Efficacy and tolerability of a new formulation of sodium phosphate tablets (INKP-101), and a reduced sodium phosphate dose, in colon cleansing: a single-center open-label pilot trial

Background: The tablet form of sodium phosphate for bowel preparation for colonoscopy contains microcrystalline cellulose. This inactive ingredient produces a residue that obscures mucosal visualization and is time-consuming to remove during colonoscopy.

Aim: To perform an open-label study of efficacy and tolerability of a modified formulation with microcrystalline cellulose reduced by 50% (code named INKP-101) and a lower total dose of sodium phosphate.

Methods: Patients scheduled for colonoscopy self-administered 28 INKP-101 tablets (42 g sodium phosphate). Colon cleansing efficacy was evaluated using a standard 4-point scoring system and the amount of microcrystalline cellulose present and time spent removing it using an 8-point scale.

Results: A total of 31 patients were screened and enrolled. Thirty patients had a colonoscopy and were evaluated for colon cleansing efficacy. Overall colon cleansing was rated as excellent and good in 90% and 10% of patients respectively. About 77% of patients had microcrystalline cellulose scores of 2 or 3 (corresponding to <1 or 1-2 min spent removing microcrystalline cellulose, respectively). The drug was well-tolerated and adverse events were generally benign.

Conclusion: A new formulation of sodium phosphate with reduced microcrystalline cellulose and a lower total dose of sodium phosphate was effective for colonoscopy and well-tolerated.