Systemic absorption of morphine after ocular administration: evaluation of morphine salt insert in vitro and in vivo

Anti-Cancer Nanofibrous Bandage Based on PVA Nanofibers Loaded with Gefitinib for Skin Cancer Treatment

Cancer is one of the leading causes of death worldwide, requiring sophisticated and versatile treatment options. As the enabling concept, nanotechnology has emerged to improve the efficacy of the current treatment strategies and eliminate their shortcomings and limitations. Accordingly, the main purpose of the current study is to develop a topical drug delivery system for Gefitinib (Gef), an EGFR inhibitor, based on the electrospun nanofibers. Electrospinning was applied to fabricate PVA nanofibers with different concentrations of Gef, 5, 7.5, and 10 wt.%, and the SEM imaging showed that the nanofibers were straight, uniform, and beadles. The results showed that adding Gef did not significantly compromise the mechanical strength of nanofibers. The fabricated anticancer nanofibrous bandage exhibited a burst drug release following a sustained release profile. The cell lethality assay revealed that the treatment of the cells with the Gef-loaded nanofibers induced dose-dependent toxicity, which is valuable for the intended anticancer application. The results of the present study showed that Gef can be loaded into PVA nanofibers without disrupting the morphology and mechanical properties of the nanofibers and can be applied as topical drug delivery for skin cancer.

Review on the systemic delivery of insulin via the ocular route

Systemic drug absorption from the ocular route is well known. Although there is some absorption from the conjunctival sac, the nasal meatus is the site where the majority of systemic absorption of instilled drug takes place. This article reviews the principles of systemic absorption of insulin applied topically to the eye. The physiological and pharmaceutical considerations for formulation development and the strategy of improving the systemic absorption and bioavailability of insulin are also discussed.

Minimizing systemic absorption of topically administered ophthalmic drugs

Due to absorption several ocularly applied medications give rise to systemic side-effects. The problem of systemic drug absorption should be taken into account in designing ocular drug and dosage forms so that oculospecificity of the medications is optimized. In this review we summarize the current knowledge about the systemic absorption of ocularly applied topical drugs. Special emphasis is directed to the methods that can be used to minimize systemic absorption and increase the oculospecificity of drugs, e.g., reducing volume and increasing viscosity of eyedrops, controlling drug release from depot preparations, prodrug-derivatization, and addition of vasoconstrictive agents.

Systemic morphine pharmacokinetics after ocular administration

Pharmacokinetics of a single dose of morphine ocularly applied is reported in rabbits before and after lacrimal canaliculi ligature. Our investigations are based on a sensitive reversed-phase ion-pair chromatographic determination of morphine. This study describes the various resorption sites of morphine when administered through the conjunctiva. After ocular administration, morphine rapidly reaches high blood levels compatible with pharmacological activity. Ocular bioavailability of morphine is higher than after non-parenteral routes. Canaliculi ligature modifies the morphine pharmacokinetic profile without significant modification of drug bioavailability. Our results suggest a great capacity of drug resorption for the conjunctiva, and indicate the major role of nasal mucosa in physiological conditions.