HIV Prodrug Crystallization for Improved Flow

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Solution Overview

Problem

Current methods for formulating HIV attachment inhibitor phosphate ester prodrug compounds with excipients, such as hydroxypropyl methyl cellulose (HPMC), face challenges due to the compound's fragile needle-like structure, low bulk density, and poor flow capabilities, leading to stability issues in both dry and wet granulation techniques.

Innovation Solution

A process involving the dissolution of the prodrug in a solvent, addition of anti-solvents, and dispersion of HPMC to crystallize the compound with a combination of acetone and isopropyl acetate, followed by filtering, washing, and agitated drying to produce spherical-shaped agglomerates with improved physical characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the prodrug compound is formulated using conventional dry or wet granulation techniques, then the API can be combined with excipients, but the fragile needle-like structure results in poor flow capability and low bulk density, leading to stability issues

Engineering Contradiction:
Improveformulation stabilityVSAvoidflow capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the physical state and morphology parameters of the prodrug compound by converting fragile needles into spherical agglomerates through a controlled crystallization process. This involves dissolving the prodrug in a solvent system (acetonitrile/water), adding anti-solvent (ethyl acetate), and controlling crystallization conditions to form spherical particles with improved flow and bulk density characteristics while maintaining formulation stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transitions during the crystallization process. The prodrug is dissolved in the liquid phase, then upon addition of anti-solvent and controlled cooling, transitions to solid crystalline spherical agglomerates. This phase transition from dissolved state to controlled crystallization enables formation of spherical morphology with improved physical properties

Inventive Principle:
Principle #36Phase transitions

2Productivity

If the prodrug compound is processed to improve flow and bulk density, then handling and tabletting become easier, but the fragile needle-like structure may be further damaged, reducing API integrity

Engineering Contradiction:
Improvetabletting efficiencyVSAvoidAPI structural integrity
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent performs preliminary action by pre-forming spherical agglomerates of the prodrug compound before final formulation and tabletting. This pre-crystallization step creates mechanically robust spherical particles that can withstand subsequent handling, mixing, and tabletting operations without damaging the API structure, thereby improving both productivity and structural integrity

Inventive Principle:
Principle #10Preliminary action

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 resulting formulation has high API content, improved bulk density, good flow characteristics, and high compactability, enabling the production of pharmaceutical-grade tablets with excellent extended release properties.

Implementation Method 1

dissolving the prodrug in a solvent to form a solution

Methodology Applied
Scientific EffectSolvation: Solvation

Implementation Method 2

adding anti-solvents, and dispersion of HPMC to crystallize the compound with a combination of acetone and isopropyl acetate

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 3

agitated drying to produce spherical-shaped agglomerates with improved physical characteristics

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2793862B1Co-processing method and formulation for HIV attachment inhibitor prodrug compound and excipients
Publication Date: 2016.12.07 VIIV HEALTHCARE UK (NO 4) LTD
  • EP2793862B1 patent drawingFigure 1
  • EP2793862B1 patent drawingFigure 2A~2B
  • EP2793862B1 patent drawingFigure 3A~3B

AI summary

A process for the production of a formulation of HIV attachment inhibitor piperazine tris salt prodrug compound involves dissolving the prodrug compound in a solvent to form a solution; adding a first quantity of a first anti-solvent to the solution; then dispersing a first quantity of HPMC in the solution; adding a second quantity of the first anti-solvent to the solution; dispersing a second quantity of HPMC in the solution; then adding a second anti-solvent to the solution so as to crystallize the compound with the HPMC and thereby form the formulation, wherein the second anti-solvent is a combination of acetone and isopropyl acetate (IPAC). The formulation is then washed, and dried.