Formulations

Due to their unique properties and benefits, lipid play a vital role in formulation development. Lipids have different solubility characteristics, which can affect the formulation of lipid products. This solubility property facilitates the formulation of lipids into different types of products such as emulsions, suspensions or solid lipid nanoparticles. In addition, lipids can act as a protective barrier against degradation or oxidation of active ingredients, thereby enhancing formulation stability. They form a stable matrix that protects active compounds from environmental factors such as light, heat or moisture. Lipids can also be used in pharmaceutical formulations to control the release rate of active ingredients. They can form a matrix or encapsulate a drug for sustained or targeted release. By manipulating lipid composition and structure, the release profile of active compounds can be tailored to meet specific therapeutic needs.

Fig. 1. Lipids encapsulate drug molecules (Mol. Pharmaceutics. 2017, 14(5): 1325-1338).

Composition and Type of Lipid Formulations

The component selection of lipid preparations needs to fully consider the physical and chemical properties of the drug, the affinity between the drug and lipid excipients, the pharmacokinetic requirements, and the dosage form of the future drug (oral milk/liquid soft capsule/hard capsule), etc. The formula composition usually includes grease, and (or) surfactants, and (or) small molecule co-solvents/co-solvents, etc. Types of lipid formulations, generally divided into 4 categories:

Type I: Composition of pure oil phase, the dispersion process of this type of preparation in the gastrointestinal tract basically does not affect the solubilization of the drug, but the digestion process usually has a greater impact on the solubilization of the drug.

Type II: Composition of oil with water-insoluble surfactant. The dispersion process of this type of preparation in the gastrointestinal tract basically does not affect the solubilization of the drug, but the digestion process may affect the solubilization of the drug.

Type III: Composition of oil with water-soluble surfactant with solvent, this type of preparation has the ability of self-emulsification, usually forms nanoparticles with small particle size and uniform distribution, which can be directly absorbed by intestinal epithelial cells. During the dispersion and digestion process in the gastrointestinal tract, it may affect the solubilization and absorption of the drug.

Type IV: Composition of water-soluble surfactant with solvent (without oil). This type of preparation does not contain oil. The dispersion process may have a greater impact on the solubilization of the drug, but the impact on the digestion process is relatively small.

Fig. 2. Lipid-based nanocarriers in oral drug delivery (Drug Delivery and Translational Research. 2021, 11: 471-497).

Lipid Formulation Applications

Delivery of Poorly Water Soluble Compounds

Lipid-based formulation design is a preferred delivery route for poorly absorbed drugs with poor solubility in the gastrointestinal tract, or with pH-dependent solubility. Drugs that have been marketed, such as cyclosporine soft capsules, olaparib capsules, enzalutamide soft capsules, etc., all use lipid solubilization technology.

Delivery of Liquid Fat-Soluble or Volatile Drugs

Lipid formulations have become ideal for the administration of liquid fat-soluble compounds (eg, vitamin E, fish oil). Lipid formulations are also ideal for volatile drugs. For example, the oil solution of butylphthalide is delivered in the form of soft capsules, which not only has the effect of masking bad smell, but also avoids the volatilization of active ingredients, ensuring the stable quality of the drug.

Delivery of Low Doses of Poorly Soluble Compounds

The oil solution after drug dissolution is a homogeneous dispersion system, which can avoid technical problems such as poor drug content uniformity for products with small dosage specifications. For example, the marketed drugs such as calciferol or calcitriol have a specification of only 0.25ug, and have been industrialized through the design of lipid dosage forms.

Leading Supplier of Lipid Formulated Products

BOC Sciences offers a line of lipid formulation products designed to improve the delivery and bioavailability of lipophilic drugs and compounds. Our lipid formulation products include lipid-based drug delivery systems such as liposomes, lipid nanoparticles and solid lipid nanoparticles. These formulations are composed of lipids that can encapsulate hydrophobic drugs and enhance their solubility, stability, and targeted delivery. In addition, custom lipid formulation development services are also available at BOC Sciences to meet specific requirements such as particle size, drug loading and surface modification.

References

1. Li, F. et al. Lipid-Drug Conjugate for Enhancing Drug Delivery. Mol. Pharmaceutics. 2017, 14(5): 1325-1338.
2. Lozano, M.V. et al. Current approaches in lipid­‑based nanocarriers for oral drug delivery. Drug Delivery and Translational Research. 2021, 11: 471-497.