Preparation And Evaluation Of Compound Essential Oil Microemulsion For Neck And Shoulder Pain

Neck and Shoulder Pain is pain in the neck,shoulders and scapula,which mainly originates from cervical spondylosis,frozen shoulder and other diseases.Neck and sh oulder pain is an extremely common pain and the risk of neck and shoulder pain incre ases with age,but in recent years there has been a trend towards a younger age group.Current treatment options for neck and shoulder pain include surgical and non-surgica l treatments.Most patients choose non-surgical treatment,which is mainly divided int o medication,tui-na manipulation,acupuncture and traction treatment.At present,ther e is no specific medicine for neck and shoulder pain,but the main clinical application is anti-inflammatory and analgesic drugs,such as aspirin,ibuprofen,diclofenac,etc.T hese drugs can effectively relieve pain,but long-term use has adverse effects on the ga strointestinal tract,cardiovascular system,nervous system,liver,blood system,kidney s,etc.,and the dose of medication increases with the increase of pain.Essential oil is an aromatic ingredient extracted from Chinese herbs,which is vol atile and insoluble in water,with high permeability,strong biological activity and low toxic side effects.Essential oils are rich in a variety of chemical components,and ther efore have the efficacy of relieving symptoms,promoting qi,opening the orifices,and resolving dampness,as well as pharmacological activities such as antibacterial,antivi ral,analgesic,anti-inflammatory,and antioxidant,and are widely used in the preventio n and rehabilitation of many diseases.In this paper,we will conduct a study on the tre atment of neck and shoulder pain with essential oils from Chinese medicine,specifical ly from the extraction process of essential oils,the network pharmacology of compoun d essential oils on neck and shoulder pain,the preparation and optimization of microe mulsion formulations of essential oils and the investigation of transdermal absorption of microemulsion formulations.The investigation of their chemical composition primarily hinges on the extractio n technology.Traditional techniques for extraction encompass steam distillation,solve nt extraction,pressing,and absorption,alongside novel methods such as supercritical f luid extraction,enzyme extraction,microwave-assisted extraction,solid-phase microe xtraction,and subcritical water extraction.Each method boasts its own advantages,dr awbacks,and fields of application.With comprehensive considerations and an apprais al of the current research status,steam distillation remains the most frequently used m ethod for extraction and separation purposes.Based on experiments using hot plates an d xylene-induced ear swelling,researchers investigated the analgesic and anti-inflamm atory effects of essential oils to identify the most effective compound essential oil for t reating neck and shoulder pain.Seven essential oils were selected,including Artemisia argyi oil,Cinnamomum cassia oil,Boswellia carterii oil,Commiphora myrrha oil,Zin giber officinale oil,Ilex verticillata oil and Lavandula angustifolia oil,which were mix ed in a 1∶1 ratio to create the compound essential oil.The compound oil was extracte d through steam distillation,which involved extracting volatile oil by water distillatio n,steam distillation,and hydrodistillation after cutting and soaking the herbs in water.The extraction process was studied through a single-factor investigation of the ratio of material to liquid,soaking time,and distillation time of herbs and water.The best extr action process parameters were determined for each herb based on the extraction amou nt.Results showed that the best extraction processes for the seven essential oils were∶Artemisia argyi oil(ratio of material to liquid = 1∶6,soaking time = 1 h,distillation t ime = 5 h),Cinnamomum cassia oil(ratio of material to liquid = 1∶10,soaking time= 1h,distillation time = 4 h),Boswellia carterii oil(ratio of material to liquid = 1∶6,s oaking time = 4 h,distillation time = 3-4 h),Commiphora myrrha oil(ratio of material to liquid = 1∶6,soaking time = 3h,distillation time = 4h),Zingiber officinale oil(rat io of material to liquid = 1∶10,soaking time = 3h,distillation time = 4h),Ilex verticil lata oil(ratio of material to liquid = 1∶6,soaking time = 3h,distillation time = 4h),a nd Lavandula angustifolia oil(ratio of material to liquid = 1∶14,soaking time = 4h,d istillation time = 2h).The present study aimed to investigate the transdermal absorption ability of a co mplex essential oil nanoemulsion using the Franz diffusion cell method coupled with g as chromatography(GC)analysis.The objective was to establish a reliable detection m ethod for the main therapeutic effects of eucalyptus oil,borneol,and camphor,which were used as indicator components of the microemulsion system.Skin permeability an d retention of the nanoemulsion preparations were compared and analyzed with those of ordinary oil liquids.The findings revealed that the skin permeability and retention o f the nanoemulsion preparations were superior to those of the ordinary oil liquid of co mplex essential oil.Furthermore,the nanoemulsion of complex essential oil exhibited favorable penetrating and sustained-release properties.These results provide valuable insights into the potential applications of essential oil nanoemulsions in drug delivery and cosmetic formulations.The chemical composition of the extracted essential oils was identified through G C-MS analysis,and combined with network pharmacology to identify the main targets and pathways of the compound essential oil for treating neck and shoulder pain.69 co mponents were identified in the compound essential oil through GC-MS analysis,and77 core components were selected from literature.Network pharmacology analysis ide ntified 46 potential targets for pain relief,with 11 core targets being identified.KEGG analysis showed that the main pathways involved in treating neck and shoulder pain i ncluded chemical carcinogenesis-receptor activation,lipid and atherosclerosis,seroton in synaptic function,neuroactive ligand-receptor interaction,calcium signaling pathwa y,c GMP-PKG signaling pathway,IL-17 signaling pathway,inflammation modulation of TRP channels,acetylcholine synaptic function,arachidonic acid metabolism,cytoch rome P450 metabolism of xenobiotics,c AMP signaling pathway,and rheumatoid arthr itis.The various active ingredients in the compound essential oil can act on targets suc h as TPPV1,PTGS2,IL1 B,and TNF and have a therapeutic effect on neck and should er pain through multiple pathways.Nanoemulsions containing compound essential oil s were prepared using the spontaneous emulsification method.Various surface-active a gents and cosurfactants with different HLB and Km values were screened.The Box-B ehnken design-based response surface methodology was employed to optimize the for mulation,resulting in the following optimal prescription∶ 4% of the oil phase was ac counted for by the compound essential oil,10.7% of emulsifiers was a blend of Tw80 and RH40 at a ratio of 2∶1 serving as the surface-active agent,5.3% of the system w as anhydrous ethanol serving as the cosurfactant,and laboratory ultra-pure water made up 80% of the water phase.The physicochemical properties and stability of the nanoe mulsions were evaluated.The nanoemulsions of compound essential oils were observe d to be light yellow,clear,and transparent,with a particle size of 20.58 nm,p H of 6.13,electric conductivity of 439 μS/cm,and viscosity of 4.13±0.2 m Pa·s.Analysis of the centrifugal stability,thermal stability,and long-term storage stability through observat ion of appearance,color,and size indicated that these nanoemulsions exhibited good t hermodynamic stability.