Fabrication and Characterization of Electrospun Nanofibers for the Modified Release of the Chronobiotic Hormone Melatonin

OBJECTIVE

Aiming at the modified release of melatonin (MLT), electrospun-MLT loaded nanofibers, filled into hard gelatin and DRcapsTM capsules, were used as formulants.

METHODS

Cellulose acetate, polyvinylpyrrolidinone and hydroxypropylmethylcellusose (HPMC 2910) were used for the preparation of the fiber matrices through electrospinning. The in vitro modified release profile of MLT from the fabricated matrices in gastrointestinal-like fluids was studied. At pH 1.2, the formulations CA1, CA2, PV1, HP1, HP2 and the composite formulations CAPV1-CAPV5 in hard gelatin capsules exhibited fast MLT release.

RESULTS

In general, the same trend was observed at pH 6.8, with the exception of CAPV1 and CAPV2. These two composite formulations delivered 52.08% and 75.25% MLT, respectively at a slower pace (6 h) when encapsulated in DRcapsTM capsules. In all other cases, the release of MLT from DRcapsTM capsules filled with the MLT-loaded nanofibers reached 100% at 6h.

CONCLUSION

These findings suggest that the MLT-loaded nanofibrous mats developed in this study exhibit a promising profile for treating sleep dysfunctions.

Modified In Vitro Release of Melatonin Loaded in Nanofibrous Electrospun Mats Incorporated Into Monolayered and Three-Layered Tablets

Modified release tablet formulations with melatonin (MLT) are clinically more useful in initiating and maintaining sleep in elderly insomniacs, compared with those designed for immediate release. Aiming at the modified release of MLT, monolayered and 3-layered tablets, incorporating nanofibrous mats composed of cellulose acetate and polyvinylpyrrolidone loaded with MLT, were prepared and studied. In vitro dissolution profiles of MLT in gastrointestinal-like fluids revealed tableting pressure/pH-dependence. The release of the hormone from physical mixture tablets was generally slower from the nanofibers-based tablets, thus exhibiting in the latter case properties that are necessary for the control of both the sleep-onset and the maintenance dysfunctions. The nature of the excipients (hydroxypropylmethylcellulose or lactose monohydrate) used in this study to produce 3-layered tablets was also found to affect the release of MLT, adjusting it to the endogenous hormone's chronobiotic profile. The release of MLT from formulation F(nf)₂ (nanofiber mats incorporated into 3-layered tablets containing lactose monohydrate both in the upper and lower layers) was found to be in closer alignment with these effects than the other delivery systems.