Multifunctional Properties of Co-processed Dioscorea rotundata Starch and Abelmoschus esculentus Fruit Gum in Direct Compression of Metronidazole Tablets

Co-processing is a process that manipulates available excipients to produce better functional excipients. 

This study aims to prepare a co-processed excipient from starch extracted from Dioscorea rotundata (WYS) and gum extracted from pods of Abelmoschus esculentus fruit (OKG). 

The co-processed excipients (CYG) were prepared by co-fusing WYS and OKG at concentrations of 99:1, 97:3, 95:5 to produce CYG1, CYG3, and CYG5, respectively. Then, they were evaluated for their flow and swelling properties. Metronidazole tablets (MT1, MT3, and MT5) were prepared by direct compression. Similarly, tablets containing reference excipients of CombiLac® (MTC) and Prosolv® (MTP) were prepared. The tablets were evaluated for uniformity of weight, crushing strength, friability, disintegration time, and in vitro release. Fourier Transform Infra-Red (FTIR) was used to monitor the interaction between the excipients and metronidazole.

CYG1, CYG3, and CYG5 have good flow; their swelling profile was between 170% and 200%, more than WYS (80%). FTIR spectra showed no interaction between the excipients and metronidazole. The crushing strength-friability ratio was 42.03>39.65>25.63 for MT3, MT5, and MT1, respectively. MT5 had a longer disintegration time (63.87 s) than MT1 and MT3, which were similar to that of MTC; however, MTP had the longest disintegration time (111.50 s). The disintegration efficiency ratio showed that CYG1 and CYG3 have better disintegration properties than Prosolv®. All the co-processed excipients produced robust tablets comparable to those of CombiLac®.

CYG can be exploited as a multifunctional excipient in preparing oral tablet formulations.