Related Experiment Video
Updated: Jan 21, 2026
The Effect of Interfacial Chemical Bonding in TiO2-SiO2 Composites on Their Photocatalytic NOx Abatement Performance
Published on: July 4, 2017
Minimum Interfacial Bonding Strength for Bilayer Tablets Determined Using a Survival Test
Shao-Yu Chang1, Changquan Calvin Sun2
1Pharmaceutical Materials Science and Engineering Laboratory, Department of Pharmaceutics, College of Pharmacy, University of Minnesota, 9-127B Weaver-Densford Hall, 308 Harvard Street S.E., Minneapolis, Minnesota, 55455, USA.
A minimum interfacial bonding strength (IBS) of 0.26 MPa is sufficient for bilayer tablets to withstand manufacturing and handling stresses. This IBS value ensures tablet integrity across various formulations and sizes, preventing quality issues.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
Background:
- Bilayer tablets offer advantages in drug delivery but are susceptible to interfacial delamination.
- Understanding the minimum interfacial bonding strength (IBS) is crucial for ensuring tablet integrity during processing and distribution.
Purpose of the Study:
- To determine the minimum interfacial bonding strength (IBS) necessary for bilayer tablets to withstand mechanical stresses.
- To establish a tentative criterion for adequate IBS in bilayer tablet formulations.
Main Methods:
- Bilayer tablets with varying IBS were fabricated and subjected to simulated manufacturing and handling stresses using a friabilator.
- Tablet integrity was assessed after repeated drops, and the minimum IBS required to maintain interface integrity after 1000 drops was identified.
Main Results:
- The required minimum IBS is influenced by layer composition and tablet size, with more brittle materials or larger tablets needing higher IBS.
- Incorporating HPMC into the formulation reduced the minimum IBS requirement.
- An IBS of 0.26 MPa was found to be sufficient for all tested bilayer tablet formulations and sizes to survive 1000 drops.
Conclusions:
- A minimum IBS of 0.26 MPa is proposed as a tentative standard for bilayer tablets.
- This criterion can help prevent quality defects related to insufficient interfacial bonding in pharmaceutical manufacturing.
Related Concept Videos
01:12Bonding and Strength of Aggregate
02:49Bond Energies and Bond Lengths
00:42Ionic Bonds
When atoms gain or lose electrons to achieve a more stable electron configuration they form ions. Ionic bonds are electrostatic attractions between ions with opposite charges. Ionic compounds are rigid and brittle when solid and may dissociate into their constituent ions in water. Covalent compounds, by contrast, remain intact unless a chemical reaction breaks them.
Opposing Charges Hold Ions Together in Ionic Compounds
Ionic bonds are reversible electrostatic interactions between ions...
03:05Acid Strength and Molecular Structure
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
02:45Valence Bond Theory
01:15Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations