Microencapsulation of Diclofenac Sodium into natural Lycopodium clavatum spores: In vitro release and gastro-ulcerogenic evaluations

Abstract

This study highlights the protective role developed by encapsulation of Diclofenac Sodium (DIC) into natural Lycopodium clavatum spores (LCS) to reduce gastric ulcerations associated with DIC administration in stomach of rats. Microencapsulation of DIC into empty LCS extracted from their natural, raw spore species was explored for the first time. LCS were characterized before and after drug loading using light microscopy, SEM, FTIR, TGA and particle size analyses. Different microencapsulation techniques (passive diffusion, vacuum-assisted and a combined passive-vacuum), varying loading duration and drug amounts were evaluated. Gastro-ulcerogenic activity of DIC loaded LCS against plain DIC was evaluated in rats. FTIR and TGA confirmed successful DIC encapsulation within the internal cavities of LCS. SEM, light micrographs and particle size analysis showed that drug loaded spores retained well defined microstructures similar to raw spores, with uniform size distributions of 20–25 μm. Encapsulation efficiency of DIC loaded LCS by vacuum-assisted loading was the highest (50%) compared to other loading techniques. A biphasic release pattern was achieved for drug loaded spores, with an initial fast release up till 2 h followed by a sustain release for 24 h, in phosphate buffer (pH 6.8), while ≥80% of plain DIC was released within 1 h. DIC loaded LCS showed substantial stomach protective action from related gastric ulcerations associated with DIC. Hence, a simple, reproducible approach utilizing Lycopodium clavatum spores as natural encapsulant for oral delivery was established, with uniform micro-size distribution.