Effect of radix scutellariae microemulsion gel on chronic eczema in mice model / 中国临床药理学与治疗学

AIM: To prepare radix scutellariae microemulsion gel and investigate its therapeutic effect on chronic eczema based on the previous research of radix scutellariae self microemulsion. METHODS: The gel matrix and humectant were optimized by single factor method and response surface method to obtain the formula and preparation technique of the gel. The Franz diffusion cell method was used to evaluate the transdermal properties of microemulsion and microemulsion gel in vitro. By establishing a chronic eczema model in the mouse ear, the swelling degree, swelling inhibition rate, pathological changes and tumor necrosis factor α (TNF-α), Interleukin-1β (IL-1β) and interleukin - 6 (IL-6) of radix scutellariae microemulsion gel were measured, to investigate the therapeutic effect on chronic eczema in mice. RESULTS: The physical and chemical properties of radix scutellariae microemulsion gel were stable. Compared with microemulsion, the microemulsion gel had better transdermal performance. The cumulative transdermal amount of baicalein and wogonin, the main components of microemulsion gel, was 1.85 times and 2.77 times of that of microemulsion respectively. Moreover, the steady flow rate and permeability coefficient of microemulsion gel significantly increased, and the lag time significantly shortened. Pharmacodynamic study showed that compared with the model group, the radix scutellariae microemulsion gel could significantly reduce the ear swelling of mice (P<0.05), and the serum inflammatory factor TNF - α, IL-1β and IL-6 reduced content by over 37%. Compared with the radix scutellaria aqueous extract and aqueous extract gel, the treatment of chronic eczema was better. CONCLUSION: The preparation process of radix scutellaria microemulsion gel is feasible, with strong transdermal property, and a significant therapeutic effect on chronic eczema.

Preparation and brain targeting via nasal route of asenapine maleate microemulsion gel / 中国药师

Objective To prepare asenapine maleate microemulsion gel(ASPM-Emulgel)and evaluate its brain targeting by nasal administration.Methods The prescription composition and dosage of asenapine maleate microemulsion(ASPM-Emul)was determined according to the equilibrium solubility of asenapine maleate(ASPM)in different oils,emulsifiers,co-emulsifiers and the compatibility results of excipients,and ASPM-Emul was prepared into a gel with carbomer 940 as the gel matrix.The particle size distribution and microstructure of ASPM-Emul were investigated.The in vitro release rates and permeability in sheep nasal mucosa of ASPM-Emul and ASPM Emulgel were compared using the Franz diffusion cell method.The nasal ciliary toxicity of ASPM-Emulgel was investigated using the in vivo toad maxillary model method.Brain targeting of ASPM-Emulgel by nasal administration in rats was evaluated.Results According to the results of equilibrium solubility and compatibility,Maisine 35-1,Tween 80 and Transcutol P were selected as the oil phase,emulsifier and co-emulsifier of ASPM-Emul,respectively,with the ratio of 4 ∶ 4 ∶ 2.ASPM-Emul was a light blue semi-transparent microemulsion with a particle size of(73.6±7.4)nm.The microemulsion was regularly spherical and uniformly dispersed under transmission electron microscopy.The results of in vitro release and permeation showed that the release rate of ASPM-Emul was relatively fast,while the release rate of ASPM-Emulgel remained stable.However,the permeability of the two formulations in sheep nasal mucosa was basically similar.ASPM-Emul and ASPM-Emulgel showed no significant toxicity to nasal cilia of toad.Compared with the tail vein ASPM group,the drug content in the brain of ASPM-Emul and ASPM-Emulgel significantly increased after nasal administration,both exhibiting significant brain targeting,and the drug targeting efficiency(DTE)of ASPM-Emulgel was higher.Conclusion The preparation of ASPM into microemulsion gel can significantly improve the brain targeting after nasal administration,and is expected to improve the clinical therapeutic effect of ASPM.

Topical Delivery of Eberconazole Nitrate Loaded Microemulsion: Formulation, Design and Evaluation

The objective of the present research work was to develop microemulsion for the transdermal delivery of eberconazole nitrate (EBZ). Initially oil, surfactant and co-surfactant were selected based on their solubility and emulsification study respectively. Pseudo ternary phase diagram was constructed to optimize the surfactant-co surfactant (Smix) ratio. Eberconazole nitrate (EBZ) loaded microemulsion was optimized using central composite design (CCD) with amount of Capmul MCM (X1), tween 80 (X2) and Transcutol (X3) as independent variables along with cumulative amount of drug release (Q24) (Y1), flux (Jss) (Y2) and lag time (tL) (Y3) as dependent variables. Drug release study of all the design batches showed successfully increased permeation of drug which might be due to compositional characteristics of ME. The globule size of the optimized batch of EBZ loaded ME (153.6nm) confirms the micrometer size of the formulation. Zeta potential and polydispersity index (PDI) of optimized batch was found to be -30.5 mV and 0.253 respectively which proved stability and uniform distribution of dispersed systems respectively. The optimized batch of MEs has the pH value of 6.96 ±0.21 which indicate there is no chance of skin irritation. Further Morphological and structural examination of the optimized batch of EBZ loaded ME was done by transmission electron microscope (TEM) and images illustrated the spherical micelles with size range of 100 – 200 nm which evidently may support the high absorption and results into enhancement of drug permeation which may increase the therapeutic effect, decrease the dose frequency and improving the patience compliance for topical drug delivery.

Effect of Microemulsion on Content of Index Components in Different Phases of Zexietang Extract / 中国实验方剂学杂志

ObjectiveTo investigate the effect of microemulsion on the distribution of index components in different phases of Zexietang extract based on high performance liquid chromatography（HPLC） and phase separation process. MethodParticle size meter and transmission electron microscope were used to characterize the colloidal particles in blank microemulsion， aqueous extract of Zexietang and microemulsion extract of Zexietang. The phase separation process was established by high-speed centrifugation and dialysis， and based on this process， the aqueous extract and microemulsion extract of Zexietang were separated into the true solution phase， the colloidal phase and the precipitation phase， respectively. The contents of six components， including atractylenolide Ⅲ， atractylenolide Ⅱ， 23-acetyl alisol C， alisol A， alisol B and alisol B 23-acetate， were determined by HPLC with the mobile phase of water（A）-acetonitrile（B） for gradient elution（0-5 min， 40%-43%B； 5-20 min， 43%-45%B； 20-45 min. 45%-60%B； 45-75 min， 60%-80%B）. The solubility of the index components in water and microemulsion was determined by saturation solubility method. ResultThe colloidal particles in the aqueous extract， microemulsion extract and blank microemulsion were all spherical， and the particle size， polydispersity index（PDI） and Zeta potential of the colloidal particles were in the order of aqueous extract >microemulsion extract >blank microemulsion. The results of phase separation showed that the colloidal phase and the true solution phase could be completely separated by dialysis for 2.5 h， and the phase separation process was tested to be stable and feasible. Compared with the aqueous extract of Zexietang， the use of microemulsion as an extraction solvent could increase the contents of atractylenolide Ⅲ， 23-acetyl alisol C， atractylenolide Ⅱ ， alisol A， alisol B and alisol B 23-acetate by 3.75， 6.82， 35.47， 10.66， 35.41， 27.75-fold， and could increase the extraction efficiencies of the latter five constituents by 2.03， 1.15， 1.70， 6.43， 5.53 times. The solubility test showed that the microemulsion could significantly improve the solubility of atractylenolide Ⅱ， alisol A， alisol B and alisol B 23-acetate， but it had less effect on the solubility of atractylenolide Ⅲ and 23-acetyl alisol C. ConclusionMicroemulsion can improve the extraction efficiency and increase the distribution of the index components in the colloidal phase state of Zexietang to different degrees， providing a reference for the feasibility of microemulsion as an extraction solvent for traditional Chinese medicine.

