Advances in molecular pharmacology and an improved understanding of the mechanism of most diseases have created the need to specifically target the cells involved in the initiation and progression of diseases. This is especially true for most life-threatening diseases requiring therapeutic agents which have numerous side effects, thus requiring accurate tissue targeting to minimize systemic exposure. Recent drug delivery systems (DDS) are formulated using advanced technology to accelerate systemic drug delivery to the specific target site, maximizing therapeutic efficacy and minimizing off-target accumulation in the body. As a result, they play an important role in disease management and treatment. Recent DDS offer greater advantages when compared to conventional drug delivery systems due to their enhanced performance, automation, precision, and efficacy. They are made of nanomaterials or miniaturized devices with multifunctional components that are biocompatible, biodegradable, and have high viscoelasticity with an extended circulating half-life. This review, therefore, provides a comprehensive insight into the history and technological advancement of drug delivery systems. It updates the most recent drug delivery systems, their therapeutic applications, challenges associated with their use, and future directions for improved performance and use.

The potential enhancement of metformin hydrochloride (MH) loaded in lipid vesicles targeting therapeutic efficacy on alloxan-induced diabetic rats was investigated. This involved lipid vesicles formulated with homogenously distributed nano-sized particles by a novel integrated process of multiple emulsification by membrane and solvent evaporation. The average diameter of the water-in-oil (W₁/O), W₁/O/W₂ emulsion droplets, and lipid vesicles was 192 nm, 52 µm, and 173 nm, respectively. The entrapment yield of metformin hydrochloride (MH) in the prepared lipid vesicles was 40.12%. The metformin hydrochloride-loaded lipid vesicles (MH-LLVs) sustained the release of the entrapped drug over a 12-h period and reduced the plasma glucose level of diabetic rats by 77.4% compared with free MH solution (2-h period and 58.2%, respectively) after one week post-diabetic treatment through oral administration of MH-LLV and the free drug. The remarkable improvement in the biochemical parameters recorded in the MH-LLV-treated animals compared with those that received free MH solutions depicted an enhanced kidney function, liver function, as well as oxidative stress status. Pancreatic histology depicted a pancreas with intralobular ducts (ID) and exocrine secretory acini that characterize an intact pancreas, which suggests the ability of the MH-LLVs to restore pancreatic cells to normal, on a continued treatment. Overall, MH-LLV appears an encouraging extended-release formulation with enhanced bioavailability, sustained release, and improved antihyperglycemic potentials.

Characterization and further development of underutilized/underexploited indigenous tropical seed oils are essential to supplement both nutritional and industrial needs of an ever-increasing African (and global) population. Before now and to our best knowledge, the previous research involved Canarium schweinfurthii Engl. fruit specific to Nigeria appear to have been more on the evaluation of seed, pulp, and essential oils (from the seed), but much less on the pulp oil. To supplement existing information, this current work has aimed to biochemically characterize the Soxhlet-extracted pulp oil of C. schweinfurthii fruit gathered from a community situated in the South-east of Nigeria. Specifically, the biochemical characterization comprised the determinations of proximate compositions, lipid peroxidation, fatty acid profile, as well as carotenoids, sterols, and tocopherols. Processing the fruit sample to pulp oil involved, among others, oven-drying, and grinding, prior to the Soxhlet extraction. Results of proximate components of C. schweinfurthii pulp oil showed the following trend: crude fat content (~ 49.32%) > carbohydrates (~ 37.93%) > moisture content (~ 8.62%) > ash content (~ 3.74%) > crude protein content (~ 0.39%) values. The lipid peroxidation attributes comprised acid (~ 23.60 mg KOH/g), peroxide (~ 33.91 mEq. O₂/kg), iodine (~ 58.3 g/100 g), and saponification (~ 138.21 mg KOH/g) values. In addition to the free (~ 13.8%), saturated (~ 9.74%), and unsaturated (~ 90.26%) fatty acids, a total of fifteen (15) fatty acid methyl esters (FAMEs) spectral peaks were found, from caprylic acid (C8:0) to lignoceric acid (C24:0). Total tocopherol concentration amounted to ~ 73 mg/100 g, which comprised α, β, γ-tocopherol, and δ-tocotrienol, with fair concentrations of carotenoids and sterols. Overall, the C. schweinfurthii pulp oil—biochemically competitive with a high concentration of unsaturated fatty acid, tocopherol, and sterol, suggests strong industrial promise.