Mohammed Abdallah

The aim of this research was to formulate a novel nano-micellar complex carrier with intrinsically enhanced intestinal permeability for rosuvastatin calcium (RSV); as a model of BCS class III active pharmaceutical ingredients (APIs). The model drug is used primarily for treating hypercholesterolemia. Three phospholipid types with different degrees of saturation were chosen for the study. The saturation degree of the phospholipids was calculated accurately by proton NMR. A D-optimal statistical design was utilized to correlate the saturation degree of the phospholipids with the physico-chemical characteristics of the prepared nano-micellar carrier. The nature of the interaction between the phospholipids and the model drug was studied by proton NMR, photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM). Molecular docking and molecular dynamics simulations were performed to understand the formation mechanism of the complex micelles on a molecular level. The results demonstrated that the interaction of the hydrophilic drug molecule with the polar head of a saturated phospholipid induces an intramolecular self-coiling of phospholipid saturated acyl chain leading to a structural transformation from a two-tailed cylindrical configuration into a one-tailed, surfactant-like configuration owing to the flexibility of the saturated chains. This transformation leads to the construction of a novel nano-micellar structure in which the drug has lower water solubility but higher lipophilicity than in traditional micelles. Permeability studies conducted on Caco-2 cells demonstrated that the novel nano-micellar carrier had superior permeability to that of the un-complexed hydrophilic drug. The optimized nano-micellar formulation showed significantly (P < 0.5) superior bioavailability in rats to that of the aqueous drug solution in terms of both the rate and extent of drug absorption. Overall, the results confirmed that the formation of the phospholipid nano-micellar complex increased the permeability of the hydrophilic BCS class III drug and converted it to a class BCS I drug by a simple and effective formulation technique.

AbstractThe active compounds present in Hypericum perforatum L. (Hypericaceae) include hyperforin, hypericins and flavonoids, which are assumed to be responsible for the activity of the extract in the treatment of wounds and scars. The present study aimed to incorporate H. perforatum extract standardized to a known content of phloroglucinols, naphthodianthrones and polyphenolic compounds into an effective transdermal drug delivery system capable of entrapping both lipophilic and hydrophilic constituents in the form of niosomal gels for wound treatment. An 80% ethanol extract (HE) was prepared on a pilot scale using DIG-MAZ. An HPLC-DAD holistic profile was established for HE and was standardized to contain 3.4 ± 4 rutin, 1.1 ± 3 chlorogenic acid, 0.5 ± 2 quercitrin, 2.8 ± 2 hyperforin, and 0.51 ± 3% w/w total hypericins. Niosomes were prepared using the modified reverse phase evaporation technique (REV). The wound healing effect of the gel was tested on 16 adult mongrel dogs. A significant decrease in the inflammatory cell count (18.4 ± 5.3) was recorded in the niosomal gel 1.5% NaCMC-treated group at the 7th day post wounding. It induced a marked regression in the inflammatory phase and enhanced the early beginning of the proliferative phase of wound healing. After 21 days, it showed complete re-epithelization, formation of new matrix fibers and significant reduction in the wound size, compared to the control and the Panthenol® 2% cream treated groups. This is the first study of H. perforatum in a niosomal topical drug delivery system.

AbstractAtorvastatin (AT) is a widely used lipid-regulating drug to reduce cholesterol and triglycerides. Its poor aqueous solubility and hepatic metabolism require development of drug delivery systems able to improve its solubility and bypass hepatic effect. For this purpose, atorvastatin nanostructured lipid carriers (AT-NLCs) were prepared and characterized. AT-NLCs were prepared by emulsification using high-speed homogenization followed by ultrasonication. The prepared NLCs showed particle size between 162.5 ± 12 and 865.55 ± 28 nm while zeta potential values varied between −34 ± 0.29 and −23 ± 0.36 mV. They also showed high encapsulation efficiency (>87%) and amorphous state of the drug in lipid matrix. Pharmacokinetic parameters of optimized formulation (NLC-1; composed of 2% Gelucire® 43/01, 8% Capryol® PGMC, 2% Pluronic®F68 and 0.5% lecithin) revealed 3.6- and 2.1-fold increase in bioavailability as compared to atorvastatin suspension and commercial product (Lipitor®), respectively. Administration of NLC-1 led to significant reduction (p < .05) in the rats’ serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and significant increase in high-density lipoprotein (HDL). This improvement was confirmed histologically by minimizing the associated hepatic steatosis. These investigations demonstrated the superiority of NLCs for improvement of oral bioavailability and in vivo performance of AT.