Effect of combination of ultrasonic treatment and anti-solvent methods as a high-efficiency method of nanoparticle production on the tragacanth gum properties.

Gum tragacanth nanoparticles were prepared using a combination of intense ultrasound energy and anti-solvent precipitation methods in this research. Results showed that smaller particles were produced by increasing sonication time. As well, increasing the sonication power led to smaller particles, however, increased aggregation. Accordingly, tragacanth solutions with 0.5 and 1% (w/v) concentrations were prepared and mixed with ethanol (ratio 1:10 v/v) after ultrasound treatment with two different drop-wise and direct methods to investigate the effect of anti-solvent addition method on the precipitation of tragacanth particles. The nanoparticle images showed that the concentration of the 0.5% tragacanth solution and the direct mixing method was suitable for particle production with desirable size (72 ± 10 nm) and uniformity. FTIR, XRD, and STA studies showed that the tragacanth chemical composition did not change, and only its particle size decreased. Investigation of wettability showed a contact angle of 88.9 ± 1.7 degrees for nanoparticles providing partial wetting of the particles at the interface. Investigation of the solution viscosities of 0.5% tragacanth gum and tragacanth nanoparticles showed that the viscosity of the nanoparticles solution was significantly lower than that of the tragacanth (p < 0.05) indicating the intense effect of ultrasonication on this property. It can be concluded that the high viscosity of tragacanth gum is not due to its chemical composition but is due to its complex structure.

Stabilization of Pickering emulsion using tragacanth nanoparticles produced by a combination of ultrasonic and anti-solvent methods.

BACKGROUND: Because of the high surface/volume ratio in nanometric size particles, they exhibit novel functional properties in many industries, such as emulsion stabilization. Tragacanth nanoparticles (TNPs) were prepared in this research, applying intense ultrasound energy followed by anti-solvent precipitation in ethanol. RESULTS: Investigation of wettability showed a contact angle of 88.9 ± 1.7° for TNPs, providing partial wetting of the nanoparticles at the oil-water interface. Pickering emulsions were prepared using TNPs at different oil contents. Also, emulsions containing tragacanth gum solution were prepared as control emulsions. Results showed that the viscosity of the emulsions prepared by the TNPs was significantly lower than those of the control emulsions. Microscopic images showed that the size of the emulsion droplets decreased by increasing the nanoparticle concentrations. Evaluation of the stability of the emulsions showed that changes in the average diameter of the emulsion droplets stabilized by nanoparticles were not significant after 1 month of storage at room temperature. In contrast, the size of the droplet of control emulsions increased over the 30 days of storage. Thermal and mechanical stresses confirmed the effect of the concentration of TNPs and the oil ratio on the stability of the emulsions. CONCLUSION: The use of TNPs as a natural biopolymer is a promising approach in emulsion systems to prevent coalescence and increase the stability of the Pickering emulsions. © 2021 Society of Chemical Industry.

A Novel Therapy for cocaine dependence during abstinence: A randomized clinical trial.

BACKGROUND: Topiramate is an anticonvulsant drug and an ideal candidate for reducing the craving in people relying on cocaine. Contingency management is one of the common therapies in the domain of addiction. OBJECTIVE: The present study aimed to evaluate and compare three medication methods of Topiramate (TPM), Contingency Management (CM) and the combined TPM treatment and cash intervention on craving during abstinence. METHODS: This randomized clinical trial was conducted at Bijan Center for Substance Abuse Treatment in Tehran, Iran, from December 15, 2014 to November 20, 2015. One hundred males (Age range=18-34; SD=4.11) undergoing abstinence were assigned randomly to four groups (n=25) of Topiramate (TPM), Contingency Management (CM) and the Combined Method plus a placebo control group. Treatment was provided for twelve weeks for the experiment groups, and only the control group received the placebo. Participants in the Cash-based and CM Condition had an identical 12-week escalating schedule of reinforcement (cash-based incentives worth $0, $20, $40, and $80). Also, in the Topiramate group, participants' dosage ranged between 25-300 mg/day in escalating doses) 25, 50, 100, 150, 200, 250, 300). In addition, all subjects received brief behavioral compliance enhancement treatment (BBCET). Participants took a urine test twice a week, with a given threshold of > 300 ng/ml, and indicators of cocaine craving (response rate= 91%) was evaluated in two phases of pre-test and post-test. We used Chi square, ANCOVA Univariate Model and Scheffe's post hoc to analyze the primary and secondary outcomes. Also, the qualitative data resulted from demographic evaluations were coded and analyzed by the instrument of analysis of qualitative data i.e. Atlas.ti, Version 5.2. RESULTS: The results showed that all three types of treatment played a significant efficacy in reducing the craving. The mean (95% CI) scores of craving was 12.04 (p=0.05) with TPM, 13.89 (p=0.05) with CM, 10.92 (p=0.01) with Mix and 16.89 (p>0.05) with control. Moreover, the highest variance explaining the changes in craving was assigned to the combined treatment (p<0.01). CONCLUSIONS: The findings of this study, while having applicable aspects in this domain, can be helpful in planning supplementary remedial procedures. TRIAL REGISTRATION: The trial was registered at the Thai Clinical Trial Registration Center with the TCR ID: TCTR20170112001. FUNDING: The authors received no financial support for the research, authorship, and/or publication of this article.