Cutter mill

Cutter Mill

The cutter mill (Fig. 1) is very similar to the hammer mill in operation, except that sharp blades are used in place of blunt surfaces. Hammer and cutter mills are especially suited for brittle or fibrous materials and can be considered the most commonly encountered mills for roller compaction (in dry granulation). Construction and Working […]

Pin mill

Pin Mill

Pin mill is a method of comminution that acts by producing particle impact and attrition. Particle size reduction occurs by impaction with the pins and by attrition between pins as the particles travel outwards under the influence of centrifugal force. Construction and Working of Pin Mill Pin mills consist of two horizontal steel plates with […]

Fluid Energy Mill

  Fluid energy mill, also known as jet mill or micronizing, is a size reduction method that operates through particle impaction and attrition. Figure 1 illustrates a form of a fluid energy mill. Both circular and oval-path designs are available for this type of milling. Construction and working of Fluid Energy Mill In the fluid-energy […]

Hammer mill

Hammer Mill

A hammer mill carries out size reduction by using impact. Hammer mills consist of a series of four or more hammers hinged on a central shaft which is enclosed within a rigid metal case (fig.1). The material is fed at the top or center, thrown out centrifugally, and ground by the impact of the hammers […]

Ball mill in operation showing correct cascade action.

Ball Mill

A ball mill is an example of a comminution method which produces size reduction by both impact and attrition of particles. The ball mill consists of a horizontally rotating hollow vessel of cylindrical shape with the length slightly greater than its diameter. The mill is partially filled with balls of steel or pebbles, which act […]

Mechanisms of Comminution


Comminution, or size reduction, is the operation carried out for reducing the size of bigger particles into smaller ones of the desired size and shape with the help of external forces. Moreover, the function of size reduction may be to aid efficient processing of solid particles. Additionally, it facilitates powder mixing or the production of […]

The polymeric structure of sodium starch glycolate.

Sodium Starch Glycolate

Starch is a generic term for carbohydrate particles found in many plants. Starch grains swell in contact with water, and this appears to be an important property that relates to their use as tablet disintegrants. Sodium starch glycolate is the sodium salt of cross-linked carboxymethylated starch (chemically modified starches). When viewed under the microscope it […]

Polymeric structure of Cellulose acetate phthalate

Enteric Coated Tablets

Enteric coated tablets, also called gastro-resistant tablets, have delayed-release features. They are designed to pass unchanged through the stomach to the intestines, where the tablets are insoluble at the low pH of the stomach but dissolve at the higher pH values of the intestine. Some of the most important reasons for enteric coating are: To […]

Fig. 1: The chemical structure of cellulose.

Microcrystalline Cellulose

Microcrystalline cellulose (MCC), often known as Avicel, is the most common of cellulose (Fig.1) powder used in tablet formulation. It exists in two grades, pH 101 (powder) and pH 102 (granules), and possesses good flow properties with excellent direct compression characteristics. Microcrystalline cellulose is insoluble in water and alcohol. Despite being insoluble in water, promotes […]

Film coated tablet production

Film Coated Tablet

A film coated tablet is a type of oral medication where the tablet’s surface is covered with a thin layer of a polymer or similar material. This coating serves several purposes, including masking the taste of the medication, protecting the tablet from moisture, and making it easier to swallow. Types of film coating The common way […]