Chemical Properties
Colorless, transparent liquid. Boiling point: 78°C (0.133 kPa).
Uses
Enbucrilate is bacteriostatic and its use is usually painless. It is used as an adhesive for lacerations of the skin, and in the treatment of bleeding from vascular structures.
Definition
ChEBI: Enbucrilate is a nitrile and an alpha,beta-unsaturated monocarboxylic acid.
Clinical Use
Enbucrilate injection of esophageal varices was first reported by Gotlib and Zimmermann in 1984 and has since been used in the acute treatment of bleeding esophageal varices in a few series, including randomized trials against band ligation for acute bleeding and for eradication of high-risk varices. Enbucrilate is often combined with lipiodol (lipid-soluble ethiodized oil) for injection of bleeding gastrointestinal ulcers; the advantage of this combination is slower polymerization of enbucrilate, with more accurate administration of the glue, but a potential disadvantage is a higher frequency of embolism, several cases of which have been reported. Overall, control of bleeding by using enbucrilate was found to be similar to band ligation, but rebleeding rates were higher. In addition, glue injection was found to be associated with sinus and fistula formation, in one case resulting in catastrophic bleeding. The higher complication rate may be explained by an increased risk of extravascular injection and attendant histotoxic reactions owing to the smaller lumen diameter.
Synthesis
The general procedure for the synthesis of embutane from formaldehyde and n-butyl cyanoacetate is as follows: 400 g of n-butyl cyanoacetate and an aqueous solution of paraformaldehyde or formaldehyde were added to a reactor, followed by 5 g of triphenylphosphine and 10 g of 1,5,7-triazacyclo[5.5.0]dec-5-ene. The mixture was stirred thoroughly and the reactor pressure was maintained below 30 mmHg using a control device. The reactor temperature was increased from room temperature to 60-65°C at a ramp rate of 1-1.5°C/min for 30 minutes for the condensation reaction. Next, the temperature was raised to 70-75°C at the same rate for 15 minutes for the reaction, and then the temperature was continued to 80-85°C and held for 15 minutes. The molar ratio of n-butyl cyanoacetate to formaldehyde was controlled at 1.05:1. After completion of the reaction, hot air was blown at 50 °C for 1 h to dry the reaction mixture, which was followed by treatment at 70 °C and 3 mmHg for 10 min to remove water completely. After dehydration, 5 g of phosphorus pentoxide and 5 g of hydroquinone were added and a vacuum of 3 mmHg was maintained while the reactor temperature was increased from room temperature to 120-130 °C at a rate of 1-1.5 °C/min for 15 min for the condensation reaction. The temperature was continued to be raised to 150-170 °C at the same rate and maintained for 15 min, and finally raised to 190-220 °C for 30 min to obtain crude α-cyanoacrylic acid n-butyl ester. The crude product was distilled by rapidly increasing the temperature, applying vacuum and collecting the fractions to obtain a distillation product with 95.3% yield and 98.6% GC purity.
in vivo
Enbucrilate offers an important intervention in gastric variceal bleeding which should be further studied in the US. A randomized trial is warranted to compare this intervention to radiological therapy[1]. The tissue adhesive Enbucrilate seems to be a safe, efficient agent to obtain good results in a simple, quick approach in the surgical treatment of symptomatic nephroptosis[2].
References
[1] Patent: CN107954901, 2018, A. Location in patent: Paragraph 0038-0043; 0046-0051
[2] Molecules, 2014, vol. 19, # 5, p. 6220 - 6227
[3] Patent: WO2018/114464, 2018, A1. Location in patent: Paragraph 0065
