Delivery by Design (DbD): A Standardized Approach to the Development of Efficacious Nanoparticle‐ and Microparticle‐Based Delivery Systems

Abstract

The design and development of nanoparticle‐ and microparticle‐based delivery systems for the encapsulation, protection, and controlled release of active agents has grown considerably in the agrochemical, cosmetic, food, personal care, and pharmaceutical industries. These colloidal delivery systems can be utilized to overcome problems such as poor solubility, low activity, and chemical instability of active agents, as well as to create novel functional attributes such as controlled or targeted delivery. The purpose of this article is to develop a systematic approach, referred to as “delivery‐by‐design” (DbD), to make the design and fabrication process more efficient and effective. Initially, a brief review of some of the challenges associated with incorporating active agents into commercial products is given, and then an overview of different kinds of simple and complex colloidal delivery systems is given. The DbD approach is then presented as a series of stages: (1) definition of the molecular and physicochemical properties of the active agent; (2) definition of the required physicochemical, sensory, and functional attributes of the end‐product; (3) specification of the required attributes of the colloidal delivery system; (4) specification of particle properties and delivery system selection; (5) optimization of delivery system manufacturing process; (6) establishment and implementation of delivery system testing protocol; and (7) optimization of delivery system performance. Utilization of the DbD approach may lead to more rapid design of efficacious and economically viable colloidal delivery systems for commercial applications.

Design principles of food gels

“…Gel systems may assist in overcoming some problems associated with these health-beneficial substances, such as poor solubility, undesirable flavour organoleptic profiles and chemical instability. New functionalities may also be designed via ad hoc engineered gels, such as on-demand delivery at target points in the gastrointestinal tract [25][26][27]63,64 .…”

“…Another major feature of the gastrointestinal tract is the pH difference, which leads to alteration of the overall charge of food polymers. The varying degradation behaviours and charge features, in combination with the stable interior environment, make food hydrogels an ideal vehicle for the targeted delivery of the environmentally sensitive bioactives or drugs: the hydrogels protect the cargo from degradation within foods and certain regions of the gastrointestinal tract, but release them at an appropriate site of action [25][26][27]63,64 . The release of the encapsulated agents can take place via a number of mechanisms: swelling, disintegration, molecular interactions and erosion (Fig.…”

“…The release of the encapsulated agents can take place via a number of mechanisms: swelling, disintegration, molecular interactions and erosion (Fig. 6b) [25][26][27]63,64 . As an example, targeted proteins are entrapped in calcium alginate microgels at pH 3 (stomach) due to the opposite charges between protein and alginate, but are released when they both possess negative charges at pH 7 (small intestine) 115 .…”

“…This targeted delivery has advantages not only for the direct treatment of colonic disease, but also for systemic therapy by exploiting the long residence time in the colon (~12-24 h) 116 . The enzyme and pH responses of food gels can provide quite diverse delivery systems, which could be further enriched by differences in the temperatures and ionic strengths between the gel formulation and gastrointestinal fluids 25,26,63 .…”

Functional and Engineered Colloids from Edible Materials for Emerging Applications in Designing the Food of the Future

“…Unlike pharmaceuticals, the area of colloidal delivery systems can be considered to be somewhat of a recent phenomenon in foods where it has seen a surge in interest only in the past decade or so, as indicated in several excellent reviews published by some of the world leaders in this field . In fact, statistics published in a recent review suggests that the number of citations per year to paper with the keywords “delivery system” and “food” has increased from around 3 in 1990 to over 10 800 in 2017 ( Figure a) …”