Evolution of Nanotechnology in Delivering Drugs to Eyes, Skin and Wounds via Topical Route

Abstract

The topical route is the most preferred one for administering drugs to eyes, skin and wounds for reaching enhanced efficacy and to improve patient compliance. Topical administration of drugs via conventional dosage forms such as solutions, creams and so forth to the eyes is associated with very low bioavailability (less than 5%) and hence, we cannot rely on these for delivering drugs to eyes more efficiently. An intravitreal injection is another popular drug delivery regime but is associated with complications like intravitreal hemorrhage, retinal detachment, endophthalmitis, and cataracts. The skin has a complex structure that serves as numerous physiological barriers to the entry of exogenous substances. Drug localization is an important aspect of some dermal diseases and requires directed delivery of the active substance to the diseased cells, which is challenging with current approaches. Existing therapies used for wound healing are costly, and they involve long-lasting treatments with 70% chance of recurrence of ulcers. Nanotechnology is a novel and highly potential technology for designing formulations that would improve the efficiency of delivering drugs via the topical route. This review involves a discussion about how nanotechnology-driven drug delivery systems have evolved, and their potential in overcoming the natural barriers for delivering drugs to eyes, skin and wounds.

Cellulosic Polymers for Enhancing Drug Bioavailability in Ocular Drug Delivery Systems

“…On localized retention in a cul-de-sac, the drug can be delivered under external stimuli such as light or by diffusion. NP can overcome the ocular barriers, maintaining an optimal concentration and drug permeability [92]. Liposomes are large in size as they contain electrostatic attraction between the positive and negative charges of polymers and phospholipids [93].…”

Current Insights on Antifungal Therapy: Novel Nanotechnology Approaches for Drug Delivery Systems and New Drugs from Natural Sources

“…In the mycology field, amphotericin-B is the active substance that represents the majority of the nanomedicines already available in the market: Amphotec ® (Three Rivers Pharmaceuticals, approved in 1992), Abelcet ® (Sigma-Tau, approved in 1995) and Ambisome ® (Gilead Sciences, approved in 1997), all lipid-based formulations [191,192]. An econazole liposomal formulation (Pevaryllipogel ® ) is also available on the market [193]. In Table 5 some examples of recent clinical trials are presented.…”

3D-Printed Products for Topical Skin Applications: From Personalized Dressings to Drug Delivery

“…Pharmaceutics 2021, 13, x FOR PEER REVIEW 3 of 41 skin factors that can affect active ingredient delivery across the skin, such as the skin barrier function, provided mainly by the stratum corneum, skin hydration, anatomical site, pathological effects, age, ethnicity and gender, among others [27]. Hydration is also an important factor that influences penetration, as well hydrated areas provide better permeation conditions [28].…”

“…Other concerns about topical skin delivery are allergic reactions and the high frequency of dose applications, which could be overcome through innovative technologies [28]. Based on this scenario, new topical cutaneous drug delivery systems that can provide more precise doses and drug release rates, targeting specific skin areas, and be focused on the patient's needs, would be very much appreciated.…”