Ahmed Elshafeey

The current medical practice in treating Hepatocellular carcinoma (HCC) using Drug Eluting Transarterial chemoembolization (DEB-TACE) technique is limited only to hydrophilic ionizable drugs, that can be attached ionically to the oppositely charged beads. This limitation has forced physicians to subscribe the more hydrophobic, first treatment option drugs, like sorafenib systemically via the oral route, thus flooding the patient system with a very powerful, non-specific, multiple-receptor tyrosine kinase inhibitor that is associated with notorious side effects. In this paper, a new modality is introduced, where highly charged, drug loaded liposomes are added to oppositely charged DEBs in a manner causing them to “explode” and the drug is eventually attached to the beads in the lipid patches covering their surfaces; therefore we call them “Explosomes”. After fully describing the preparation process and in vitro characterization, this manuscript delves into an in vivo pharmacokinetic study over 50 New Zealand rabbits, where explosomal loading is challenged vs oral as well as current practice of emulsifying sorafenib in lipiodol. Over 14 days of follow up, and compared to other groups, explosomal loading of SRF on embolic beads proved to cause a slower release pattern with longer Tmax, lower Cmax and less washout to general circulation in healthy animals. This treatment modality opens a new untapped door for local sustained delivery of hydrophobic drugs in catheterized organs. © 2023 Elsevier B.V.

AbstractThe aim of this work was to develop a novel and more efficient platform for sublingual drug delivery using mosapride citrate (MSP) as a model drug. The engineering of this delivery system had two stages, the first stage was tuning of MSP physicochemical properties by complexation with pure phosphatidylcholine or phosphatidylinositol enriched soybean lecithin to form MSP-phospholipid complex (MSP-PLCP). Changes in physicochemical properties were assessed and the optimum MSP-PLCP formula was then used for formulation into a flushing resistant platform using two mucoadhesive polymers; sodium alginates and sodium carboxymethylcellulose at different concentrations. Design of experiment approach was used to characterize and optimize the formulated flushing resistant platform. The optimized formulation was then used in a comparative pharmacokinetics study with the market formulation in human volunteers. Results showed a marked change in MSP physicochemical properties of MSP-PLCP compared to MSP. Addition of mucoadhesive polymers to flushing resistant platform at an optimum concentration balanced between desired mucoadhesive properties and a reasonable drug release rate. The optimized formulation showed significantly a superior bioavailability in humans when compared to the market sublingual product. Finally, the novel developed sublingual flushing resistant platform offers a very promising and efficient tool to extend the use of sublingual route and widen its applications.

The aim of this study was to investigate the influence of the nanocarrier surface charge on brain delivery of a model hydrophilic drug via the nasal route. Anionic and cationic nanostructured lipid carriers (NLCs) were prepared and optimized for their particle size and zeta potential. The optimum particles were incorporated in poloxamer in situ gels and their in vivo behavior was studied in the plasma and brain after administration to rats. Optimum anionic and cationic NLCs of size <200 nm and absolute zeta potential value of ≈34 mV were obtained. Toxicity study revealed mild to moderate reversible inflammation of the nasal epithelium in rats treated with the anionic NLCs (A7), and destruction of the lining mucosal nasal epithelium in rats treated with the cationic NLCs (C7L). The absolute bioavailability of both drug loaded anionic and cationic NLCs in situ gels was enhanced compared to that of the intranasal solution (IN) of the drug with values of 44% and 77.3%, respectively. Cationic NLCs in situ gel showed a non significant higher Cmax (maximum concentration) in the brain compared to the anionic NLCs in situ gel. Anionic NLCs in situ gel gave highest drug targeting efficiency in the brain (DTE%) with a value of 158.5 which is nearly 1.2 times that of the cationic NLCs in situ gel. © 2014 Elsevier B.V.

The pharmacokinetic and bioavailability of fenoterol, a B2 adrenergic agonist were studied to determine the feasibility of enhanced transdermal delivery. Fenoterol has been widely used to treat asthmatic patients. Two fenoterol formulations were studied; the first was a liquid formulation of fenoterol in Transcutol: Oleic acid in a ratio 1:1(F1), while the second was a matrix system of fenoterol in Duro-tak® 87-2074 adhesive with 10% 1-dodecyl-2-pyrrolidinone as an enhancer (F2). For comparison, control matrix with fenoterol without any enhancer (F3) was also tested. The tested formulations were applied to the shaved back skin of rabbits using HILL TOP CHAMBER® in case of liquid formula. Blood samples were collected via auricle central vein for 24 hours and the plasma concentrations of fenoterol were determined by LC-MS/MS method. Pharmacokinetic parameters were calculated using the WinNonlin computer program. The results showed a maximum concentration of fenoterol in plasma of 514.8 ng/ml after application of the liquid formula while its AUC0-∞ amounted to be 485972(ng*min/ml) with a dose of 3mg/kg. The transdermal matrix prepared with 10% 1-dodecyl-2-pyrollidinone had a Cmax of 219 ng/ml and AUC0-∞ was 124636 (ng*min/ml) which is significantly higher than that obtained after application of the control patch without any enhancer. Therefore, the transdermal systems will offer an efficient drug delivery system for the treatment of bronchial asthma. © 2011 Elshafeey AH, et al.