Osama Ahmed

Prof. Osama Ahmed

Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University
orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 April 2020 in Pharmaceutics
Verified
Journal Article
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NANabil A. Alhakamy
Nabil A. Alhakamy
UFUsama Fahmy
Usama Fahmy
SBShaimaa Badr-Eldin
Shaimaa Badr-Eldin
OAOsama Ahmed
Osama Ahmed
HAHani Z. Asfour
Hani Z. Asfour
AMAmir I. Mohamed
Amir I. Mohamed
Icariin (ICA) is a flavonol glycoside that has pleiotropic pharmacological actions. It has cytotoxic effects against ovarian cancer cells and increases their chemosensitivity to chemotherapeutic drugs. Phytosomes are identified for their potential in drug delivery of cytotoxic agents. Thus, the purpose of this study was to determine the potential enhancement of ICA cytotoxicity activity in OVCAR-3 ovarian cancer cells via its formulation in phytosomes. ICA-phytosomal formulation was optimized using a Box–Behnken design. Particle size, shape, and in vitro drug release were used to characterize the optimized formula. The optimized formulation exhibited enhanced in vitro drug release. ICA-phytosomes exhibited enhanced cytotoxicity against ovarian cancer cells. Cell cycle analysis indicated accumulation of cells challenged with ICA-phytosomes in G2/M and pre-G1 phases. Staining of cells with annexin V indicated significant elevation of percentage cells with early and late apoptosis as well as total cell death. In addition, the formulation significantly disturbed mitochondrial membrane potential and cellular content of caspase 3. In addition, intracellular release of reactive oxygen species (ROS) was enhanced by ICA-phytosomes. In conclusion, phytosome formulation of ICA significantly potentiates its cytotoxic activities against OVCAR-3 cells. This is mediated, at least partly, by enhanced ICA cellular permeation, apoptosis, and ROS.

19 January 2016 in Journal of Liposome Research
Verified
Journal Article
Closed access
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MKMallesh Kurakula
Mallesh Kurakula
OAOsama Ahmed
Osama Ahmed
UFUsama Fahmy
Usama Fahmy
AAAhmed Al-Abd
Ahmed Al-Abd
Context: Avanafil (AVA) is used in the treatment of erectile dysfunction, but is reported for its poor aqueous solubility. Solid lipid nanoparticles (SLNs) are lipid carriers that can greatly enhance drug solubility and bioavailability. Objective: This work was aimed to formulate and optimize AVA SLNs with subsequent loading into hydrogel films for AVA transdermal delivery. Materials and methods: AVA SLNs were prepared utilizing homogenization followed by ultra-sonication technique. The prepared SLNs were characterized for particle size, charge, surface morphology and drug content. The optimized SLNs formulation was incorporated into transdermal films prepared using HPMC and chitosan. Hydrogel films were evaluated for ex-vivo rat skin permeation using automated Franz diffusion cells. The permeation parameters and the release mechanism were evaluated. The transdermal permeation of the prepared AVA SLNs through the skin layers was studied using confocal laser scanning microscope. Results: Lipid concentration and % of oil in lipid had a pronounced effect on particle size while, entrapment efficiency was significantly affected by lipid concentration and % of cholesterol. The optimized AVA SLNs showed particle size and entrapment efficiency of 86 nm and 85.01%, respectively. TEM images revealed spherecity of the particles. High permeation parameters were observed from HPMC films loaded with AVA SLNs. The release data were in favor of Higuchi diffusion model. The prepared AVA SLNs were able to penetrate deeper in skin layers. Conclusion: HPMC transdermal film-loaded AVA SLNs is an effective and alternative to per-oral drug administration.

