Pharmaceutical Glass Composition Reducing Delamination and Viscosity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing borosilicate glasses used for pharmaceutical containers suffer from delamination issues, leading to the generation of insoluble foreign matter that can be harmful when administered to patients. Additionally, these glasses have high viscosity, making them difficult to process into complex shapes, and they lack sufficient hydrolytic resistance.
Innovation Solution
A glass composition for pharmaceutical containers is developed, with specific mol% ranges for SiO2, Al2O3, B2O3, Li2O+Na2O+K2O, MgO+CaO+SrO+BaO, and restricted molar ratios such as MgO/CaO, which has a working point of 1,270° C. or less. This composition enhances processability, reduces delamination risk, and improves hydrolytic resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If borosilicate glass containing large amount of B2O3 is used to satisfy the standard for components eluted from the glass, then hydrolytic resistance is improved, but delamination occurs causing generation of insoluble foreign matter
Solution Approach 1:
The patent changes the chemical composition parameters of the glass by reducing B2O3 content to 0.01-5 mol% and adjusting the ratio of MgO/CaO to 0.01-10, while maintaining SiO2 at 69-81 mol% and Al2O3 at 4-12 mol%. This parameter optimization resolves the contradiction by achieving both hydrolytic resistance and prevention of delamination through balanced composition control
Solution Approach 2:
The patent creates a composite glass system combining multiple oxides (SiO2, Al2O3, B2O3, Li2O, Na2O, K2O, MgO, CaO, SrO, BaO) in specific proportions to achieve a material that simultaneously provides hydrolytic resistance and eliminates delamination. The synergistic combination of these components creates a glass that avoids the harmful effects of conventional borosilicate glass
2Object-generated harmful factors
If aluminosilicate glass is used to reduce delamination by reducing B2O3 content, then delamination is suppressed, but viscosity increases making processability poor
Solution Approach 1:
The patent adjusts the glass composition parameters by controlling B2O3 at 0.01-5 mol% (lower than conventional aluminosilicate), Al2O3 at 4-12 mol%, and adding specific ratios of MgO/CaO (0.01-10) and alkali metals (Li2O+Na2O+K2O at 5-20 mol%). This parameter optimization reduces viscosity while maintaining low delamination, thereby improving processability
Solution Approach 2:
The patent applies different compositional characteristics to different aspects of the glass: low B2O3 and controlled Al2O3 for delamination prevention, while specific MgO/CaO ratios and alkali metal contents are optimized for viscosity control and processability. This localized optimization of different compositional elements resolves the contradiction
3Ease of manufacture
If processing temperature is increased to improve processability of high viscosity glass, then processability is improved, but components vaporize contaminating the inside surface
Solution Approach 1:
The patent modifies the glass composition to have lower viscosity by controlling B2O3 (0.01-5 mol%), Al2O3 (4-12 mol%), and adding MgO/CaO (0.01-10) and alkali metals (5-20 mol%). This allows processing at lower temperatures (working point ≤1270°C), preventing component vaporization and contamination while maintaining good processability
Data Source
AI summary
The present invention provides a glass for a pharmaceutical container, which includes as a glass composition, in terms of mol %, 69% to 81% of SiO2, 4% to 12% of Al2O3, 0% to 5% of B2O3, 5% to 20% of Li2O+Na2O+K2O, 0% to 12% of Li2O, 0% to 11% of Na2O, 0.01% to 11% of MgO+CaO+SrO+BaO, and 0.01% to 11% of CaO, which satisfies the following relationship: a molar ratio MgO/CaO<9.0, and which has a working point of 1,270° C. or less.