Development and Permeability Testing of Self-Emulsifying Atorvastatin Calcium Pellets and Tablets of Compressed Pellets

Self-emulsifying pellets (SEPs) of Atorvastatin Calcium (AtrCa) were developed and processed into tablets (SETs). Self-emulsifying drug delivery system (SEDDS) composed of oleic acid, Tween 20, Span 80 and N-Methyl-2-pyrolidone gave great solubility improvement and was used as oil in water emulsion for the preparation of SEPs. Due to the high 60% w/w SEDDS content required to achieve a therapeutic dose in the final tablet form, sonication was necessary to improve fluidity and stability. Colloidal silicon dioxide (CSD) and microcrystalline cellulose (MCC) were the solids in the pellet formulation employed at a ratio 7:3, which enabled production of pellets with high SEDDS content and acceptable friability as well. Emulsions were characterized physico-chemically, SEPs for physical properties and reconstitution, and tablets of compressed pellets for mechanical strength, disintegration into pellets and drug release. SEPs compressed with 30% MCC at 60 MPa gave tablets of adequate strength that disintegrated rapidly into pellets within 1 min. Emulsion reconstitution took longer than drug release due to adsorption of SEDDS on CSD, implying dissolution at the pellet surface in parallel to that from the dispersed droplets. Compared to the commercial tablet, drug release from the self-emulsifying forms was faster at pH 1.2 where the drug solubility is poor, but slower at pH 6.8 where the solubility is higher. Permeability and cytotoxicity were also studied using Caco-2 cells. The results showed that drug transport from the apical to basolateral compartment of the test well was 1.27 times greater for SEPs than commercial tablets, but 0.86 times lower in the opposite direction. Statistical analysis confirmed the significance of these results. Toxicity was slightly reduced. Therefore, the increased permeability in conjunction with the protection of the drug being dissolved in the SEDDS droplets, may reduce the overall effect of presystemic metabolism and enhance bioavailability.

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Effect of Freezing and Thawing Process on Betamethasone Acetate Release from Polyvinyl Alcohol Nanospheres

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.151.159 ◽

2009 ◽

Vol 151 ◽

pp. 159-165 ◽

Cited By ~ 2

Author(s):

Shahin Bonakdar ◽

Seyed Ali Poursamar ◽

Mohammad Rafienia ◽

Mohammad A. Shokrgozar ◽

Afshin Farhadi ◽

...

Keyword(s):

Drug Release ◽

Polyvinyl Alcohol ◽

Freezing And Thawing ◽

Drug Release Rate ◽

Water Emulsion ◽

Transmission Electron ◽

Oil In Water ◽

Thawing Process ◽

Freezing Cycle ◽

Oil In Water Emulsion

Betamethasone acetate (BA) is a glucocorticoid steroid with anti-inflammatory and immunosuppressive properties which can be used in treatment of asthma and itching. In this research, polyvinyl alcohol nanospheres loaded by betamethasone acetate were prepared by oil in water emulsion method after which they were exposed to 1, 2 and 4 cycles of freeze-thawing (F-T) process including 24 hours freezing cycle at -25 °C and 24 hours thawing at ambient temperature. Nanospheres fabrication was confirmed by transmission electron microscopy and betamethasone release was analyzed by UV spectrophotometer at 245 nm. The results revealed that by increasing the number of F-T cycles the rate of drug release decreased. The effect of BA concentration was also investigated on human chondrosarcoma (sw 1353). The MTT assay was utilized to assess the cell proliferation. The results showed that these biocompatible nanospheres can be used for sustained release of such drugs for more than four months and drug release rate can be effectively controlled by implementing F-T cycles.

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Synthesis, In Vitro Antioxidant Properties and Distribution of a New Cyanothiophene-Based Phenolic Compound in Olive Oil-In-Water Emulsions

Antioxidants ◽

10.3390/antiox9070623 ◽

2020 ◽

Vol 9 (7) ◽

pp. 623

Author(s):

Sonia Losada-Barreiro ◽

Matej Sova ◽

Janez Mravljak ◽

Luciano Saso ◽

Carlos Bravo-Díaz

Keyword(s):

Olive Oil ◽

Volume Fraction ◽

Antioxidant Properties ◽

Tween 20 ◽

Interfacial Region ◽

Water Emulsion ◽

Narrow Region ◽

Oil In Water ◽

Oil In Water Emulsion

We synthesized and determined the antioxidant activity and distribution of a new cyanothiophene-based compound, N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-3,5-dihydroxybenzamide (SIM-53B), in intact stripped olive oil-in-water emulsion. The in vitro antioxidant properties of SIM-53B were evaluated and compared to those for Trolox and resveratrol. Addition of an emulsifier (Tween 20) creates a narrow region, the aqueous–oil interface, and the distribution of SIM-53B can be described by two partition constants: PWI (between aqueous/interfacial regions) and POI (between oil/interfacial regions). The effects of emulsifier concentration expressed in terms of the volume fraction, ΦI, and O/W ratio were also evaluated on its distribution. SIM-53B is predominantly distributed (>90%) in the interfacial region of 1:9 (O/W) olive oil-in-water emulsions at the lowest emulsifier volume fraction (ΦI = 0.005) and only a small fraction is located in the aqueous (<5%) and the oil (<5%) regions. Besides, the concentration of SIM-53B in the interfacial region of the emulsions is ~170–190-fold higher than the stoichiometric concentration, emphasizing the compartmentalization effects. Results suggest that the emulsifier volume fraction is a key parameter that may modulate significantly its concentration in the interface. Our study suggests that cyanothiophene-based compounds may be interesting additives for potential lipid protection in biomembranes or other lipid-based systems.

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