Development and evaluation of Pleurotus tuber-regium cornstarch composite as a direct compression multifunctional excipient

Aim: The aim was to develop a novel excipient from Pleurotus tuber-regium (PT)-cornstarch (CS) mixture and evaluate its multifunctional characteristics in tablet formulation. Materials and Methods: Composites were generated from dephytochemicalized PT and CS combined at 1:1 to 4:1 ratios and pregelatinized in a hot water bath at 65°C ± 2°C for 5 min. The paste was dried, pulverized, and screened through 150-µm sieve. PT-CS physical mixtures were prepared and their characteristics/functionalities in tableting chloroquine were compared to those of composites and microcrystalline cellulose (Avicel®). Results: PT ash value was 0.40 ± 0.09% and heavy metal contents were below official limits. PT’s differential scanning calorimetric (DSC) thermogram depicted broad melting peak at 329.5°C; this peak was attenuated by the presence of CS. Fourier transform infrared (FTIR) spectra predicted compatibility between PT and CS. Composites consolidated better and also flowed better than physical mixtures and Avicel®. Increasing PT content enhanced the excipients’ swellabilities, and composites possessed significantly (P < 0.05) better swelling indices than Avicel®. The composites underwent fragmentation before plastic deformation with yield pressures significantly (P < 0.05) higher than those of the physical mixtures, which exhibited only plastic deformation. The mechanical properties of chloroquine tablets were acceptable, with the 1:4 (PT:CS) imparting the best properties. Mean disintegration times for the commercial comparator and Avicel®-containing tablets were significantly higher (P < 0.05) than those of composites. Drug release from tablets formulated with composites were similar to the commercial comparator, but significantly higher (P < 0.05) than those of Avicel®. Conclusion: The novel composites are excellent multifunctional excipients, the best (PT:CS 1:4) one showcasing potentially better mechanical functionality than Avicel®, a popular multifunctional excipient.