**1. Introduction**

Tablets are the most preferred dosage form with respect to patient acceptability, flexibility in dose adjustment, easy manufacturing, and better stability [1, 2]. Irrespective of the nature of the drug and its manufacturing technique, tablets should meet some strict requirements in terms of mechanical strength,

disintegration, and drug release [3–5]. A variety of techniques are available for tablet preparation among which direct compression is mostly preferred due to simplicity, cost-effectiveness, and less number of involved steps [6, 7]. However it can be applied only to the powder blend having optimum rheological characteristics, mechanical strength, and disintegration behavior, i.e., the powder blend should flow efficiently, and the resultant tablet should have sufficient mechanical strength with acceptable disintegration behavior [8–10]. All these characteristics are interlinked, and usually improvement of one characteristic can adversely affect the other. Hit and trial is the mostly applied method for optimization of powder characteristics which is laborious and material consuming. Optimization of powder blend is carried out, mostly, in the last stage of formulation development (following pre-formulation studies). Usual reported time for formulation development is in the range of 14–20 days, which can further extend in certain cases. There was a need for a technique that can avoid the experimentation for optimization of powder characteristics and help in excipient selection, i.e., select proper quantity of an excipient with desired characteristics. SeDeM-ODT expert system is a preformulation tool and has solved most of the problems associated with material characterization at pre-formulation level. SeDeM-ODT expert system minimizes experimentation and facilitates the process of formulation development by helping in excipient selection (in terms of desired characteristics and required quantity).

**2.1 Parameters determined for characterization of powder material**

various parameters are grouped into six factors, as follows:

*DOI: http://dx.doi.org/10.5772/intechopen.92444*

*2.1.1 Dimension factor*

• Bulk density

• Tapped density

includes the following:

• Carr's index

the following:

• Cohesion index

• Hausner ratio

• Angle of repose

*2.1.4 Lubricity/stability factor*

• Flow ability

• Loss on drying

• Hygroscopicity

**169**

• Inter-particle porosity

*2.1.3 Flow ability/powder flow factor*

*2.1.2 Compressibility factor*

group are:

On the basis of physical characteristics and functionality of the ingredients,

*SeDeM-ODT Expert System: A Solution to Challenges in Characterization of Pharmaceutical…*

Parameters included in this factor affect the size of the tablet and its ability to pile up. Results of these parameters are also used in the mathematical calculation of other indices related to powder compressibility. Parameters included in this

The factor comprised of the parameters related to compressibility of powder and

This factor governs flow ability of the powder during compression and includes

Lubricity during compression and stability of the compressed tablets are affected by the parameters included in this factor. These are the following:

This incidence factor shows the rheological properties and stability of the powder and depends upon the intrinsic moisture and hygroscopicity of the material [14]. The low value of this incidence factor shows that the product will absorb moisture from the atmosphere, worsening its rheological properties (flow and compression) and consequently altering product stability. In case of values below

the acceptable limit, the following measures are taken:
