Non-aqueous Oily Injectable Preservative Efficacy

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Solution Overview

Problem

Current injectable formulations, especially non-aqueous oily ones, face challenges in achieving high preservative efficacy against microorganisms, particularly when used in multi-dose applications, as traditional lipophilic preservatives often fail to maintain sterility effectively.

Innovation Solution

A non-aqueous injectable formulation combining a therapeutically effective amount of an active ingredient dissolved or suspended in oil with a hydrophilic excipient and a lipophilic preservative, where the hydrophilic excipient is non-phase separable from the oil, enhancing preservative efficacy by increasing the concentration of the preservative in the water phase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lipophilic preservative is used alone in non-aqueous oily injectable formulation, then the formulation can maintain stability, but preservative efficacy against microorganisms is insufficient

Engineering Contradiction:
Improvepreservative efficacyVSAvoidformulation composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines lipophilic preservative and hydrophilic excipient into a composite preservative system. The lipophilic preservative (e.g., phenol, cresol, benzyl alcohol) provides oil-phase stability while the hydrophilic excipient (e.g., propylene glycol, polyethylene glycol) creates a water-miscible phase that microorganisms require for growth. This composite approach achieves high preservative efficacy without requiring multiple separate components.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the concentration ratio between lipophilic preservative and hydrophilic excipient to achieve phase compatibility. By adjusting parameters such as the amount of hydrophilic excipient (typically 0.1-10% w/v) and lipophilic preservative (typically 0.01-5% w/v), the formulation achieves both microorganism inhibition and physical stability without phase separation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If hydrophilic excipient is added to increase preservative efficacy, then preservative ability improves, but phase separation may occur

Engineering Contradiction:
Improvepreservative efficacyVSAvoidphase stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent carefully controls the concentration parameters of hydrophilic excipient within specific ranges (typically 0.1-10% w/v) to prevent phase separation. By optimizing these parameters, the formulation maintains a single-phase system where the hydrophilic excipient enhances preservative efficacy without causing oil-water separation or affecting the stability of the active ingredient suspension.

Inventive Principle:
Principle #35Parameter changes

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 formulation demonstrates significantly higher preservative efficacy, reducing bacterial and fungal counts by 3-4 logs within 6 hours to 7 days, ensuring the sterility and stability of the injectable over time, even in low water activity states.

Implementation Method 1

a lipophilic preservative combined with a hydrophilic excipient, which may exhibit higher preservative efficacy, compared to administration of the preservative alone

Methodology Applied
Scientific EffectPhase partitioning:

Data Source

PatentUS9161981B2Non-aqueous oily injectable formulation exhibiting preservative efficacy
Publication Date: 2015.10.20 LG CHEM LTD

AI summary

Disclosed herein is preferably a multi-dose type non-aqueous oily injectable formulation including; an active ingredient (drug) expressing therapeutic effects, which is dissolved, dispersed or suspended in a therapeutically effective amount, in oil. The disclosed non-aqueous oily injectable formulation may include; an oil-affinitive preservative, and a hydrophilic excipient non-phase separable from the oil-affinitive preservative when the excipient is mixed with the oil-affinitive preservative.