scholarly journals Intensification process in thyme essential oil nanoemulsion preparation based on subcritical water as green solvent and six different emulsifiers

2021 ◽  
Vol 10 (1) ◽  
pp. 430-439
Author(s):  
Omid Ahmadi ◽  
Hoda Jafarizadeh-Malmiri

Abstract In order to alter the solubility and bioavailability of various functional lipids and plant essential oils (EOs), it is possible to prepare their oil in water (O/W) nanoemulsions. Thyme O/W nanoemulsions were prepared under subcritical water conditions (at 120°C and pressure of 1.5 atm for 2 h), using Tween 20, Tween 80, saponin, Arabic gum, xanthan gum, and sodium caseinate as emulsifiers. Results indicated that nanoemulsions with minimum mean droplet size of 11.5 and 12.6 nm were produced using Tween 20 and 80, respectively. Moreover, nanoemulsions with minimum polydispersity index (0.139) and maximum mean value of zeta potential (−24.5 mV) were provided utilizing xanthan gum and saponin, respectively. Results also revealed that the prepared nanoemulsions using saponin had maximum antioxidant activity based on percentage of scavenging ability (40.6%) and bactericidal effects against Streptococcus mutans as manifested in the formed clear zone (diameter of 21 mm). Morphological assessment of all the prepared nanoemulsions demonstrated that spherical thyme nanodroplets were formed in the colloidal solutions which revealed that all the prepared nanoemulsions had high thermodynamic stability due to the minimum surface energy level of the formed nanodroplets. This can increase applications of the prepared thyme O/W nanoemulsions in the aqueous food and pharmaceutical formulations.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zahra Nourzadeh ◽  
Navideh Anarjan ◽  
Gholamreza Ebrahimzadeh Rajaei ◽  
Hoda Jafarizadeh-Malmiri

Abstract Vitamin D, like other functional lipid bioactive compounds, t suffers from less structural stability, poor water solubility and consequently less bioavailability and cellular uptake. Preparation of vitamin D microemulsions is one of the solutions for the above problems. Thus, in the present study, vitamin D microemulsions were prepared using various one/two-component stabilizer systems, namely, Tween 20 and sodium caseinate in various proportions. The effects of stabilizer components proportions on characteristics of gained vitamin D microemulsions were evaluated using a two-component mixture design of experiment. Therefore, various polynomial models were proposed in order to predict the characteristics of produced microemulsions. According to the optimization analysis, the vitamin D microemulsions stabilized by a stabilizer system composed of 70% Tween 20 and 30% sodium caseinate could produce the most desirable microemulsions with minimum mean particle size, polydispersity, and maximum zeta potential, transparency and vitamin D content. The produced vitamin D microemulsions showed acceptable chemical and good physical stabilities, which can be incorporated easily in water-based food and pharmaceutical formulations.


2019 ◽  
Vol 233 (10) ◽  
pp. 1485-1502 ◽  
Author(s):  
Zahra Sayyar ◽  
Hoda Jafarizadeh Malmiri

Abstract Curcumin as a lipophilic bioactive compound can be incorporated into water-based formulations when it turns into curcumin nanodispersions. In fact, nanodispersion systems, increase curcumin bioavailability, solubility and stability, and furthermore increase curcumin uses in aqueous food and pharmaceutical formulations. Present study focuses on the preparation of curcumin nanodispersions under subcritical water conditions (temperature of 120 °C and pressure of 1.5 bar for 2 h) and using selected another two different methods namely, spontaneous emulsification and solvent displacement. Lecithin as carrier oil, Tween 80 as emulsifier and polyethylene glycol as co-surfactant, with a ratio of 1:8:1, were used in all the preparation techniques. Obtained results indicated that curcumin nanodispersions with smallest mean particle size (70 nm), polydispersity index (0.57), curcumin loss (5.5%) and turbidity (0.04 Nephelometric Turbidity Unit), and maximum loading ability (0.189 g/L), loading efficiency (94.5%) and conductivity (0.157 mS/cm) were obtained under subcritical water conditions. The results also exhibited that the prepared spherical curcumin nanoparticles in the water by this technique had desirable physical stability as their mean zeta potential value was (−12.6 mV). It also observed that, as compared to spontaneous emulsification and solvent displacement methods, the prepared curcumin nanodispersions via subcritical water method had highest anti-oxidant and antibacterial activities.


