Pluronic-based organogels as versatile systems for topical drug delivery
The demand for medications is a relevant topic that meets efforts from different fields of science to develop new healthcare technologies. Hence, drug-delivery systems have been designed to maximize therapeutic efficacy and minimize adverse effects. Numerous innovative medicines have been proposed to achieve superior performance compared to conventional treatments. In this context, Organogels (ORGs) are semi-solid materials widely investigated for pharmaceutical and cosmetic applications, consisting of an organic phase (OP) immobilized by a three-dimensional lattice composed of a structured aqueous phase (AP). Poloxamers (Pluronics®, PL), thermosensitive block copolymers, were used in this work as the AP, while various oils were investigated as OPs. This thesis aims to present the design of PL-based ORGs towards different pharmacological applications focusing on topical drug delivery. In this sense, this work was organized as a brief introduction, results, and discussion about four publications, numbered I to IV, in which ORG formulations were designed for local anesthesia, skin inflammatory dermatosis, cutaneous leishmaniasis, and vaginal candidiasis. Publication I reported skin-delivery ORG formulations composed of lidocaine-loaded (LDC) oleic acid-lanolin (OA-LAN) associated with PL F-127, while Publication II addressed a mixture of two PLs with different hydrophilic-lipophilic balances (HLB), F-127 and L-81, as the AP containing OA for curcumin skin delivery. Publication III studied the development of ORGs composed of PL F-127 alone and PL F-127 / PL F-68 mixtures, combined with sodium alginate (SA), using oleic acid as the OP, aiming at the treatment of vaginal candidiasis. Finally, Publication IV proposed ORGs as dual drug-carrier systems in which lidocaine (LDC) and a synthetic monoketonic curcuminoid (m-CUR) were incorporated into the formulations. The composition and supramolecular organization of the ORGs were shown to be directly linked to their rheological parameters, consequently modulating skin permeation performance. Furthermore, two studies that are still in progress investigated several different OPs and APs to evaluate the impact of these compositions on the structure of ORGs and how these formulations interact with the skin. In summary, all the ORGs evaluated were structured and stable at the conditions required for their application. This feature allowed the incorporation of different additives, which provides new characteristics that can be designed depending on the target. These studies identified ORGs as promising formulations for topical delivery, with high potential for different pharmacological applications.