Development and Characterisation of an Optimised Toothpaste of Achyranthes aspera plant extract for the Effective Protection from Dental Black Stain forming Chromogenic bacteria species

The dental black stain (BS) is formed due to the colonisation of chromogenic bacteria, which is commonly reported in the population at the pre-puberty age. The currently available methods for black stain prevention such as dental scaling, scraping and use of chemicals etc. are reported with several drawbacks. The flavonoids and other phytochemicals found in the plant Achyranthes aspera are reported with effective antibacterial activity against chromogenic bacteria. Hence, the investigation aimed to formulate a herbal toothpaste containing the Achyranthes aspera plant to prevent black stain formation in children. The minimum inhibitory concentration (MIC) of the plant extract was determined against the Streptococcus mutans and Enterobacter ludwigi. The face centered central composite (3²) design was employed to optimise the formulation. Thirteen trial batches were formulated by varying the concentration of calcium carbonate (CaCO₃) (30%-50%w/w) and glycerin (20%-30%v/v). A combination of CaCO3 and glycerin at 30:30%w/w were selected as the optimised formulation and subjected to in vitro antibacterial study. No statistically significant difference between the developed toothpaste and chlorhexidine mouthwash was reported in the in vitro antibacterial activity. The stability profile of the optimized formulation was found to be satisfactory. The developed toothpaste containing Achyranthes aspera extract may be suitable for regular use and may prevent the formation of black stains in the pediatric population.