Improving patient-centricity with advanced polymer excipients

With the increasing empowerment of patients and the greater priority regulators now place on the patient experience, today’s drug developers must consider not only therapeutic performance but also how formulations fit into patients’ lives. This is crucial for improving treatment adherence, given that as many as three in four patients fail to take their medication as directed, with implications for their ongoing health.

Excipients now play a strategic role in addressing these challenges, with advances in polymer technology enabling new approaches to enhancing solubility, drug loading, stability and sensory optimisation. These capabilities directly support the development of drugs that are easier to administer, more tolerable and better aligned with patients’ real-world needs.

To highlight the opportunities of patient-centric formulation, Lubrizol has introduced a range of patient personas. These demonstrate how targeted excipient selection can help manufacturers overcome barriers to compliance with oral, parenteral and topical formats.

Transforming parenteral delivery through advanced solubilisation

Marisol requires life-changing treatment and she is keen to use formats that minimise disruption to her busy schedule. Parenteral formulations will play a key role in her treatment, yet many therapeutics used in injectable dosage forms have extremely low aqueous solubility. This can translate into higher drug volumes and, potentially, longer administration times, which can be inconvenient and unpleasant for patients like Marisol who depend on regular treatment.

Polymeric excipients based on amphiphilic block copolymers… [support] higher drug loading and can reduce the number of required drug administrations”

Polymeric excipients based on amphiphilic block copolymers offer an alternative by solubilising hydrophobic APIs to enable effective dispersion in an aqueous environment. This approach supports higher drug loading and can reduce the number of required drug administrations.

Lubrizol’s novel Apisolex™ polymer excipient is an injectable-grade, poly-amino acid-based amphiphilic polymer. It enables substantial increases in solubility of up to 10²-10⁵-fold for both amorphous and crystalline APIs, alongside high drug-loading of up to 40:100 API:solubiliser. These capabilities allow more API to be delivered in a lower volume, helping to reduce administration time or frequency. Based on sarcosine, it offers a biocompatible, biodegradable, non-toxic and non-immunogenic profile that also improves patient tolerability.

For patients who rely on parenteral therapies but need their treatment to fit around work, family or travel commitments, such innovations can significantly improve their overall healthcare experience.

Delivering high-dose oral therapeutics in smaller tablets

College rugby player Lydia has been diagnosed with a chronic condition that requires oral treatments with a high dosage level. This can mean bulky, hard-to-swallow tablets or multiple smaller dosages, yet Lydia prefers to use easy-to-take tablets that fit seamlessly into her active lifestyle.

Oral dosage forms are the most convenient delivery route for many chronic conditions. Improving API solubility to enable higher drug loading is a key strategy for reducing tablet size or dosing frequency without compromising therapeutic efficacy. Amorphous solid dispersions (ASDs) are widely used to enhance gastrointestinal dissolution of poorly soluble APIs, disrupting their crystalline structure to increase their surface area. However, many commonly used ASD polymer excipients, such as HPMC, enable drug loading of only up to 40%, which limits the scope for reducing tablet size.

Lubrizol’s novel polymer excipient [enables] significantly higher drug loading of up to 80% for spray-dried ASDs – double that of many HPMC-based excipients”

Lubrizol’s novel Apinovex™ polymer excipient addresses this limitation by enabling significantly higher drug loading of up to 80% for spray-dried ASDs – double that of many HPMC-based excipients. It also delivers up to tenfold improvements in dissolution compared with crystalline APIs. Compatible with a wide range of APIs, it maintains ASD stability even after six months under accelerated conditions, making it a versatile option for oral solid formulations.

For patients who require high-dose oral therapeutics but prefer smaller, easier-to-take tablets or less frequent dosing, these benefits can meaningfully improve compliance and long-term health outcomes.

Enhancing the acceptability and usability of paediatric therapeutics

Young mother Tayesha is caring for her son Henri, who has been recommended an oral medication in either a solid or liquid format. Henri is reluctant to swallow large pills, and they both struggle with oral suspension formulations, which are unpalatable and easily spilt.

Excipients that allow for high drug loading are key for formulating smaller tablets”

Up to four in ten children find it difficult to swallow even normal-sized pills, so excipients that allow for high drug loading are key for formulating smaller tablets. Oral suspensions can be a valuable alternative but present their own challenges, including sedimentation and poor taste. These issues can reduce acceptability for children, who are particularly sensitive to texture and flavour. Ensuring that oral suspensions remain smooth, stable and palatable is therefore critical.

Lubrizol’s Carbopol^® polymer excipients offer several advantages for paediatric oral therapeutics. For oral solid dosage formats, they support higher drug loading and a controlled release profile, enabling smaller tablets that are easier to swallow and optimise API delivery. With oral suspensions, they stabilise dispersed particles, preventing sedimentation. Their rheology-modifying properties allow formulators to create liquids with a smooth, pourable texture that reduces the risk of spillage and improves dosing accuracy. They can also contribute to taste-masking, helping mitigate API bitterness that is otherwise difficult for children to tolerate.

These excipient attributes can improve treatment acceptability in young patients and make it easier to administer paediatric oral dosage formats.

Improving efficacy in topical and mucosal delivery

Claire wants to actively manage some of the symptoms she is experiencing in menopause, including vaginal dryness related to oestrogen loss. She has been prescribed an estradiol cream administered via localised vaginal delivery.

Effective localised drug delivery to mucosal tissues requires formulation with mucoadhesive excipients that remain in place long enough to achieve a therapeutic effect. These excipients also reduce the amount of API required, minimising potential side effects and improving tolerability.

Lubrizol’s Carbopol^® polymer excipients provide strong mucoadhesion, lubrication and moisturisation for topical vaginal application, while helping maintain physiological vaginal pH. They are hydrophilic and can interact with mucin glycoproteins via non-covalent bonds through hydrogen bonding or inter-chain penetration when neutralised. This allows for enhanced drug permeation and consistent, prolonged drug release. In a study designed to extend the duration of action of a vaginal gel, Carbopol polymers achieved a threefold increase in retention at 45 minutes compared with the original formulation.

For symptom management with topical therapies, improved retention and tolerability can significantly enhance quality of life.

A strategic role for excipients in patient-centric formulation

Excipient optimisation is key for patient-first drug design, helping to overcome challenges such as poor solubility, usability issues and unpleasant side effects or sensory profiles. These advanced technologies enable effective therapeutics that are more acceptable to patients and better suited for long-term use. By helping manufacturers to align formulations with real-world patient needs, the right excipient can support enhanced compliance and, ultimately, better health outcomes.

Explore Lubrizol’s patient personas here.