Design and development of nanoemulsion drug delivery system of amlodipine besilate for improvement of oral bioavailability

Abstract

Nanoemulsion (NE) of amlodipine besilate (AB) was developed by spontaneous emulsification method with the aim to enhance the solubility and oral bioavailability of AB and to achieve localized delivery of drug at target site. Pseudoternary phase diagrams were constructed to identify the NE region. The selected formulations from NE region were subjected to droplet size analysis, partitioning study and in vitro drug release. The partition coefficient was calculated and correlated with percent dissolution efficiency as a tool to predict in vitro drug release from NEs. The release of drug from NEs was significantly higher (p < 0.01) than the marketed tablet formulation. The optimal formulation contained 15% Labrafil M, 35% [Tween 80: ethanol (2:1)], and 50% by weight aqueous phase (NE3) was characterized by transmission electron microscopy (TEM) and for thermodynamic stability. The pharmacokinetics and biodistribution studies of the optimized radiolabeled formulation (99mTc-labeled) in mice (p.o.) demonstrated a relative bioavailability of 475% against AB suspension. In almost all the tested organs, the uptake of AB from NE was significantly higher (p < 0.05) than AB suspension especially in heart with a drug targeting index of 44.1%, also confirming the efficacy of nanosized formulation at therapeutic site. A three times increase in the overall residence time of NE further signifies the advantage of NEs as drug carriers for enhancing bioavailability of AB.

Development of loteprednol etabonate-loaded cationic nanoemulsified in-situ ophthalmic gel for sustained delivery and enhanced ocular bioavailability

“…Surfactant and co-surfactants (S/CoS or S mix ) in altered weight proportions (1:1, 2:1, 3:1, 4:1) were selected and their concentration proportions were identified from available range of NEs (Kumar et al, 2009;Chhabra et al, 2011) for the study of phase diagrams. For every phase diagram, altered weight ratios of oil and S mix , 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 and 9:1 were prepared in distinct glass tubes to designate the boundaries of phases exactly made in all phase diagrams.…”

“…Particle size analyzer (Microtrac) working on the principle of dynamic light scattering was used to measure the globule size and polydispersity index (PDI) of NEs (Ammar et al, 2010;Chhabra et al, 2011;Pathak et al, 2012;Tayel et al, 2013). Globules of NEs have Brownian movement, which can vary the scattering light and measurement was carried out at 25 ± 1 C with 90 , after diluting samples with phosphate buffer saline.…”

Transdermal nanoemulsions of Foeniculum vulgare Mill. essential oil: Preparation, characterization and evaluation of antidiabetic potential

“…Thermodynamic stability was examined for the NE systems by centrifugation at 5000 rpm [22] for 20 min and examination of integrity and phase separation, using a tabletop centrifuge, Shanghai Surgical Instrument Factory, China. The formulations showing no phase separation, creaming or cracking were selected for further investigations.…”

“…Streptozotocin has been reported to be capable of generating reactive oxygen species resulting in oxidative stress and cell death [23] which may be one of the main causes of beta-cell destruction. Rats with fasting plasma glucose >250 mg/dl were considered diabetic [22,23]. A group of six rats was considered as normal healthy control group (Group I).…”

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“…[36] Globule size determination Globule size determination by dynamic light scattering with Zeta sizer HSA 3000 (Malvern Instruments Ltd, UK) were selected SEDDS were subjected to sonication was analyzed. [37] Zeta potential determination Zeta potential measurement of the selected SEDDS formulations (F1-F6) was subjected to sonication diluted with excess (100 times) double distilled water and then analyzed using Zetasizer (Malvern Instrument Ltd., UK). The instruments operating principle is based on the Doppler shift caused by the movement of globules across interference fringes which are produced by the intersection of two laser beams.…”