2018 ◽  
Vol 10 (2) ◽  
pp. 20 ◽  
Author(s):  
Noor Mohammed Dawood ◽  
Shaimaa Nazar Abdal-hammid ◽  
Ahmed Abbas Hussien

Objective: The objective of this study was to prepare nanosuspension of a practical water insoluble antiulcer drug which is lafutidine to enhance the solubility, dissolution rate with studying the effect of different formulation variables to obtain the best formula with appropriate physical properties and higher dissolution rate.Methods: Nanosuspension of lafutidine was prepared using solvent anti-solvent precipitation method using Polyvinylpyrrolidone K-90(PVP K-90) as the stabilizer. Ten formulations were prepared to show the effect of different variables in which two formulations showed the effect of stabilizer type, three formulations showed the effect of stabilizer concentration, two formulations showed the effect of combination of polymer with surfactant such as tween 80, three formulations show the effect of stirring speed and three formulations prepare to show the effect of addition of co-surfactant such as tween 20. All these formulations are evaluated for their particle size and entrapment efficiency and in vitro release. The selected one was evaluated for zeta potential, scanning electron microscope, atomic force microscopy, Fourier transforms infrared spectroscopy, differential scanning calorimetry, saturation solubility and stability study.Results: The formulations (F3-F10) were in the nano size. The optimum concentration of the stabilizer was in the formulation when the drug: polymer: surfactant ratio 1:4:4 and the optimum stirring speed was 1500 rpm. Dramatic effect on the particle size reduction was found by the addition of co-surfactant (tween 20) in formulation F7 that has a particle size 15.89±1.8 nm. The selected formula F7 showed an enhanced dissolution profile (10 min) compared to the pure drug at all-time intervals.Conclusion: The results show that the formulation that contains drug: PVP-K90: tween 80: tween 20 in ratio 1:4:2:2 is the best one and can be utilized to formulate lafutidine nanosuspension. 


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Deryl Nii Okantey Kuevi ◽  
Noble Kuntworbe ◽  
Enoch Ayertey

Dispersed systems such as emulsions are easily destabilised during processing and storage since they are thermodynamically unstable systems. It is for this reason emulsifiers/stabilisers are frequently employed in pharmaceutical emulsion formulations to increase their short- and long-term kinetic stability. This current study seeks to investigate the potential emulsifying property of gums obtained from Khaya senegalensis (family: Meliaceae) trees. Gums were collected, authenticated, oven-dried, milled, filtered, and purified using 96% ethanol. The microbial quality of the gum was assessed following the BP (2013) specifications. The purified gum was free from some selected pathogenic microorganisms, rendering the gum safe for consumption. The emulsifying property was investigated by formulating emulsions using castor oil and employing the dry gum method. The ratios of oil-to-water-to-gum for the formulation of a stable emulsion were determined. The stability of the emulsion was evaluated, and an effort was made to improve the stability by incorporating Tween 80, hydroxypropyl methylcellulose, and xanthan gum. From the results, it can be inferred that Tween 80 (0.5%) was able to stabilise the emulsion. Addition of xanthan gum worsened the creaming. The effects of pH (4.0, 5.5, 7.2, 9.0, and 11.0) and electrolytes (0.1 M of NaCl, KCl, and CaCl2) on the physical stability of oil-in-water emulsions were studied during 12 weeks of storage. Percentage creaming volume and whether there was phase inversion were the criteria used as the evaluation parameter. From the percentage creaming volume data, emulsions formulated with both gums showed the lowest creaming volumes at pH of 7.2, followed by the acidic regions (pH 4.0, 5.5), with the basic regions (pH 9.0, 11.0) recording the highest creaming volumes. The effects of the various electrolytes at a constant concentration of 0.1 M on the o/w emulsions were found in this order NaCl < KCl < CaCl2. This study proves that Khaya senegalensis gum can successfully be employed as an emulsifying agent in pharmaceutical formulations.


