Use of transethosomes for enhancing the transdermal delivery of olmesartan medoxomil: in vitro, ex vivo, and in vivo evaluation

Rofida Albash,1 Aly A Abdelbary,2,3 Hanan Refai,1 Mohamed A El-Nabarawi2 1Department of Pharmaceutics, College of Pharmaceutical Sciences and Drug Manufacturing, Misr University for Science and Technology, Giza, Egypt; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt; 3Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, October 6 University, Giza, Egypt Introduction and aim: Olmesartan medoxomil (OLM) is an antihypertensive drug with low oral bioavailability due to extensive first-pass metabolism. This study aimed to prepare transetho­somes (TEs) for enhancing the transdermal delivery of OLM to avoid its oral problems. Methods: TE formulae were prepared utilizing 51.31 full factorial design using various surfactants (SAAs) and different phospholipid-to-SAA ratios. The formulae were characterized regarding their entrapment efficiency percentage (EE%), particle size (PS), polydispersity index (PDI), zeta potential (ZP), and the amount of drug released after 6 hours (Q6h). Design Expert® software was employed to select the optimum formula. Results: The optimum formula (TE14) had an EE% of 58.50%±1.30%, PS of 222.60±2.50 nm, PDI of 0.11±0.06, ZP of -20.80±0.30 mV, and Q6h of 67.40%±0.20%. In addition, TE14 was compared to transferosomes (TFs) in terms of elasticity and was found to show higher deformability index. Further, evaluation of ex vivo permeation using both rat and shed snake skin showed higher permeability of TE14 compared to TFs and OLM suspension. Confocal laser scanning microscopy confirmed the capability of the fluoro-labeled TE14 to penetrate deep within the skin, while the histopathological study confirmed its safety. TE14 successfully maintained normal blood pressure values of rats up to 24 hours. Moreover, TE14 showed superiority in dermatokinetic study when compared with drug suspension. Conclusion: Taken together, the obtained results confirmed the potential of employing TEs as a successful carrier for the transdermal delivery of OLM. Keywords: olmesartan medoxomil, transethosomes, factorial design, transdermal drug delivery, dermatokinetic study, confocal laser scanning microscopy, permeatio

Formulation, release characteristics, and bioavailability study of gastroretentive floating matrix tablet and floating raft system of Mebeverine HCl

Mohamed A El Nabarawi,1 Mahmoud H Teaima,1 Rehab A Abd El-Monem,2 Nagla A El Nabarawy,3 Dalia A Gaber4 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Misr University for Science and Technology, 6th of October, Egypt; 3National Egyptian Center of Environment and Toxicological Research (NECTER), Faculty of Medicine, Cairo University, Cairo, Egypt; 4Department of Quality Control, Holding Company for Biological Products and Vaccines, Cairo, Egypt Abstract: To prolong the residence time of dosage forms within the gastrointestinal tract until all drug is released at the desired rate is one of the real challenges for oral controlled-release drug delivery systems. This study was designed to develop a controlled-release floating matrix tablet and floating raft system of Mebeverine HCl (MbH) and evaluate different excipients for their floating behavior and in vitro controlled-release profiles. Oral pharmacokinetics of the optimum matrix tablet, raft system formula, and marketed Duspatalin® 200 mg retard as reference were studied in beagle dogs. The optimized tablet formula (FT-10) and raft system formula (FRS-11) were found to float within 34±5 sec and 15±7 sec, respectively, and both remain buoyant over a period of 12 h in simulated gastric fluid. FT-10 (Compritol/HPMC K,100M 1:1) showed the slowest drug release among all prepared tablet formulations, releasing about 80.2% of MbH over 8 h. In contrast, FRS-11 (Sodium alginate 3%/HPMC K,100M 1%/Precirol 2%) had the greatest retardation, providing sustained release of 82.1% within 8 h. Compared with the marketed MbH product, the Cmax of FT-10 was almost the same, while FRS-11 maximum concentration was higher. The tmax was 3.33, 2.167, and 3.0 h for marketed MbH product, FT-10, and FRS-11, respectively. In addition, the oral bioavailability experiment showed that the relative bioavailability of the MbH was 104.76 and 116.01% after oral administration of FT-10 and FRS-11, respectively, compared to marketed product. These results demonstrated that both controlled-released floating matrix tablet and raft system would be promising gastroretentive delivery systems for prolonging drug action. Keywords: GRDDS, Precirol®, Compritol®, HPMC, Na alginat

Transbuccal delivery of betahistine dihydrochloride from mucoadhesive tablets with a unidirectional drug flow: in vitro, ex vivo and in vivo evaluation

Mohamed A El-Nabarawi,1 Adel A Ali,2 Heba M Aboud,2 Amira H Hassan,2 Amany H Godah2 1Department of Pharmaceutics, Faculty of Pharmacy, Cairo University, Cairo, 2Department of Pharmaceutics, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt Objective: Betahistine dihydrochloride (BH.2HCl), an anti-vertigo histamine analog used in the treatment of Ménière’s disease, undergoes extensive first-pass metabolism and suffers from short biological half-life. The aim of the present work was to develop and estimate controlled release mucoadhesive buccal tablets of BH.2HCl with a unidirectional drug flow to overcome this encumbrance. Methods: A direct compression method was adopted for preparation of the tablets using mucoadhesive polymers like guar gum, hydroxypropyl methyl cellulose K4M, sodium carboxymethyl cellulose and their combinations. The tablets were coated from all surfaces except one surface with a solution of 5% (w/v) cellulose acetate and 1% (w/v) dibutyl phthalate. Different permeation enhancers like 2% sodium deoxycholate, 2% sodium cholate hydrate (SCH) and 5% menthol were tested. Swelling index, ex vivo residence time, mucoadhesion strength, in vivo testing of mucoadhesion time, in vitro dissolution and ex vivo permeation were carried out. Furthermore, compatibility and accelerated stability studies were performed for the drug excipients. Finally, drug bioavailability of the BH.2HCl-optimized buccal mucoadhesive formulation was compared with that of the orally administered Betaserc® 24 mg tablet in six healthy male volunteers. Results: Formulation F10, which contained a combination of 35% guar gum and 5% sodium carboxymethyl cellulose, exhibited long adhesion time, high adhesion strength and diminished irritation to volunteers and showed zero-order release kinetics. SCH produced a significant enhancement in permeation of BH.2HCl across buccal mucosa. BH.2HCl-optimized buccal mucoadhesive formulation showed percentage relative bioavailability of 177%. Conclusion: The developed mucoadhesive tablets represent a promising alternative for the buccal delivery of BH.2HCl. Keywords: betahistine dihydrochloride, transbuccal delivery, unidirectional drug flow, permeation enhancer, relative bioavailabilit

Pomegranate extract-loaded solid lipid nanoparticles: design, optimization, and in vitro cytotoxicity study

Noha M Badawi,1 Mahmoud H Teaima,2 Khalid M El-Say,3 Dalia A Attia,1 Mohamed A El-Nabarawi,2 Mohey M Elmazar4 1Department of Pharmaceutics, Faculty of Pharmacy, The British University in Egypt, Cairo, Egypt; 2Department of Pharmaceutics and Industrial Pharmacy, Cairo University, Cairo, Egypt; 3Department of Pharmaceutics, King Abdulaziz University, Jeddah, Saudi Arabia; 4Department of Pharmacology, Faculty of Pharmacy, The British University in Egypt, Cairo, Egypt Background: Pomegranate extract (PE) is a natural product with potent antioxidant and anticancer activity because of its polyphenols content. The main purpose of this study was to maximize the PE chemotherapeutic efficacy by loading it in an optimized solid lipid nanoparticles (SLNs) formula.Materials and methods: The influence of independent variables, which were lipid concentration (X1), surfactant concentration (X2) and cosurfactant concentration (X3), on dependent ones, which were particle size (Y1), polydispersity index (Y2), zeta potential (Y3), entrapment efficiency (Y4) and cumulative % drug release (Y5), were studied and optimized using the Box–Behnken design. Fifteen formulations of PE-SLNs were prepared using hot homogenization followed by ultra-sonication technique. Response surface plots, Pareto charts and mathematical equations were produced to study the impact of independent variables on the dependent quality parameters. The anti-proliferative activity of the optimized formula was then evaluated in three different cancer cell lines, namely, MCF-7, PC-3 and HepG-2, in addition to one normal cell line, HFB-4.Results: The results demonstrated that the particle sizes ranged from 407.5 to 651.9 nm and the entrapment efficiencies ranged from 56.02 to 65.23%. Interestingly, the 50% inhibitory concentration of the optimized formula had more than a 40-fold improved effect on the cell growth inhibition in comparison with its free counterpart. Furthermore, it was more selective against cancer cells than normal cells particularly in MCF-7 breast cancer cells.Conclusion: These data proved that nanoencapsulation of PE enhanced its anticancer efficacy. Therefore, our results suggested that a PE-loaded SLNs optimized-formula could be a promising chemo­therapeutic agent. Keywords: pomegranate extract, solid lipid nanoparticles, Box–Behnken design, optimization, cancer cell line