*2.1.1 Dimension factor*

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

quantity).

following:

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**2. SeDeM-ODT expert system**

*Advanced Functional Materials*

SeDeM-ODT expert system.

SeDeM-ODT expert system.

and robust processing by direct compression technology.

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

SeDeM-ODT expert system is novel pre-formulation technique applied for development of a solid dosage form (tablets) by direct compression technology [11]. The system characterizes powder substance on the basis of various parameters related to flow, compressibility, and disintegration behavior. Physical profile of powder substance is developed, suggesting its suitability for direct compression and bucco-dispersibility [12, 13]. SeDeM expert system can be segmented into the

**SeDeM expert system:** It determines suitability of the powder substance for

**SeDeM-ODT expert system:** It is the newest version of SeDeM expert system and characterizes the powder substances with respect to rheological characteristics, compressibility, and disintegration behavior, simultaneously [14]. Three extra parameters related to characterization of disintegration behavior are included in the

The SeDeM-ODT expert system has been introduced with the aim of designing oro-dispersible tablets (ODTs) by direct compression [14]. This system is unique as it provides an oro-dispersible tablet formulation by direct compression, i.e., it links prediction of suitability of powder for direct compression and rapid disintegration of the tablets. SeDeM-ODT expert system is used for evaluation of critical quality attributes of powder substance, having an impact on the final product. Quality by Design guidelines ICH-Q8 [15] provides the basis for

SeDeM-ODT expert system also calculates the amount of excipients with certain characteristic required for the correction of a particular property in order to make a final blend suitable for direct compression [14]. Several parameters have been selected that must be fulfilled by the formulation (excipients) to ensure successful

direct compression only [11, 13]. That is, the system characterizes powder substance with respect to its rheological characteristics and compressibility.

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 group are:

