Studies On Preparation Of Frankincense-Myrrh Essential Oil Ethosomes And Its Release In Vitro

Frankincense and myrrh,as the "important medicine for trauma" of traditional Chinese medicine,have excellent effects of "promoting blood circulation,relieving pain,detumescence and generating muscle",the essential oils of both have been proved to have outstanding analgesic and anti-inflammatory effects.However,the chemical components of both are highly volatile and unstable in chemical properties.If users use or store them improperly,that will affect the effect.Based on the analgesic and anti-inflammatory effects of frankincense and myrrh essential oils,this study studied and prepared a frankincense-myrrh essential oil ethosome with good stability,permeability and sustained-release performance.Studied the preparation process,established a quality evaluation system and studied the drug release in vitro,in order to improve the problems of single form,volatile and unstable application of the two essential oils.It provided a reference for the further development of new sustained-release preparations with anti-inflammatory and analgesic effects of other compound drugs.First,gas chromatography-mass spectrometer was used to analyze the components and study the stability of frankincense essential oil and myrrh essential oil.The components α-pinene with the highest content in the mixed essential oil were selected as indicator to establish the standard curves of peak area of α-pinene and concentration of frankincense-myrrh essential oil.The methods for determination of frankincense-myrrh essential oil were established,the specificity,precision,stability and recovery were all reached the detection requirements.An ultrafiltration centrifugation method was used to separate free essential oils from ethosomes,and a method was established to determine the encapsulation efficiency of ethosomes according to the determination method of the mixed essential oil.Taking appearance properties,stability and encapsulation efficiency as indicators,the formulation and preparation process of frankincense-myrrh essential oil ethosomes were screened and optimized by single factor test and orthogonal test.Optimal formulation process was as follows: the concentration of ethanol was 40%,the amount of frankincense-myrrh essential oil was 0.5%,the amount of soybean lecithin was 4%,the amount of cholesterol was0.6%,the amount of Pellicer L-30 was 0.1%,the temperature was 35 ℃,the emulsification stirring speed was 700 rpm,the dropping speed was 1 m L/min,the stirring time after dropping was 20 min,the homogenization speed was 9000 rpm,and the homogenization time was 20 min.The average encapsulation efficiency of three batches of frankincense-myrrh essential oil ethosomes prepared by the optimal formulation process was 73.47%.The quality of three batches of frankincense-myrrh essential oil ethosomes prepared by the optimal formulation process was investigated by taking the appearance characteristics,particle morphology,particle size,Zeta potential,particle dispersion index,p H value and storage stability of the ethosomes were taken as indicators.The results showed that the main components of essential oil did not change significantly before and after ethosomes encapsulation,and the effective components were stable.The appearance of frankincensemyrrh essential oil ethosomes was light yellow,stable and homogeneous,with obvious opalescence.Transmission electron microscope showed that the shape was nearly spherical and uniform.The average particle size of ethosomes in three batches was 175.77 nm,the PDI was 0.197,and the Zeta potential was-33.6 m V.The p H value was 6.73,which was weakly acidic and closed to the p H value of normal skin.The ethosomes were suitable for storage at4 ℃ under light protection,with good storage stability.The cumulative release of frankincense-myrrh essential oil ethosomes in different release media was investigated by reverse dialysis method using α-pinene as indicator,and the drug in vitro release behavior was discussed by fitting the drug release kinetics equation.Compared with the frankincense-myrrh essential oil ethanol solution,the cumulative release curve of frankincense-myrrh essential oil ethosomes was relatively flat,and the cumulative release in4 hours was less than 50%,which proves that the ethosomes realized the slow and nonconstant release of the frankincense-myrrh essential oil.The results of drug release kinetics in vitro showed that the cumulative release amount fit the first-order equation best,and the release mechanism was mainly diffusion.In summary,a frankincense-myrrh essential oil ethosomes with stable formulation process was prepared.It had high encapsulation efficiency,stable physical and chemical properties and storage,and had sustained-release performance,which provided new ideas and references for the further study of anti-inflammatory and analgesic related sustained release preparations.