S-adenosyl-l-methionine (SAMe)-loaded nanochitosan particles: synthesis,characterisation and in vitro drug release studies

Chitosan-based drug carriers are being widely exploited for sustained and targeted delivery in cancer, anti-depression and nutritive therapeutics. In this paper, we report the preparation of S-adenosyl-l-methionine (SAMe) drug-loaded nanochitosan-based tablets and the sustained delivery of the drug substance in simulated intestinal conditions through an in vitro study. The convertibility of high molecular weight commercial chitosan to nanoparticles by ionic gelation using potassium pyrophosphate was achieved without employing harsh reaction conditions through an intermediate water-soluble chitosan preparation. The prepared nanochitosan particles with an average size of 85–127 nm showed good drug-loading capacity. In vitro release studies showed a continuous and slow release of the drug over 14 hours. Different kinetics models were applied to drug release data in order to evaluate the releasing mechanism. The drug release data fit well into the Higuchi expression, suggesting a diffusion-controlled drug delivery. The diffusional coefficient of 1.83 indicated that the drug release from the chitosan matrix was through swelling of the matrix. Agreement of the kinetic data with Higuchi and Korsmeyer–Peppas models have led us to conclude that the delivery of the SAMe drug from the nanochitosan drug carrier took place by the diffusion-controlled swelling mechanism described as Super case II transport. The prepared nanochitosan matrix was also found to be an environment-sensitive vehicle suitable for controlled drug delivery.