mSAS® strategies for enabling simplified formulations

Drug substance formulation is an important part of pharmaceutical development, but it is an often complex, multi-step process, which can add considerable time and expense to development programmes.

Crystec’s mSAS® (modified Supercritical Anti-Solvent) technology can offer a variety of strategies to target optimised therapeutic performance with simplified formulations.

Single step, high yielding process

One of the key advantages of mSAS® is the ability to simultaneously control a range of particle properties, reducing the number of process steps from Active Pharmaceutical Ingredient (API) to the final dosage form. Conventional crystal and particle engineering processes may include multiple steps including crystallisation, harvesting, drying, milling and sieving, with each step introducing opportunities for contamination, product losses or other process failures. In contrast, mSAS® is a single step and highly reproducible process where particles are precipitated directly from solution to generate a uniform and consistent product. Furthermore, once optimised, the mSAS® process typically achieves yields in excess of 95%.

Fewer or no excipients

Formulation is often an iterative process, where excipients are added in order to mitigate the consequences of previous processing steps. For example, mechanical milling is often employed to reduce particle size and increase rates of dissolution, but unintended consequences can include the formation of amorphous regions, the introduction of static charge, and an increased propensity for agglomeration. To reduce the impact of these features on product stability and performance, a wide range of excipients are frequently used.

mSAS® allows a high degree of control over particle formation, tuning solid-state form, particle size, shape and composition, in a single step, bottom-up precipitation process. As a result, mSAS® particles have smooth, low energy surfaces, producing free flowing powders without the need for subsequent downstream formulation. For a visual demonstration comparing the flow properties of mSAS® powders with a micronised equivalent, please watch our video below:

Matching performance of complex formulations

Many marketed products are developed via complex formulation processes in order to achieve the required therapeutic performance. One example of this is Sporanox®, an itraconazole formulation prepared by a multi-step process to generate multiple layered coatings onto sugar cores, to overcome dissolution challenges. The final product contains only 20% API loading.

Crystec have applied mSAS® technology to generate micron-sized, polymer stabilised composite particles of amorphous itraconazole, with 40% drug loading, from a single step process. Furthermore, the mSAS® product can be tuned to demonstrate equivalent or superior dissolution performance to Sporonox®.

In-vivo (beagle dog) evaluation of plasma concentration over time – mSAS® itraconazole vs Sporanox®

Uniform delivery of combination products

In addition to tuning solid state and surface properties of particles, Crystec’s single-step mSAS® technology can also be applied to generate composite particles containing a uniform mixture of multiple therapeutic agents. This can prove attractive in development and manufacture of fixed dose combination products due to the ability to eliminate blend uniformity challenges. mSAS® composite particles also offer a unique opportunity to facilitate synergistic delivery of inhaled combination products, ensuring that each agent is deposited at the same site in the lung, in the correct ratio. For more information about how mSAS® can support the development of optimised inhaled therapies, please read our blogpost.

In-particle design® formulation

By taking a “right first time” approach to product development and targeting defined particle properties from the first experiments, the need for excipients can be markedly reduced. Where the use of excipients cannot be avoided, such the incorporation of enhancing agents to support dissolution, API and excipients can be combined reproducibly with a uniform and intimate association throughout each particle. This can help to avoid the blend uniformity challenges common to conventional mixing processes, and in many cases, reduce excipient loading requirements. Overall, by combining the control and versatility of Crystec’s mSAS® technology with an in-particle design® approach, product performance can be optimised with simple formulations, streamlining manufacturing processes and reducing development timelines.

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