Lactic acidosis is a serious, metabolic complication that may occur due to metformin hydrochloride (MH) accumulation during the treatment of diabetes mellitus. The aim of this study is to enhance the bioavailability of MH by oral route. Span 40 and cholesterol were used for the preparation of MH-loaded niosomes by the reverse phase evaporation technique. Dicetyl phosphate (DCP) and 1,2-dioleoyl-3-trimethylammonium-propane chloride salt (DOTAP) were used to obtain negatively and positively charged vesicles, respectively. The mean particle size ranged from 223.5 to 384.6 nm and the MH-loaded niosomes' surface was negatively charged in the absence of charge inducing agents (-16.6 ± 1.4 mV) and also with DCP (-26.9 ± 1.0 mV), while it was positively charged (+8.7 ± 1.2 mV) with DOTAP. High entrapment efficiency was observed in all the formulations. MH-loaded niosomes were found to effectively sustain the release of drug, particularly with positively charged niosomes. The bioavailability of MH-loaded niosomes was assessed by measuring the serum values of glucose and metformin in the different studied Wistar rats groups. The pharmacokinetic data of MH-loaded niosomal preparation showed a significant prolongation and increased intensity of hypoglycemic effect more than that observed for free MH solution. Area above the blood glucose levels-time curve (AAC), maximum hypoglycemic response and time of maximum response (T(max)) were significantly higher (p < 0.001) when MH was administered in niosomal form compared to free drug solution. It could be concluded that MH-loaded niosome is promising extended-release preparation with better hypoglycemic efficiency.

Objective: The aim of this study is to formulate and evaluate proniosomal gel formulations as transdermal delivery systems of glimepiride (GM) to improve its therapeutic efficacy. Methods: Proniosomal formulations have been prepared using different types of non-ionic surfactants with cholesterol in different molar ratios. Proniosomal gel; PN 16 (Span 60, Tween 60, Cholesterol; 35:35:30 molar ratio) that exhibits maximum EE % (94.01 ± 0.88) and most prolonged release was chosen for ex-vivo skin permeation and in-vivo hypoglycemic activity studies. Results: Proniosomal gel produced better permeation through rabbit skin than HPMC niosomal gel and HPMC gel. The pharmacokinetic parameters; time of maximum response (T max ), % reduction in blood glucose concentration and area above the blood glucose levels-time curve (AAC) of proniosomal gel were studied. Proniosomal gel showed a control led release behavior and a significantly higher hypoglycemic activity (65.34 ± 6.54%). Conclusion: It is evident from this study that proniosomal gel can act as an alternative approach for enhancing transdermal delivery of GM.

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The objective of this work was to formulate and characterize non-ionic surfactant vesicles (niosomes) as an ocular carrier of dorzolamide hydrochloride (Dorzo); one of the antiglaucoma drugs. Niosomes were prepared of Cholesterol (Chol) with sorbitan monoesters (Span 20, 40, 60) or sorbitan trioleate (Span 85) in a molar ratio of 40:150. Those prepared from Span 40 were selected for further investigation on the effect of addition of dicetylphosphate (DCP) and polyoxyethylene fatty acid esters (either Tween 20, 40 or 80). All The batches were prepared using mechanical shaking technique, followed by sonication and then characterized using Zetasizer, transmission electron microscopy (TEM), calculating percent drug entrapment efficiency and cumulative percent released. Z-average sizes of the niosomes were between 25.9 and 165.5 nm. All niosomal formulations showed negative zeta potential charge. Dorzo was successfully entrapped in all of the formulations with entrapment efficiencies ranging between 34.81% and 97.66%. With reference to release profiles, Dorzo-loaded niosomal formulations showed significant reduction in cumulative percent drug released than Dorzo solution. High entrapment efficiencies, biphasic prolonged release rate and small particles size highlight Dorzo-loaded niosomal preparations as a promising ophthalmic carrier to prolong the drug lowering effect on the intraocular pressure.

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The main objective of this study was to design positively charged Levofloxacin Hemihydrate (Levo-h)-loaded nanoparticles with improved entrapment efficiency and antibacterial activity. PLGA alone or in combinations with Eudragit® RLPO or RS30D with or without positively charged inducing agent; 1,2-dioleoyl-3-trimethylammonium-propane, chloride salt (DOTAP); were used for preparation of nanoparticles. Blending between PLGA and Eudragit® RLPO or RS30D with inclusion of DOTAP caused a marked increase in entrapment efficiency and switched zeta potential from negative to positive. Nanoparticle formulations; NR3 (Levo-h:PLGA:Eudragit® RLPO; 1:1:1 w/w with DOTAP) and NS3 (Levo-h:PLGA:Eudragit® RS30D; 1:1:1 w/w with DOTAP) that possess high positive zeta potential (59.3 ± 7.5 and 55.1 ± 8.2 mV, respectively) and Efficient Levo-h entrapment (89.54 ± 1.5 and 77.65 ± 1.8%, respectively) were selected for further examinations; in vitro release, physical stability and microbiological study. NR3 and NS3 showed significant sustained release of Levo-h. NR3 and NS3 exhibited good stability after storage at room temperature. Microbiological assay showed strengthened antibacterial activity of NR3 against both types of gram-negative bacteria (E. coli, Ps. aeruginosa) and of NS3 against Ps. aeruginosa compared to free Levo-h solution. NR3 and NS3 appear to be promising oral delivery system for Levo-h.