Author(s):  
SARAH LABIB ◽  
MOHAMED NASR ◽  
MOHAMED NASR

Objective: The main objective of this study was to develop atorvastatin calcium (ATR) as an oral drug delivery system for a P-glycoprotein (P-gp) substrate drug using different pharmaceutical excipients that inhibit P-glycoprotein and evaluate the influence of nanocrystals on the dissolution characteristics and bioavailability compared to the plain drug. Methods: A nanosuspension was prepared by Solvent-antisolvent precipitation method using a solvent containing stabilizer that act as a p-gp inhibitor dissolved in distilled water as polyethylene glycol 300, polyethylene glycol 400 (PEG 300, PEG 400), tween 20 and tween 80 while the solvent selected for atorvastatin calcium was methanol. The concentrations were as follows: PEG 300 and 400 = 0.25% w/v, tween 20 and 80 = 0.75% v/v. Nanocrystals were extracted from the suspension and characterized. Results: Particle size of the drug was 1307±127.79 nm while the formulas prepared ranged from 223±17.67 to 887±58.12 nm. Pure ATR had a saturated solubility of 0.059±0.005 mg/ml and the prepared nanocrystals ranged from 0.32±0.021 to 0.88±0.019 mg/ml. The Percentage of drug released of plain atorvastatin calcium reached 41.49% while the formula ranged from 44.32 to 61.5%. Both XRD and SEM discussed the degree of crystallinity as follows: F1<F2<F4<F3<ATR. Conclusion: 0.3% of PEG 300 and PEG 400 were not enough to formulate proper nanocrystals while 0.75% tween 20 and tween 80 achieved acceptable formulas. F4 which is prepared with tween 80 exhibited the highest enhancement in saturated solubility, dissolution rate and subsequently expected to have improved oral bioavailability.


Author(s):  
ABEER A. EL-HADI ◽  
HANAN MOSTAFA AHMED ◽  
RANIA A. ZAKI ◽  
AMIRA MOHAMED MOHSEN

Objective: L-asparaginase (L-asp) is a vital enzyme used as a therapeutic agent in combination with other drugs in the treatment of acute lymphoma, melanosarcoma and lymphocytic leukemia. Immobilization of enzymes through loading on nanoemulsion (NE) results in some advantages such as enhancing their stability and increasing their resistance to proteases. Aim of the present study is to formulate L-asp loaded nanoemulsion to enhance its efficiency and thermal stability. Methods: Nanoemulsion loaded with L-asp crude extract (specific activity 13.23U/mg protein) was prepared employing oleic acid as oil, tween 20/tween 80 as surfactants and propylene glycol (PG) as co-surfactant. L-asp loaded NE underwent several thermodynamic stability studies and the optimized formulae were further examined for their biochemical properties and thermal stability. Results The developed formulations were spherical in shape and their sizes were in the nanometric dimensions with negatively charged zeta potential values. Upon comparing the enzyme activity of L-asp loaded NE employing tween 20 (F1) or tween80 (F4) at different concentrations, the results revealed that F4 NE showed higher enzymatic activity [323 U/ml] compared to F1 NE [197 U/ml] at the same concentration. The nanosized immobilized L-asp was more stable in the pH range from 8 to 8.5 as compared to free L-asp. The immobilized enzyme preserved about 59.11% of its residual activity at 50 °C; while free L-asp preserved about 33.84%. Conclusion: In the view of these results, NE composed of oleic acid, tween 80 and PG represents a promising dosage form for enhancing the activity and stability of Streptomyces griseoplanus L-asp.


2001 ◽  
Vol 15 (4-6) ◽  
pp. 513-519 ◽  
Author(s):  
Y. Hemar ◽  
M. Tamehana ◽  
P.A. Munro ◽  
H. Singh

Author(s):  
Nurhabibah Nurhabibah ◽  
A.K. Nugroho ◽  
Ronny Martien ◽  
Endang Lukitaningsih

This study aimed to determine the solubility of lovastatin (LV) in different oil, surfactant, and co-surfactant using the high-performance liquid chromatography method. LV was solubility studies in different vehicle. The different vehicle used almond oil, sunflower oil, oleic acid, olive oil, soybean oil, and corn oil, isoprophyl myristate, myoglyol, tween 80, tween 20, and cremophor R.H. 40, propylene glycol, and PEG 400. Each of them was added lovastatin until saturated. The mixtures were mixing, sonicating, putting in the water bath and standing for 24 hours, then centrifugated. Each of the aliquot 2 µL diluted with acetonitrile and determination of concentration lovastatin using HPLC, with detector ultraviolet at 237 nm. Before determinate LV validated, and curve calibration at range 2-16 µg/mL was made. This study using the HPLC method with detector UV 237 nm, Agilent C 18 (4.6 x 150 mm 5 µ) column, and acetonitrile: water (70:30 v/v) as mobile phase. Calibration curve of lovastatin at the range 2-16 µg/mL with linear regression 0.999. Accuracy and precision showed that. Lovastatin has high soluble in oleic acid, tween 80, and PEG 400.


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