Isolation and Characterisation of Starch from Tiger Nut (Cyperus esculentus) Cultivated in Kogi State as a Pharmaceutical Excipient

Tiger nut (Cyperus esculentus) is a tuber crop cultivated across North Central Nigeria, with Kogi State representing a significant production area. Its starch has recently attracted interest as a natural pharmaceutical excipient due to the crop's local availability and renewability. This study isolated starch from tiger nuts obtained from Okene and Lokoja markets in Kogi State and evaluated its physicochemical properties for pharmaceutical excipient use. Starch was extracted by alkaline steeping, wet milling, and centrifugal sedimentation. Characterisation encompassed moisture content, pH, swelling power, solubility, gelatinisation temperature, particle size, and flow properties including angle of repose and Carr's index. The isolated starch was evaluated as a disintegrant in paracetamol tablets at concentrations of 5%, 10%, and 15% w/w in comparison with sodium starch glycolate at equivalent levels. Starch yield was 24.3% on dry weight basis. Flow properties were in the passable range, with angle of repose of 38 degrees and Carr's index of 19.4%. Swelling power at 80 degrees Celsius was 12.7 g/g, indicating good water uptake capacity. Tiger nut starch at 10% produced disintegration times of 4.8 minutes, within pharmacopoeial limits and comparable to sodium starch glycolate at 5%. These results indicate that Kogi State tiger nut starch possesses acceptable physicochemical properties for pharmaceutical application as a disintegrant. Keywords: tiger nut starch, Cyperus esculentus, pharmaceutical excipient, disintegrant, Kogi State.