emulsified isoflurane

Emulsified isoflurane (EI) is a novel intravenous general anesthetic created by encapsulating isoflurane molecules into an emulsion. This innovative formulation transforms the traditionally inhaled volatile anesthetic into an injectable form, offering several advantages over conventional isoflurane administration. ## Description Emulsified isoflurane is a parenteral formulation of isoflurane, created by encapsulating isoflurane molecules within a lipid emulsion. The typical formulation consists of isoflurane encapsulated in particles composed of an isoflurane-soybean oil core with a lecithin shell[1]. This formulation allows for intravenous administration rather than the traditional inhalation route required for conventional isoflurane. The development of emulsified isoflurane addresses several limitations of inhaled isoflurane: 1. **Elimination of specialized equipment**: EI can be administered intravenously without requiring vaporizers or other specialized anesthesia equipment[1][3]. 2. **Reduced environmental impact**: Intravenous administration prevents air pollution in operating rooms that occurs with volatile anesthetics[1]. 3. **Faster induction**: EI avoids the need for lung uptake and the dilution effects of the respiratory circuit, resulting in more rapid onset of action[1]. 4. **Alternative elimination pathways**: EI is eliminated through multiple routes rather than primarily through the lungs[1]. Recent research has also identified potential therapeutic applications beyond general anesthesia, including treatment for organophosphate poisoning where EI has demonstrated anticonvulsant and neuroprotective properties[3][4]. ## Formulation and Stability The formulation of emulsified isoflurane has evolved over time. Early versions were created by stirring isoflurane in 30% emulsion with shearing and homogenization, resulting in 350 nm particles[1]. However, these particles could polymerize during sterilization, leading to breakdown and potential pulmonary capillary blockage[1]. Newer formulations have improved stability. A recent study demonstrated that emulsions of 15% vol/vol isoflurane with 10% Lipoid S75 prepared by ultrasonic sonication remained stable for at least 24 hours at room temperature (18-20°C) and maintained their volume for 290 days when refrigerated at 4°C[5]. ## Therapeutic Applications While primarily developed as an alternative method for delivering general anesthesia, emulsified isoflurane has shown promise in other therapeutic areas: 1. **Organophosphate poisoning treatment**: Research has demonstrated that intravenous isoflurane-lipid emulsion can effectively stop convulsions induced by organophosphate poisoning, providing a treatment option that doesn't require specialized vaporizer equipment[3][4]. 2. **Cellular protection**: Studies have shown that emulsified isoflurane has immunomodulating and anti-inflammatory effects in vital organs such as the brain and myocardium[5]. It has demonstrated protective effects against hypoxia in canine hepatocytes by reducing apoptosis[5]. The development of emulsified isoflurane represents an innovative approach to drug delivery that expands the utility of a well-established anesthetic agent while addressing its limitations.

Other names

EINFEIPFEI