Transdermal drug delivery: feasibility for treatment of superficial bone stress fractures

Liposomes as multifaceted delivery system in the treatment of osteoporosis

Introduction: Treatment of osteoporosis with the available drug formulations is still challenging due to multiple associated limitations such as chronic treatment, off-target side effects, poor bone targeting, and low bioavailability. Adopting advanced bone-targeted drug delivery strategies like liposomes is one of the safe and effective approaches for osteoporosis treatment.Areas covered: This review summarizes the applications of liposomes in gene delivery, bone regeneration, bone-targeted delivery, and as a carrier for drug encapsulation in the treatment of osteoporosis. Details of all the supportive studies are discussed here and the bone-specific roles of the strategies like new generation liposomes in osteoporosis are elaborated. The future scope of performing in-depth research on the bone-targeted liposomes is discussed.Expert opinion: Liposomes-based bone-targeted delivery of therapeutics seems to be a promising approach for the effective treatment of osteoporosis. But till date, the tremendous in vitro and in vivo research on liposomes has failed to attain significant progress in their clinical translation. From bench to bedside success of the research an interdisciplinary collaboration between the preclinical and clinical experts engaged at different stages of liposomes development is required.

Percutaneous delivery of levetiracetam as an alternative to topical nonsteroidal anti-inflammatory drugs: formulation development, in vitro and in vivo characterization

The study focused on formulation of carmellose sodium hydrogels and nonionic microemulsions with 5% and 10% of levetiracetam and investigation of drug concentration influence on their physicochemical characteristics and in-use stability as well as influence of drug concentration and carrier type on in vitro drug release and in vivo antihyperalgesic/antiedematous activity in a rat model of localized (intraplantar) carrageenan-induced inflammation. Hydrogels were pseudoplastic semisolids with thixotropy and pH 7.37-7.58. Microemulsions were low viscous Newtonian nanodispersions of oil droplets (13.11-15.11 nm) in water, with pH 4.01-4.64. Physical stability of the investigated systems was preserved over the 3-month storage under ambient conditions. Levetiracetam release followed zero order and Korsmeyer-Peppas models (R² ≥ 0.99) reflecting the combined effects of drug concentration and carrier viscosity. All levetiracetam-loaded formulations produced significant reduction of hyperalgesia and paw swelling induced by carrageenan (p < 0.001). Their efficacy in exerting antihyperalgesic activity was significantly higher than that observed with the reference 5% ibuprofen hydrogel preparation (up to 6 h) (p < 0.001), while antiedematous activity was comparable with the reference product. No erythema and visible blood vessels were observed in a rat ear test. The study demonstrated percutaneous delivery of levetiracetam as useful and safe therapeutic option for localized inflammatory pain with potential to overcome the insufficient efficacy of topically applied nonsteroidal anti-inflammatory drugs in the form of a hydrogel. Graphical abstract.

Nano-formulation for topical treatment of precancerous lesions: skin penetration, in vitro, and in vivo toxicological evaluation

With the aim of improving the topical delivery of the antineoplastic drug 5-fluorouracil (5FU), it was loaded into ultradeformable liposomes composed of soy phosphatidylcholine and sodium cholate (UDL-5FU). The liposome populations had a mean size of 70 nm without significant changes in 56 days, and the ultradeformable formulations were up to 324-fold more elastic than conventional liposomes. The interaction between 5FU and the liposomal membrane was studied by three methods, and also release profile was obtained. UDL-5FU did penetrate the stratum corneum of human skin. At in vitro experiments, the formulation was more toxic on a human melanoma-derived than on a human keratinocyte-derived cell line. Cells captured liposomes by metabolically active processes. In vivo toxicity experiments were carried out in zebrafish (Danio rerio) larvae by studying the swimming activity, morphological changes, and alterations in the heart rate after incubation. UDL-5FU was more toxic than free 5FU. Therefore, this nano-formulation could be useful for topical application in deep skin precancerous lesions with advantages over current treatments. This is the first work that assessed the induction of apoptosis, skin penetration in a Saarbrücken penetration model, and the toxicological effects in vivo of an ultradeformable 5FU-loaded formulation.