PVP-PLA Block Copolymers for Low-Solubility API Delivery
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Solution Overview
Problem
Current PVP-PLA block copolymer technologies face challenges in efficient synthesis, limited ability to load different APIs, and variable API release profiles, making them inefficient for drug delivery, particularly for low-solubility APIs.
Innovation Solution
Development of PVP-PLA block copolymers with specific molecular weight ranges and structures, formed through controlled polymerization methods, to create stable micelles for API encapsulation and controlled release, including methods like organocatalytic coordination-insertion polymerization, and the use of xanthate macroinitiators for PLA polymerization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional PVP-PLA block copolymer synthesis methods are used, then the copolymers can be produced, but the synthesis is inefficient and not cost-effective
Solution Approach 1:
The patent applies parameter changes by optimizing the polymerization conditions including temperature (60-80°C), time (16-48 hours), and catalyst loading (0.1-1 wt%) to achieve efficient synthesis. The controlled radical polymerization parameters are carefully adjusted to produce copolymers with desired molecular weights and compositions while maintaining cost-effectiveness.
Solution Approach 2:
The patent uses xanthate macroinitiators as intermediaries in the synthesis process. These macroinitiators are prepared in advance and then used to initiate the polymerization of poly(D,L-lactide), enabling controlled block copolymer formation. This intermediary approach streamlines the synthesis and improves efficiency.
2Adaptability or versatility
If PVP-PLA is used for drug delivery, then micelles can be formed to deliver APIs, but the ability to load different APIs is limited
Solution Approach 1:
The patent creates universal PVP-PLA block copolymers with tunable hydrophobic block lengths that can accommodate multiple different APIs. By adjusting the polymer structure parameters (n and m values), the copolymers can be optimized for different drug types including hydrophobic, amphiphilic, and peptide drugs, making the delivery system versatile while maintaining reliable micelle formation and drug release.
3Quantity of substance
If PVP-PLA micelles are used to deliver APIs, then APIs can be entrapped within cores, but the amount of API that may be loaded is limited
Solution Approach 1:
The patent increases API loading capacity by changing the polymer structure parameters, specifically increasing the hydrophobic block length (higher n values) to provide larger micelle cores for drug entrapment. The copolymers are designed with Mn ≥ 3000 Da and specific n/m ratios to optimize both loading capacity and micelle stability. The controlled architecture ensures that even with high drug loading, the micelles maintain structural integrity.
4Adaptability or versatility
If PVP-PLA formulations are used for drug delivery, then APIs can be delivered to subjects, but the CMC varies depending on the nature of the entrapped API
Solution Approach 1:
The patent addresses CMC variability by systematically adjusting polymer concentration parameters and copolymer composition parameters for each API. The block copolymers are designed with specific n and m values that can be tuned to achieve optimal CMC values for different drug types. This parameter optimization approach allows flexible formulation for various APIs while maintaining manageable formulation complexity through established design guidelines.
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 new PVP-PLA block copolymers enable efficient encapsulation and controlled release of APIs, improving drug delivery by enhancing drug loading capacity and stability, allowing for more flexible and effective formulation of a range of APIs with reduced haemolytic effects.
Implementation Method 1
The technology has the ability to form micelles independently of the pH when the polymer concentration in water is above the critical micellar concentration (CMC) and to entrap APIs within their cores in the process
Implementation Method 2
Development of PVP-PLA block copolymers with specific molecular weight ranges and structures, formed through controlled polymerization methods, to create stable micelles for API encapsulation
Data Source
AI summary
There are provided PVP-PLA block copolymers as defined in Formula (1): I wherein, x is an initiator alcohol having a boiling point greater than I 45° C., n is, on average, from 20 and 40, and m is, on average, from 10 and 40, wherein the block copolymers have a number average molecular weight (Mn) of at least 3000 Da. Polymers demonstrating flexibility in formulating multiple low solubility active pharmaceutical ingredients (APis) are described. Liquid and dry pharmaceutical formulations comprising an API are described, along with delivery methods, uses, and kits. APis may include, e.g. 11urbiprofon, celecoxib, acetaminophen, or propofol. Also provided is a method of synthesizing the PVP-PLA block copolymers by (i) initiating polymerization of D,L-Lactide from the initiator alcohol x to form poly(lactic acid), adding a xanthate to form a PLA macroinitiator, and polymerizing NVP onto the PLA macroinitiator, by controlled polymerization, to form the block copolymer compound of Formula (I).