Soft Capsule Coating pH Adjustment for Statin Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pharmaceutical preparations containing ω3 polyunsaturated fatty acids (ω3PUFAs) and statin compounds face stability issues during manufacture, distribution, and storage due to the instability of statin compounds and gelatin capsule coatings, particularly for water-soluble statins, leading to decomposition and insolubilization.
Innovation Solution
A soft capsule formulation with a gelatin coating adjusted to a pH of 7.0 to 9.5, incorporating carbonates, metasilicate aluminate, or phosphate as buffers, and adding succinylated gelatin, organic acids like tartaric acid, or hydrolyzed gelatin to prevent statin decomposition and gelatin coating modification, while using hydroxypropyl methylcellulose (HPMC) on the inner surface for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If statin compounds and ω3PUFAs are combined in a soft capsule preparation, then pharmacodynamic synergism and patient compliance are improved, but stability during manufacture, distribution, and storage deteriorates due to decomposition of statin and insolubilization of gelatin coating
Solution Approach 1:
A water-soluble polymer film (HPMC) is introduced as an intermediary layer between the statin compound and the gelatin coating. This film prevents direct contact between the statin and gelatin, thereby preventing the statin from causing insolubilization of the gelatin coating while maintaining the stability of both components during storage and manufacture
Solution Approach 2:
The pH of the gelatin coating is adjusted to alkaline conditions (pH 7.0-9.5) using buffers such as carbonates, metasilicate aluminate, or phosphate. This parameter change stabilizes the statin compound by preventing acid-catalyzed decomposition and lactonization, while the water-soluble polymer film ensures the coating remains soluble
2Ease of manufacture
If gelatin capsule coating is used for soft capsule preparation, then ease of manufacture and patient acceptance are improved, but stability deteriorates due to insolubilization and modification of the coating during storage
Solution Approach 1:
A water-soluble polymer film (HPMC) is applied to the inner surface of the gelatin coating to act as a protective intermediary. This film prevents the gelatin from undergoing insolubilization reactions while maintaining the ease of capsule manufacture and the familiar gelatin-based coating structure
Solution Approach 2:
The capsule coating is transformed into a composite structure consisting of gelatin as the base material and a water-soluble polymer (HPMC) film as the protective layer. This composite structure combines the manufacturing advantages of gelatin with the stability benefits of the water-soluble polymer
3Reliability
If pH is adjusted to alkaline conditions to stabilize statin compound, then decomposition is prevented, but gelatin coating insolubilization is promoted
Solution Approach 1:
A water-soluble polymer film (HPMC) is introduced as an intermediary barrier between the alkaline gelatin coating and the gelatin matrix. This film allows the pH to be maintained at alkaline levels for statin stability while preventing the alkaline conditions from causing gelatin insolubilization
Solution Approach 2:
The pH of the gelatin coating is precisely controlled to the range of 7.0-9.5 using appropriate buffers. This parameter optimization maintains statin stability by preventing acid-catalyzed decomposition while the water-soluble polymer film prevents the adverse effects of alkaline conditions on gelatin solubility
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The approach stabilizes statin compounds and prevents gelatin coating insolubilization, ensuring good stability and bioavailability during manufacturing, distribution, and long-term storage, with improved yield and ease of production.
Implementation Method 1
a capsule coating has a pH adjusted to 7.0 to 9.5
Implementation Method 2
stabilizes statin compounds
Implementation Method 3
prevents gelatin coating insolubilization
Implementation Method 4
using hydroxypropyl methylcellulose (HPMC) on the inner surface for enhanced stability
Data Source
AI summary
Provided is a compound preparation including at least one selected from the group consisting of ω3 polyunsaturated fatty acids and pharmaceutically acceptable salts and esters thereof and at least one selected from the group consisting of statin compounds and pharmaceutically acceptable salts thereof. The compound preparation is in a form of a soft capsule having a capsule coating with a pH of 7.0 to 9.5. The compound preparation suppresses the decomposition of the statin compounds and/or the modification/insolubilization of the capsule coating. A medical use for the compound preparation, a method of manufacturing the compound preparation and a method of using the compound preparation are also provided.