Preformulation Studies and Development of a Herbal Tooth Powder Using Coconut Shell as a Natural Abrasive

Dentifrices are widely used oral-care preparations designed to clean teeth, remove dental plaque, and maintain oral hygiene. Tooth powders remain popular in several regions due to their simplicity, cost-effectiveness, and ease of formulation. Abrasives constitute a key component of dentifrices, as they assist in mechanical removal of stains and debris; however, excessive abrasivity may result in enamel damage, emphasizing the need for controlled and standardized abrasive materials [1,2]. Growing interest in herbal and natural oral-care products has encouraged the exploration of plant-based and naturally derived excipients. Herbal dentifrices are preferred due to their perceived safety, biocompatibility, and reduced side effects compared to synthetic formulations [3]. Concurrently, pharmaceutical research is increasingly focused on sustainable development through utilization of agricultural waste as functional excipients. Coconut shell is a lignocellulosic agricultural by-product generated in large quantities during coconut processing. Traditionally considered waste, coconut shell possesses hardness and structural properties that make it suitable for conversion into fine abrasive powder [4]. The present study aims to conduct systematic preformulation studies and develop a herbal tooth powder formulation using coconut shell powder as a natural abrasive [5,6,7].

MATERIALS AND METHODS

MATERIALS

1. Coconut Shell Waste (Cocos nucifera L.)

– Collected from local coconut-processing vendors and fruit markets.

– Mature, dry shells selected for uniform hardness.

2. Herbal Ingredients (for dentifrice formulation)

Tulsi powder, Beetroot Powder, Ritha powder, Amla powder, Salt

3. Chemical Reagents

Distilled water, Hydrochloric acid (0.1 N), Sodium hydroxide (0.1 N), Ethanol, Reagents for limit test of arsenic & lead, Chemicals for moisture analysis

1. 2. Instruments and Equipment

Mechanical grinder & pulverizer, Sieve set (44#, 60#, 72#, 80#), Hot air oven, Moisture analyser, Analytical balance, Glassware: measuring cylinders, funnels, beakers, spatulas, jars will be required for this project.

METHODOLOGY OVERVIEW

2.3.1 Procurement of Coconut Shell Waste

• Coconut shell waste was collected from local fruit markets.
• Defective, fungal-infected, or immature shells were discarded.
• Shells were washed with water to remove dust and sun dried.

2.3.2 Reduction of Particle Size [8,9]

• Dried shells were crushed to coarse powder.
• Coarse pieces were ground using a mechanical grinder.
• Powder was sieved using mesh numbers #44, #60, #72, and #80.
• Four batches were prepared based on mesh size.

2.3.3 Pre-Formulation Studies

2.3.1 General Appearance: Physical examination like colour, odour, taste was done by organoleptic inspection.

2.3.2. Angle of Repose: Angle of repose was measured by fixed funnel method. The fixed funnel method uses a funnel being secured with its tip at a given height h above the graph paper which was placed on a flat horizontal surface, granules were carefully transferred through the funnel until the apex of the conical pile touching the tip of the funnel10,11].

???????????? ?=?????

Where ? = angle of repose

r = radius of the base of conical pile and

h= height of pile

Observation: Batch C (#72/#80 range) exhibited balanced flow and abrasivity, selected for formulation.