabilityin the dark at 4 C and 25 C (at room temperature) for 40 days.