# Tablet Scoring: Current Practice, Fundamentals, and Knowledge Gaps
## 3 Oral Solid Dosages: Tablets  
Oral solid tablet formulations remain the preferred route of administration [60]. Oral solid dosage form drugs: (1) are less complex to formulate, (2) in general, they provide better chemical stability, and (3) are the most preferred across diverse patient populations. About one-half of all prescriptions dispensed for adolescents and adults are for tablets [60].  
Upon administration, a tablet begins absorption in the gastro intestinal (GI) tract (in the lining of the mouth in some cases). Following absorption, the drug is metabolized in the liver, then enters the bloodstream. The liver can greatly affect the potency of the tablet. Other important factors that can influence absorption include: age, weight, gender, race, mental and physical conditions, compatibility with co-administered medications, contents of stomach and pH level in the stomach. The pH level in the stomach is important as it varies at fed and fasted conditions [60; 61; 62; 63].  
Tablets are available in different shapes, forms, or sizes depending on the dose [64]. The size and shape of the tablets are typically decided by the company's marketing group [65; 66].  
The complexity of tablet formulation and manufacturing is dependent of the biopharmaceutical properties of the drug substance. The biopharmaceutical property correlates with the variation in drug concentration with time as a result of absorption, distribution and elimination [60; 61; 62; 63]. In such case, the release profile of the drug is dependent on: drug dose, administration route, rate and extent of absorption, distribution rate, rate of elimination, and the minimum effective concentration [67; 68; 69].  
Figure 1 shows the evolution of the plasma drug concentration over time after dose administration. The dotted horizontal lines show the minimum effective concentration (MEC) and the maximum safe concentration (MSC) [70]. A therapy is efficacious during the times when there is enough drug exposure in the plasma with a concentration that is above the MEC level. However, the drug exposure in the plasma should never exceed the MSC level [71].  
The biopharmaceutical properties and the physical chemistry of a drug substance play an important role in designing its formulation [19; 72]. The drug substance can exist as a stable crystalline form, a metastable crystalline form or an amorphous form. It is important that the polymorph does not change during the formulation development process [73; 74]. In general, drug substances without excipients are typically used in the proof of concept phase or for pharmacokinetic studies in animal models [75]. Tablets may differ greatly in size and weight depending on the intended dose and the method of administration [76]. In order to facilitate the ease of administration, several types of alteration to the final dosage form are implemented. Some of the practices involve tablet splitting/tablet scoring [77; 78].  
Figure 1: Drug concentration profile in plasma over time.  
Tablet splitting or tablet scoring is the practice of partitioning a tablet in order to obtain a lower dose or multiple smaller doses; this is done either to reduce cost or because the commercially available tablets contain a larger dose than is required.