Extended-release formulations are those that release the drug at a slow, non-constant rate as required in a defined release medium, are administered half as often or somewhat less frequently than regular formulations, and significantly increase patient compliance when compared to regular formulations. Controlled-release formulations are formulations that release drugs slowly and at a constant rate in a defined release medium, where the frequency of administration is reduced by half or somewhat less than that of ordinary formulations, where the blood concentration is smoother than that of sustained-release formulations, and where patient compliance can be significantly increased.
In the sustained and controlled release drug delivery system, the excipients added to control the release rate, time lag or site, collectively referred to as the sustained and controlled release materials, the nature of the drug and the way of drug binding is the key to determine the performance of drug release. In the slow-release formulation, the excipients that can make the drug dissolve or diffuse slowly from the formulation are collectively called sustained-release materials, and in the controlled-release formulation, the excipients that can make the drug dissolve or diffuse at a constant rate from the formulation are collectively called controlled-release materials. In terms of delaying the release of drugs, controlled-release & sustained-release formulations with many of the same materials, due to their mixing with the drug, combined with different ways or processes, and show different characteristics of drug release.
Subtypes of Sustained & Controlled Release Materials
Polymers
Polymeric materials are widely used as sustained and controlled release materials. They can be classified into different categories based on their release mechanisms, such as diffusion-controlled systems (e.g., hydroxypropyl methylcellulose, ethyl cellulose), matrix systems (e.g., poly(lactic-co-glycolic acid), polyvinyl alcohol), and reservoir systems (e.g., polymeric microspheres, nanoparticles). Polymers offer advantages such as versatility, biocompatibility, and tunable release profiles.
Lipid-Based Materials
Lipid-based materials, such as liposomes and lipid nanoparticles, are utilized for sustained and controlled release of lipophilic drugs. These materials provide a lipid bilayer structure that encapsulates the API, enabling controlled release through diffusion or erosion of the lipid matrix. Lipid-based materials offer advantages such as enhanced drug solubility, improved stability, and targeted delivery.
Inorganic Materials
Inorganic materials, including mesoporous silica, hydroxyapatite, and zeolites, are used as carriers for sustained and controlled release applications. These materials possess unique structural properties, such as high surface area and pore volume, which allow for the adsorption and release of APIs. Inorganic materials offer advantages such as controlled release kinetics, stability, and the potential for surface modification to achieve specific release profiles.
Applications of Sustained & Controlled Release Materials
Oral Drug Delivery
Sustained and controlled release materials find extensive applications in oral drug delivery systems. They enable the controlled release of APIs, reducing the frequency of dosing and maintaining therapeutic drug levels over an extended period. These materials are used in the formulation of tablets, capsules, and multiparticulate systems for various therapeutic areas, including chronic diseases, pain management, and hormone replacement therapy.
Transdermal Drug Delivery
Sustained and controlled release materials are employed in transdermal drug delivery systems, allowing for the controlled absorption of APIs through the skin. These materials provide a barrier that regulates the release of the drug, ensuring a constant and controlled delivery over a prolonged period. Transdermal patches and films formulated with these materials offer advantages such as improved patient compliance, reduced side effects, and sustained therapeutic efficacy.
Injectable Drug Delivery
Sustained and controlled release materials are utilized in injectable drug delivery systems, enabling the sustained release of APIs directly into the bloodstream or targeted tissues. These materials can be formulated as microspheres, implants, or hydrogels, providing a controlled release profile and minimizing the need for frequent injections. Injectable formulations with sustained release capabilities are used in areas such as contraception, pain management, and treatment of chronic conditions.
Conclusion
Sustained & controlled release materials play a crucial role in the pharmaceutical industry, enabling the controlled and prolonged release of APIs for optimal therapeutic outcomes. Working with Protheragen-ING, a professional supplier, supports the creation of stable and effective pharmaceutical products by ensuring the availability of high-quality excipients. Please get in touch with us by phone or email if you have any excipient needs, and we'll get back to you within 2-4 working days.
