Table 3.

Postcompressing tests of ODTs.

Parameters	Properties	Purpose and considerations		Ref.
Weight variation	The weight of 20 randomly chosen tablets is determined then the mean weight is calculated	Weight average (mg)	Max SD.	[77]
		130 or <130	10
		130-324	7.5
		324 or >324	5
Content-uniformity	3 tablets of each formulation were powdered and then the UV absorbance of mixture equivalent to 1 mg of API is measured	If the API is less than 25 mg, the content-uniformity test is used. Otherwise, the weight-variation test is applicable		[78, 79]
Hardness	By using a Varian tablet hardness tester crushing strengths of six randomly selected tablets were measured and expressed in Newton units	It shows the mechanical integrity of tablets		[73, 77]
Porosity	It is measured by a mercury porosimeter	Porosity moderately shows the amount of water penetration to formulation and disintegration time		[61]
Thickness and diameter	Diameter and thickness of ten randomly selected tablets were measured by putting between the arms of the digital Vernier caliper and recorded as average diameter and thickness	—		[68, 73]
Friability	Some tablets are weighed (initial weight) before putting them into the friabilator (at 25 rpm and 4 min), then after weight loss measurement, the friability value is calculated	According to USP 24: % friability value should be <1		[79]
Wetting time/water absorption ratio	10 mL of eosin solution is poured into a dish and weight of tablets before placing in the dish and after reaching the eosin to the upper part of them is measured	Short wetting time leads to fast disintegration		[68]
Moisture uptake	10 tablets are put in a desiccator (37°C, 1 d), then tablets are weighed and exposed to 75% RH (25°C, 15d) and increase in weight is recorded	Used to evaluate the stability of the formulations		[80]

RH: relative humidity.