12 August 2020 in Pharmaceutics
Verified
Journal Article
Open access
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NANabil A. Alhakamy
Nabil A. Alhakamy
SBShaimaa Badr-Eldin
Shaimaa Badr-Eldin
UFUsama Fahmy
Usama Fahmy
Nabil AlruwailiNabil Alruwaili
Nabil Alruwaili
ZAZuhair Ahmed Awan
Zuhair Ahmed Awan
AAAdel F. Aalghaith
Adel F. Aalghaith
Thymoquinone (TQ), a natural polyphenol, has been associated with various pharmacological responses; however, low bioavailability of TQ limits its clinical application. Thus, a novel phytosomal delivery system of TQ-Phospholipon® 90H complex (TQ-phytosome) was developed by refluxing combined with anti-solvent precipitation. This TQ delivery system was optimized by a three-factor, three-level Box-Behnken design. The optimized TQ-phytosome size was (45.59 ± 1.82 nm) and the vesicle size was confirmed by transmission electron microscopy. The in vitro release pattern of the formulation indicated a biphasic release pattern, where an initial burst release was observed within 2 h, followed by a prolonged release. A remarkable increase in dose-dependent cytotoxicity was evident from the significant decrease in IC50 value of TQ-phytosomes (4.31 ± 2.21 µM) against the A549 cell line. The differential effect of TQ-phytosomes in cell cycle analysis was observed, where cancer cells were accumulated on G2-M and pre-G1 phases. Furthermore, increased apoptotic induction and cell necrosis of TQ-phytosomes were revealed with the annexin V staining technique via activation of caspase-3. In reactive oxygen species (ROS) analysis, TQ-phytosomes acted to significantly increase ROS generation in A549 cells. In conclusion, the sustained release profile with significantly-improved anticancer potential could be obtained with TQ by this phytosomal nanocarrier platform.

1 April 2016 in Drug Design, Development and Therapy
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Journal Article
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SBShaimaa Badr-Eldin
Shaimaa Badr-Eldin
OAOsama Ahmed
Osama Ahmed
Sildenafil citrate (SLD) is a selective cyclic guanosine monophosphate-specific phosphodiesterase type 5 inhibitor used for the oral treatment of erectile dysfunction and, more recently, for other indications, including pulmonary hypertension. The challenges facing the oral administration of the drug include poor bioavailability and short duration of action that requires frequent administration. Thus, the objective of this work is to formulate optimized SLD nano-transfersomal transdermal films with enhanced and controlled permeation aiming at surmounting the previously mentioned challenges and hence improving the drug bioavailability. SLD nano-transfersomes were prepared using modified lipid hydration technique. Central composite design was applied for the optimization of SLD nano-transfersomes with minimized vesicular size. The independent variables studied were drug-to-phospholipid molar ratio, surfactant hydrophilic lipophilic balance, and hydration medium pH. The optimized SLD nano-transfersomes were developed and evaluated for vesicular size and morphology and then incorporated into hydroxypropyl methyl cellulose transdermal films. The optimized transfersomes were unilamellar and spherical in shape with vesicular size of 130 nm. The optimized SLD nano-transfersomal films exhibited enhanced ex vivo permeation parameters with controlled profile compared to SLD control films. Furthermore, enhanced bioavailability and extended absorption were demonstrated by SLD nano-transfersomal films as reflected by their significantly higher maximum plasma concentration (Cmax) and area under the curve and longer time to maxi­mum plasma concentration (Tmax) compared to control films. These results highlighted the potentiality of optimized SLD nano-transfersomal films to enhance the transdermal permeation and the bioavailability of the drug with the possible consequence of reducing the dose and administration frequency.

1 June 2018 in International Journal of Nanomedicine
Verified
Journal Article
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MAMohammed Abdelwahab Sayed Abourehab
Mohammed Abdelwahab Sayed Abourehab
OAOsama Ahmed
Osama Ahmed
GBGehan F Balata
Gehan F Balata
WAWaleed H Almalki
Waleed H Almalki
Background: Dapoxetine (DPX) is the drug of choice for the specific treatment of premature ejaculation. DPX is characterized by relatively low bioavailability (42%) and short half-life (1.5 h). The aim of this study was to improve DPX bioavailability and delivery across the blood–brain barrier (BBB) using a nanostructured DPX formulation for improved DPX efficacy and patient satisfaction. Materials and methods: DPX-loaded polymeric micelles (PMs) formulations (F1–F3) were characterized for particle sizes, entrapment efficiencies, and Fourier transform infrared spectroscopic and transmission electron microscopic evaluations. In addition, diffusion profiles of the prepared formulations were investigated. Animal model pharmacokinetic parameters in plasma and brain tissues were investigated and compared with commercial DPX tablets. Results: Particle size analysis revealed that formulations of DPX PMs showed a narrow range of 62.7±9.3–45.45±9.1 nm for F1–F3. In addition, DPX PMs showed a sustained release pattern with 91.27%±7.64%, 79.43%±7.81%, and 63.78%±5.05% of DPX content permeated after 24 h for F1, F2, and F3, respectively. Plasma pharmacokinetic parameters for DPX PMs showed significant increase (P<0.05) for the area under drug concentration–time curves in plasma and brain tissues compared with commercial DPX tablets. Conclusion: DPX formulations in the form of PMs improved bioavailability and efficacy across the BBB. This DPX formulation provided improved brain delivery in order to enhance the convenience and compliance of patients.