Alprazolam Tablet Composition for Impurity G Stability Control
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Solution Overview
Problem
Alprazolam formulations containing commonly used pharmaceutically acceptable excipients, such as starch derivatives, cellulose, and magnesium stearate, are unstable and degrade to the genotoxic impurity G, which is accelerated by temperature and humidity, and the formation mechanism is not well understood.
Innovation Solution
A pharmaceutical composition of alprazolam using a specific combination of CaCO3 and microcrystalline cellulose as fillers, and crospovidone as a disintegrant, which significantly reduces the formation of impurity G, even under stress conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If commonly used pharmaceutically acceptable excipients (starch derivatives, cellulose, magnesium stearate) are used in alprazolam formulations, then the formulation is easy to manufacture and widely applicable, but the stability of alprazolam deteriorates and degradation to impurity G occurs
Solution Approach 1:
The patent changes the chemical parameters of the excipients by replacing traditional starch derivatives and cellulose with specific cellulose derivatives (hydroxypropyl cellulose, hydroxyethyl cellulose) and replacing magnesium stearate with calcium stearate or zinc stearate. This parameter change in excipient composition resolves the contradiction by maintaining ease of manufacture while eliminating the degradation pathway to impurity G, thereby improving stability.
Solution Approach 2:
The patent creates a composite excipient system combining specific cellulose derivatives (hydroxypropyl cellulose or hydroxyethyl cellulose) with calcium stearate or zinc stearate. This composite material approach allows the formulation to maintain the beneficial properties of traditional excipients (ease of manufacture, tabletability) while avoiding the harmful interactions that lead to impurity G formation, thus resolving the stability contradiction.
2Productivity
If alprazolam is stored at higher temperatures and higher humidity, then the dissolution and absorption may be improved, but the formation of impurity G is accelerated and stability deteriorates
Solution Approach 1:
The patent introduces specific cellulose derivatives (hydroxypropyl cellulose, hydroxyethyl cellulose) as intermediary substances that mediate between alprazolam and the environmental conditions (temperature and humidity). These intermediaries protect alprazolam from degradation by forming a stable matrix that prevents direct exposure to degrading conditions, while still allowing controlled dissolution at physiological conditions, thus resolving the contradiction between dissolution rate and stability.
3Ease of operation
If excipients bearing carboxyl groups (CMC, magnesium stearate) are used in alprazolam formulations, then the formulation has good tabletability and flow properties, but reactions between carboxyl functional groups cause increased formation of impurity G
Solution Approach 1:
The patent extracts and removes the harmful carboxyl-containing excipients (CMC, magnesium stearate) from the formulation and replaces them with alternative excipients that do not contain reactive carboxyl groups. The replacement excipients (calcium stearate, zinc stearate, hydroxypropyl cellulose, hydroxyethyl cellulose) maintain the necessary tabletability and flow properties without generating impurity G through carboxyl group reactions, thus resolving this contradiction.
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 composition achieves higher stability and reduced impurity G content, maintaining stability during storage without special handling requirements, and is suitable for various solid dosage forms.
Implementation Method 1
An analytical study of the degradation of alprazolam to impurity G by the Maillard reaction (a non-enzymatic reaction between a carbohydrate and an amino group) is described by A.L. Huidobro et al. in Anal Bioanal Chem (2009) 394: 1349-1359.
Implementation Method 2
The present invention relates to a pharmaceutical composition of alprazolam, which is suitable for use in a solid dosage form, having an increased stability of said composition and reduced content of impurity G.
Data Source
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AI summary
The present invention relates to a pharmaceutical composition comprising alprazolam, at least one pharmaceutically acceptable filler and at least one pharmaceutically acceptable disintegrant, wherein said pharmaceutically acceptable filler is CaCO3 and/or microcrystalline cellulose, and said disintegrant is crospovidone. Such a composition has better stability of alprazolam and lower content of impurity G than commercially available compositions.