Preparation of two tanshinone Ⅱ_A-astragaloside Ⅳ co-loaded nano-delivery systems and in vitro antitumor activity comparison / 中国中药杂志

This study screened excellent carriers for co-loading tanshinone Ⅱ_A(TSA) and astragaloside Ⅳ(As) to construct antitumor nano-drug delivery systems for TSA and As. TSA-As microemulsions(TSA-As-MEs) were prepared by water titration. TSA-As metal-organic framework(MOF) nano-delivery system was prepared by loading TSA and As in MOF by the hydrothermal method. Dynamic light scattering(DLS), transmission electron microscopy(TEM), and scanning electron microscopy(SEM) were used to characterize the physicochemical properties of the two preparations. Drug loading was determined by HPLC and the effects of the two preparations on the proliferation of vascular endothelial cells, T lymphocytes, and hepatocellular carcinoma cells were detected by the CCK-8 method. The results showed that the particle size, Zeta potential, and drug loading of TSA-As-MEs were(47.69±0.71) nm,(-14.70±0.49) mV, and(0.22±0.01)%, while those of TSA-As-MOF were(258.3±25.2) nm,(-42.30 ± 1.27) mV, and 15.35%±0.01%. TSA-As-MOF was superior to TSA-As-MEs in drug loading, which could inhibit the proliferation of bEnd.3 cells at a lower concentration and improve the proliferation ability of CTLL-2 cells significantly. Therefore, MOF was preferred as an excellent carrier for TSA and As co-loading.

Preparation and evaluation of sirolimus sustained release tablets based on mesoporous silicon loaded self-microemulsion / 药学学报

Sirolimus self-microemulsion-mesoporous silicon sustained release tablets were prepared in order to improve the dissolution of the insoluble drug sirolimus and reduce its side effects. Firstly, sirolimus self-microemulsion was prepared and cured with mesoporous silicon. Secondly, the suitable excipients were selected according to the appearance, hardness and in vitro release rate. The sustained-release tablets with hydroxypropyl methylcellulose (HPMC) as skeleton material were prepared by powder direct pressing method, and the formulation was optimized by central composite design-response surface method to investigate the drug release in vitro. Finally, the pharmacokinetics was carried out in beagle dogs using the commercial sirolimus tablets as references. The final formulation of sustained-release tablets is as follows: 162 mg of sirolimus self-microemulsion-mesoporous silica (1∶1, w/w), 80 mg of HPMC K4M and 80 mg of carboxymethyl starch sodium, the microcrystalline cellulose is 168 mg. The results of in vitro release test showed that the self-made sustained-release tablets released slowly within 12 h, which conformed to the Ritger-Peppas model. The in vivo test results showed that compared with the commercial sirolimus tablets, the Cmax of the sustained-release tablets decreased by 49.47%, the Tmax of the sustained-release tablets was prolonged by 5.1 times, and the relative bioavailability was 105.81%. Sirolimus self-microemulsion-mesoporous silicon sustained-release tablets have good sustained-release effects in vitro and in vivo, which provides a reference for the solubilization of other insoluble drugs and the research and development of sustained-release preparations. Animal experiments and welfare processes were reviewed and approved by the Animal Ethics Committee of the 900TH Hospital of the Joint Logistics support Force.

Preparation and quality evaluation of total flavonoids microemulsion of "Pueraria lobata-Hovenia dulcis" / 中国中药杂志

The effective components of flavonoids in the "Pueraria lobata-Hovenia dulcis" drug pair have low bioavailability in vivo due to their unstable characteristics. This study used microemulsions with amphoteric carrier properties to solve this problem. The study drew pseudo-ternary phase diagrams through titration compatibility experiments of the oil phase with emulsifiers and co-emulsifiers and screened the prescription composition of blank microemulsions. The study used average particle size and PDI as evaluation indicators, and the central composite design-response surface method(CCD-RSM) was used to optimize the prescription; high-dosage drug-loaded microemulsions were obtained, and their physicochemical properties, appearance, and stability were evaluated. The results showed that when ethyl butyrate was used as the oil phase, polysorbate 80(tween 80) as the surfactant, and anhydrous ethanol as the cosurfactant, the maximum microemulsion area was obtained. When the difference in results was small, K_(m )of 1∶4 was chosen to ensure the safety of the prescription. The prescription composition optimized by the CCD-RSM was ethyl butyrate(16.28%), tween 80(9.59%), and anhydrous ethanol(38.34%). When the dosage reached 3% of the system mass, the total flavonoid microemulsion prepared had a clear and transparent appearance, with average particle size, PDI, and potential of(74.25±1.58)nm, 0.277±0.043, and(-0.08±0.07) mV, respectively. The microemulsion was spherical and evenly distributed under transmission electron microscopy. The centrifugal stability and temperature stability were good, and there was no layering or demulsification phenomenon, which significantly improved the in vitro dissolution of total flavonoids.

Establishment of a quantitative method for GC analysis of polyoxyethylene (35) castor oil in microemulsion extracts / 中国中药杂志

With the continuous exploration of microemulsions as solvents for traditional Chinese medicine extraction, polyoxyethy-lene(35) castor oil(CrEL), a commonly used surfactant, is being utilized by researchers. However, the problem of detecting residues of this surfactant in microemulsion extracts has greatly hampered the further development of microemulsion solvents. Based on the chemical structures of the components in CrEL and the content determination method of castor oil in the 2020 edition of the Chinese Pharmacopoeia(Vol. Ⅳ), this study employed gas chromatography(GC) and single-factor experiments to optimize the preparation method of methyl ricinoleate from CrEL. The conversion coefficient between the two was validated, and the optimal sample preparation method was used to process microemulsion extracts of Zexie Decoction from three batches. The content of methyl ricinoleate generated was determined, and the content of CrEL in the microemulsion extracts of Zexie Decoction was calculated using the above conversion coefficient. The results showed that the optimal preparation method for CrEL was determined. Specifically, 10 mL of 1 mol·L~(-1) KOH-methanol solution was heated at 60 ℃ for 15 min in a water bath. Subsequently, 10 mL of boron trifluoride etherate-methanol(1∶3) solution was heated at 60 ℃ for 15 min in a water bath, followed by extraction with n-hexane twice. CrEL could stably produce 20.84% methyl ricinoleate. According to this conversion coefficient, the average mass concentration of CrEL in the three batches of Zexie Decoction microemulsion extracts was 11.94 mg·mL~(-1), which was not significantly different from the CrEL mass concentration of 11.57 mg·mL~(-1) during microemulsion formulation, indicating that the established content determination method of this study was highly accurate, sensitive, and repeatable. It can be used for subsequent research on microemulsion extracts of Zexie Decoction and provide a reference for quality control of other drug formulations containing CrEL.

Microemulsions Improve Topical Protoporphyrin IX (PpIX) Delivery for Photodynamic Therapy of Skin Cancer

Abstract We report here microemulsions (MEs) for topical delivery of protoporphyrin IX (PpIX) for Photodynamic Therapy (PDT) of skin cancers. Selected MEs consisting of Oil/Water (O/W) bicontinuous (BC) and Water/Oil (W/O) preparations were characterized as to pH, nanometric size, zeta potential, drug content, and viscosity. Sustained in vitro PpIX release was achieved from MEs 2A (O/W), 10B (BC) and 16B (W/O) through an artificial membrane for up to 24 h, characterizing MEs as drug delivery systems. None of these MEs showed permeation through the skin, demonstrating the required topical effect. After 4 h, in vitro retention of PpIX in the stratum corneum (SC) was higher from both ME 10B and control (PpIX at 60 µg/mL in PEG 300). However, in the Epidermis + Dermis ([Ep + D]), retention from ME 10B and ME 16B was ~40 times higher compared to control. Confocal Laser Scanning Microscopy (CLSM) showed higher fluorescence intensity in the SC for both control and ME 10B, whereas ME 10B fluorescence was higher in [Ep+D]. The results indicate that ME 10B is suitable for PpIX encapsulation, showing good characteristics and a localized effect for a potential delivery system for PDT-associated treatments of skin cancers.

Preformulation studies for the development of a microemulsion formulation from Ambrosia peruviana All, with anti-inflammatory effect

Abstract Natural products are considered an important source of the therapeutic arsenal currently available. Among these alternatives are the seeds of Ambrosia peruviana (altamisa), whose extract has shown an anti-inflammatory effect. The main objective of this work was to perform a preformulation study of Ambrosia peruviana seeds ethanolic extract, where the main factors that affect the physical, chemical, and pharmacological stability of the extract were evaluated, as well as a compatibility study by differential scanning calorimetry (DSC) analysis against different excipients. A dry extract was obtained by rotary evaporation of the seeds macerated with 96% ethanol. The anti-inflammatory activity was determined by measuring its effect on NO production in RAW 264.7 macrophages, stimulated with LPS. The results showed that the dry extract maintained its stability over time when stored at a temperature of 4 and 25ºC, demonstrating its biological activity, the content of phenolic compounds, and its physicochemical parameters remain practically invariable. However, when exposed to high temperatures (60 ºC) it was affected. The thermal analysis revelated that the behavior of most of the selected excipients and the dry extract was maintained, which indicates that it did not present incompatibilities, therefore they can be candidates for formulating a microemulsion.

Comparison of Microemulsion and Solvent Evaporation Technique for Solubility Enhancement of Amlodipine Besylate

@#Introduction: Amlodipine besylate is a calcium channel blocker indicated for hypertension and angina. It is described as slightly soluble in water and due to its limited solubility, it may result in poor bioavailability. The aim of this study is to enhance the solubility of amlodipine besylate using solvent evaporation method and microemulsion technique and to compare the two methods. Method: Solid dispersions (SD) of amlodipine besylate were developed by employing solvent evaporation method. PEG6000 was the polymer of choice and different drug:polymer ratios were used. Evaluation of the prepared SDs include solubility studies, dissolution studies and scanning electron microscopy (SEM). As for the microemulsion technique, microemulsions were prepared by phase titration method and the optimized microemulsion formulation was then characterized for solubility studies and dissolution studies. Results: SD3 with drug:polymer ratio of 1:4 achieved the highest solubility which was 96.97 mg/ml ± 0.92 whereas the solubility of the optimized microemulsion was found to be 112.54 mg/ml ± 0.92. In solvent evaporation method, as the drug:polymer ratio increases, the solubility and dissolution rate of SDs increases. Conclusion: The two methods had significantly enhance the solubility of amlodipine besylate however the microemulsion technique showed better solubility profile.

Comparative study on in vivo and in vitro permeability of Huoxue Zhitong gel patch and microemulsion gel / 中国中药杂志

This study aims to establish a method for determination of paeonol(Pae), eugenol(Eug), and piperine(Pip) content in receptor liquid and research on the permeability and pharmacokinetics of Huoxue Zhitong gel patch and microemulsion gel. The Franz diffusion experiment was conducted to assess the percutaneous permeability, and the microdialysis method was employed to assess pharmacokinetics of Huoxue Zhitong gel patch and microemulsion gel. The content of Pae, Eug, and Pip in receptor liquid in vitro and in vivo was determined by HPLC and UPLC-MS. The Q_n and J_(ss) of Pae, Eug, and Pip in the gel patch were significantly higher than those in the microemulsion gel, indicating that the drug release was faster in the gel patch. The C_(max), AUC_(0-760), and MRT of Pae, Eug, and Pip in the gel patch were higher than those in the microemulsion gel, indicating that the gel patch can promote the penetration and prolong the skin residence of the drug. The results of this study provide reference for improving the dosage form of Huoxue Zhitong patch.

Preparation of Angelica•Cinnamomum self•microemulsion drug delivery system based on the concept of “unifica- tion of drugs and excipients ” / 中国药房

OBJECTIVE To prepare Angelica•Cinnamomum（Angelica sinensis-Cinnamomum cassia ）self•microemulsion drug delivery system （AC•SMEDDS），and to optimize its formulation and characterize its preparation . METHODS Using Angelica• Cinnamomum mixed volatile oil as oil phase and model drug ，on the basis of selecting emulsifier and co -emulsifier and the optimization of their mass ratio range ，the formulation was optimized with central composite design •response surface methodology using the ratio of oil phase （Angelica•Cinnamomum mixed volatile oil ），mass ratio of emulsifier and co -emulsifier as factors ，the comprehensive score of volatile oil content ，particle size and emulsifying time as index . Morphology，particle size ，drug loading ， entrapped efficiency and stability of optimized AC•SMEDDS were characterized . RESULTS The optimum formulation of AC•SMEDDS contained the ratio of oil phase was 30%，and the mass ratio of emulsifier （EL•40）and co -emulsifier（ethanol）was 9∶1. Results of validation tests showed that the average particle size of AC•SMEDDS was （148.33±1.53）nm，and emulsifying time was （18.44±0.11）s. The comprehensive score was 0.68，relative deviation of which from the predicted value （0.70）was 2.86%. AC•SMEDDS prepared by optimal formulation was faint yellow ，uniform and transparent liquid ，and spherical particals with translucent edge were observed under transmission electron microscope . Calculated by ligustilide and cinnamaldehyde ，the drug loading was （7.58±0.03） and （4.17±0.01） mg/g，and entrapped efficiency was （93.25±0.01）% and （88.89±0.02）% ， respectively. No stratification or precipitation occurred after centrifugation at the speed of 10 000 r/min or placing within 7 （No.2019-0520） days at 4 and 25 ℃ . The contents of ligustilide and cinnamaldehyde were stable . Its particle size had no significant change after 50，100 and 200 times dilution by purified water . CONCLUTIONS AC•SMEDDS is prepared successfully and its formulation is optimized . The stability of the preparation is good .

New topical microemulsions of etofenamate as sufficient management of osteoarthritis

Abstract In this study, microemulsions containing etofenamate were prepared and evaluated as dermal delivery carriers. The developed microemulsions consist of oleic acid, Span 80, Tween 20, Cremophor EL, Transcutol and ethanol. The percentage of etofenamate loading in the microemulsions was 5% (w/w). The characterization of formulations included droplet size, zeta potential, pH, conductivity, PDI, refractive index and viscosity. Moreover, ex vivo penetration study was carried out using mice abdominal skin. The developed formulations were analyzed for their cytotoxicity via MTT assay and tested for their anti-inflammatory properties opposed to LPS-stimulated nitrite prοduction in RAW 264.7 cells. As ideal formulation, M2ETF, was chosen due to its greater permeation, lower penetration as well as higher anti-inflammatory

Compatibility and efficiency of preservatives in emulsive cosmetics containing high surfactant content

Abstract The objective of this study was to determine the influence of nonionic surfactants on the effectiveness of preservatives used in emulsions containing high surfactant content. Mixtures of different concentrations were prepared between polyethoxylated (40) hydrogenated castor oil (PHCO) and polyoxyethylene sorbitan monooleate (PSO), with methylparaben, phenoxyethanol, methylparaben, ethylparaben, propylparaben, and isobutylparaben (PMEPBI) blend, phenoxyethanol and benzoic acid (BP) blend, and phenoxyethanol and caprylyl glycol (PC) blend. Subsequently, the compatibility of the formulation ingredients and the effectiveness of the preservatives were evaluated by the challenge test. It was found that PHCO and PSO inactivated the antimicrobial action of methylparaben and PMEPBI. Paraben-free preservatives BP and PC had less influence on surfactants than systems containing parabens. When incorporated into microemulsions and nanoemulsions containing 40% and 20% surfactants, methylparaben and BP 0.2% and 0.5% were only effective against Aspergillus niger. The PMEPBI 0.2% was effective as a preservative in nanoemulsified formulations against A. niger, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The results demonstrate that the efficacy of the preservative system in formulations containing nonionic surfactant excipients depends on the type of excipient, the components of the formulation, the preservative systems composition, the excipient to preservative ratio, and the availability in the formulation.

Semisolid formulations based on solid-in-oil-in-water systems containing proteins

Abstract In recent years, improvements have been made, through biotechnological processes, in the production and development of peptides capable of increasing collagen and elastin synthesis for anti-aging skin care. However, proteins have many limitations due to their structural, chemical and physical fragility to external aggressions, which may cause conformational changes, leading to loss of biological activity. Therefore, it is important to create delivery systems that protect these biomolecules from damage, allowing them to reach their target. This work aimed to develop a system able to carry bovine serum albumin (BSA), used as a model of a protein, and to incorporate this system in a semisolid formulation suitable for skin application. A microemulgel based on a solid-in-oil-in-water (S/O/W) microemulsion was prepared. Firstly, the association efficiency (AE) of lyophilized BSA-sucrose ester complex and the size of S/O nanodispersion were assessed; then, the characterization and stability evaluation of the final semisolid formulation through evaluation of pH, texture and rheological behavior were performed. The average value of AE was 54.74% ± 2.17. It was possible to develop an S/O/W microemulsion, which allowed the subsequent development of an S/O/W microemulgel that assured suitable pH, texture and rheological characteristics for skin application.

Formulation and antimicrobial activity evaluation of a 0. 2% chlorhexidine canine mouthwash with essential oils / Formulación y evaluación de la actividad antimicrobiana de un enjuague bucal canino de clorhexidina al 2% y aceites esenciales

Background: Periodontal disease is the infection and inflammation of the gums, bones, and tissues involved in teeth support, and it is one of the most common diseases affecting pet dogs. Essential oils have shown antimicrobial activity against bacteria causing periodontal disease; therefore, they are considered potential therapeutic agents. Objectives: The main objective was to formulate and evaluate the antimicrobial activity of a 0.2% chlorhexidine canine mouthwash with essential oils. Methods: Three microemulsion formulations were obtained by constructing a pseudo-ternary phase diagram using the phase titration method. Different surfactant agents were evaluated, and hydrogenated castor oil was selected as the emulsifier agent. The antimicrobial activity of oregano essential oil (Origanum vulgare), thyme essential oil (Thymus vulgaris), and the three formulations were evaluated against Staphylococcus aureus, Streptococcus mutans, Streptococcus salivarius, and Escherichia coli. Results: Pure thyme and oregano essential oils showed higher antimicrobial activity than a 0,2% chlorhexidine solution. The formulations with essential oils plus chlorhexidine and chlorhexidine alone showed antimicrobial activity. The formulation containing only essential oils did not show antimicrobial activity. Conclusions: A canine mouthwash was formulated with chlorhexidine and thyme, and oregano essential oil. Based on the evaluation of antimicrobial activity, two of the proposed formulations could be a therapeutic option to reduce the risk and prevent periodontal disease in canines

Antecedentes: La enfermedad periodontal es la infección e inflamación de las encías, huesos y tejidos que brindan soporte a los dientes, es una de las enfermedades más comunes que afectan a los perros de compañía. Los aceites esenciales han mostrado actividad antimicrobiana contra las bacterias que causan la enfermedad periodontal; por lo tanto, son considerados como potenciales agentes terapéuticos. Objetivos: El objetivo principal de este trabajo fue formular y evaluar la actividad antimicrobiana de un colutorio canino de clorhexidina al 0,2% con aceites esenciales. Métodos: Se obtuvo tres formulaciones en microemulsión mediante la construcción de un diagrama de fase pseudoternario por el método de titulación de fase. Se evaluaron diferentes tensioactivos y se seleccionó el aceite de ricino hidrogenado como agente emulsificante de la formulación. La actividad antimicrobiana del aceite esencial de orégano (Origanum vulgare), el aceite esencial de tomillo (Thymus vulgaris) y las tres formulaciones fue evaluada contra Staphylococcus aureus, Streptococcus mutans, Streptococcus salivarius y Escherichia coli. Resultados: Los aceites esenciales puros de tomillo y orégano mostraron una mayor actividad antimicrobiana que una solución de clorhexidina al 0,2%. Las formulaciones con aceites esenciales más clorhexidina y únicamente clorhexidina mostraron actividad antimicrobiana. Mientras que la formulación que contiene solo aceites esenciales no mostró actividad antimicrobiana. Conclusión: Se formuló un enjuague bucal canino con clorhexidina y aceite esencial de tomillo y orégano. Según la evaluación de la actividad antimicrobiana, dos de las formulaciones propuestas podrían ser una opción terapéutica para disminuir el riesgo y prevenir la enfermedad periodontal en caninos

Preparation and quality evaluation of fluorocarbon microemulsion-based gel loaded with both 5-aminolevulinic acid and carbon dioxide / 药学学报

To improve the efficacy of 5-aminolevulinic acid (5-ALA)-mediated photodynamic therapy (PDT), a fluorocarbon microemulsion-based gel (FMBG) loaded with both 5-ALA and carbon dioxide (CO2) was prepared in this study. Its physical and chemical properties such as particle size, zeta potential, morphology, pH value and viscosity were characterized. Acid-base titration experiment was used to determine the CO2 loading, a fluorescence derivatization method was established to determine the content of 5-ALA, and the confocal laser scanning microscope and Franz diffusion cell method were carried out to investigate its transdermal ability. Through the laser speckle contrast imaging, the CO2-affected blood flow perfusion of skin was measured. Finally, the skin irritation test was tested by hematoxylin-eosin staining (H&E) method. These results showed that the prepared FMBG was a milky white gel, with an average particle size of 202.4 nm, a zeta potential of -25.3 mV, a pH of 6.0, and a viscosity of 1 062.0 mPa·s. It can be stored stably for seven days at room temperature. The 5-ALA content of FMBG was measured to be approximately equal to 20% (w/w). At room temperature and normal pressure, the CO2 loading content of FMBG was 5.016 mg·L-1, which was 1.5 times as much as that of water. The transdermal absorption experiment and blood perfusion results showed that the FMBG can effectively enable the transdermal delivery of 5-ALA and CO2, and significantly increased the blood perfusion of skin. H&E staining results indicated that FMBG had negligible skin irritation (all animal tests were approved by the Ethics Committee of 900 Hospital of the Joint Logistics Team). In this study, a safe and stable FMBG loaded with both 5-ALA and CO2 was successfully prepared. It was suitable for transdermal application, having the potential of enhancing the efficacy of 5-ALA-mediated PDT.

Microemulsion assisted transdermal delivery of a hydrophilic anti-osteoporotic drug: Formulation, in vivo pharmacokinetic studies, in vitro cell osteogenic activity

Gastrointestinal adverse effects such as esophageal irritation and ulcers are the major disadvantages of the oraladministration of alendronate (ALD) and nitrogen-containing bisphosphonate. We hypothesized that the transdermaldelivery of ALD via water in oil (w/o) microemulsion might help to prevent the aforementioned side effects withoutcompromising the efficacy. The pseudo-ternary phase diagrams were constructed with varying ratios of surfactantmixture and oil to recognize the concentration range of excipients required to form a monophasic microemulsion.Globule size, morphology transmission electron microscopy, and thermal behavior differential scanning colorimetryof drug-loaded microemulsion were investigated. The in vitro permeation studies revealed significantly enhancedpermeation of ALD through microemulsion than pure solution across the rat skin (p < 0.01). In an in vivopharmacokinetic study in Wistar rats, microemulsion achieved around two folds higher bioavailability than pure drugsolution (p < 0.05) when given in equal doses (30 mg/kg). Cell viability assay with human osteoblastic osteosarcoma(MG-63) cells exhibited the positive effects of ALD microemulsion on cell growth. Moreover, alkaline phosphataseand mineralization studies proved that microemulsion as a carrier retains distinct osteogenic properties of ALD.Overall, these outcomes demonstrated that the w/o microemulsion as a transdermal carrier is a promising approach forthe effective delivery of ALD, bypassing the adverse effects associated with oral administration

Development And Validation Of A Simple Hplc Method For Estimation Of Mycophenolate Mofetil In Microemulsion Formulation

Objective: The present study deals with the development, validation and application of a simple, precise and accurate HPLC method for the determination of mycophenolate mofetil in pharmaceutical formulations and microemulsions. Methods: In this method, a simple isocratic mobile phase composition of methanol and water (75:25 v/v) pumped at 1 ml/minute flow rate through Phenomenex C18 column (dimension: 250 4.6 mm and 5 µm particle size) was used. Injection volume was 20 µl and analysis of mycophenolate mofetil was carried out at 250 nm. Results: The coefficient of regression was found to be 0.9996, indicating the linearity of the developed method within a range of 0.1 to 10 µg/ml. The limit of detection (LOD) and the limit of quantization (LOQ) were found to be 3.660ng/ml and 11.091ng/ml, respectively. The results showed that % deviation for change in compositions of the mobile phase, flow rate and temperature was within a range of-5.51 to 10.99%,-3.70 to 8.80% and-5.29 to 10.90%, respectively. The method seemed sensitive to change of temperature (±5 ○C) and methanol composition (±2%) as the results were at the boundary limit of 10% deviation. Conclusion: A simple, precise and accurate HPLC method for the determination of drug content from microemulsion has been developed and validated in accordance with ICH guidelines.