Microemulsion Formulation Research Articles

Extraction and Microemulsion of Lupin Protein

In present study, protein and oil were extracted from sweet and bitter lupin that were used to define the phase behaviour of a three-component system (lupin oil, Tween 80/propylene glycol and water/lupin protein). Ternary phase diagrams were constructed and the optimum area of ternary phase diagrams corresponding to the formation of microemulsions were identified using emulsion titration method. Phase inversion composition method was applied, which involved the spontaneous formation of microemulsion, characterized by visual observation for their phase separation and optical clarity (e.g. transparency and opacity). Generally, o/w microemulsions were formed at a small region of the ternary phase diagrams with a relatively large ratio of water/lupin protein. Some differences between the sweet and bitter lupin diagrams were observed in regions, including bi- and multiphase, liquid crystals, gel and coarse emulsions. The physical characteristics of the microemulsions did not change with different storage temperatures.

Formulation and Evaluation of Self Micro-Emulsifying drug delivery System of Carvedilol

The current work involves preparation and evaluation of self-micro emulsifying drug delivery system of carvedilol, an nonselective betablocker and alpha-1 blocker. Oral self micro-emulsifying drug delivery system of Carvedilol were prepared by studying the solubility in different oils, surfactants and co-surfactants and formulations were prepared using mixtures of oils, surfactants, and cosurfactants in various proportions. Based on the solubility study, the optimised self micro-emulsifying drug delivery system of carvedilol was prepared using Capryol 90 as oil phase and tween 20 and transcutol P as surfactant and co-surfactant, respectively. The formulations were evaluated for stability, globule size and in vitro performance. To estimate the drug content from various excipients, final microemulsion formulations and in vitro performance study, a stability-indicating validated high-performance liquid chromatography method was developed using Inertsil ODS-3V (150 mm×4.6 mm, 5 μm) high-performance liquid chromatography column. The method was validated for various parametes like accuracy, linearity, precision (intraday and interday) and robustness. All the validation parameters were in acceptable range. The developed method was found to be specific accurate and robust for estimation of carvedilol from its microemulsion formulations.

Surfactant flooding for enhanced oil recovery – Insights on oil solubilization through optical spectroscopic approach

Surfactant flooding is a proven method employed to improve the recovery of crude oil from subsurface reservoirs but the knowledge about microemulsion formation, factors related to their stability, and the trapping mechanism of crude oil components in a microemulsion is still not clear for designing of injection fluid for specific crude type. The interaction mechanisms of four crude oils with surfactant-brine solutions were studied in this work for better insight into the molecular level mechanisms during surfactant flooding. UV–visible absorption and fluorescence spectra of the separated maltene and asphaltene fractions indicate the structural difference of the components in the molecular level, particularly, the size of the fused aromatic rings (FAR) present within individual bulk crude sample. Moreover, the FTIR spectra of the separated asphaltenes from the crude samples clearly showed the subtle difference in the functional groups present in respective FAR structures. Well-characterized compositionally different crude oils were mixed with four different surfactant-brine solutions (anionic – SDS, AOS, cationic - CTAB, and neutral - TX-100) and examined using UV–visible absorption and fluorescence spectroscopic approach. Detailed analysis of the acquired absorption and fluorescence spectra of the crude oil-surfactant-brine solutions distinctly demonstrate the entrapment of different crude oil components within the micelles formed by surfactants of different charges while the synchronous fluorescence spectra show the entrapment of specific size FARs within the specific micellar microenvironment. The results exhibit that the anionic surfactant entraps the smaller size (2–4) FARs whereas cationic and neutral surfactants entrap small as well as medium size (2–6) FARs within the formed micelles in the microemulsions. The present spectroscopic study signifies the importance of molecular-level interaction mechanisms for customized designing of surfactant solutions for maximizing crude oil recovery from petroleum reservoirs.

Formulation of virgin coconut oil microemulsion with natural excipients

Introduction: Virgin coconut (Cocos nucifera (L.)) oil (VCO) is taking attention from re-searchers because of its biological activities. However, applying VCO directly on the skin often leaves an uncomfortable feeling of greasy, clogged pores and difficult to wash. Coco-nut oil in microemulsion is a better option since it can increase bioavailability as well as convenience for users. Furthermore, this study aims to use natural ingredients, safe for the skin and environmentally friendly. Methods: The research started from extracting saponins from Gleditsia australis by using ethanol and water as extraction solvents. The extracted saponins were characterized by chemical reactions. Then we combined saponins and some other surfactants to investigate the possibility of microemulsion formation. Results: We extracted saponins with efficiency of 7.2%. The results showed that microemul-sions were formed using a mixture of surfactants including saponins and lecithin (ratio of 0.05:100 w:w) in the formula with a ratio of water phase, oil phase, surfactants respectively 3%, 48.5%, 48.5%. Microemulsion met the requirements of quality control and the product is microbiologically stable after 3 months of storage without using preservatives. Conclusion: In this study, we have successfully prepared Virgin coconut oil microemulsion using natural excipients including Virgin coconut oil, water and a mixture of surfactants used as saponins and lecithin. The system showed stability at 30 and 40 °C upon three-month storage and the product is microbiologically stable after 3 months of storage without using preservatives.

Synergistic antifungal potential of fluconazole-based cardamom oil oral microemulsion formulation against C. albicans

Synergistic antifungal potential of fluconazole-based cardamom oil oral microemulsion formulation against C. albicans

Efficacy of a new combination of a microemulsion and oral supplementation for androgenetic alopecia: an interventional multicentric study.

The aim of this study was to study new therapeutic options for the treatment of female and male androgenetic alopecia (AGA) and to assess the efficacy of a possible new coadjuvant oral and topical therapy, containing a complex of natural substances. Sixty individuals affected by mild-to-moderate female and male AGA were enrolled in the study and underwent the oral and topical treatment with a microemulsion formulation for 6 months. At baseline and at 3- and 6-month follow-up, global photographs were taken and three expert operators evaluated photographs using the 7-point scale. On a subgroup of our sample, non-invasive phototrichograms with TrichoScan® HD at baseline and follow-ups were performed to collect the trichological parameters of total number of hairs, hair density/cm2, vellus hair density/cm2, terminal hair density/cm2 and hair thickness. One-way ANOVA and Unpaired Student t-test were performed to analyze the data. Using the 7-point scale, a clinically visible improvement of hair loss was observed after three and six months of treatment. A statistically significant increase of all TrichoScan® trichological parameters was observed at both 3- and 6 month-follow-up. The complex of natural and active substances tested in this work showed good efficacy in improving both male and female hair loss. These new products could represent a valid alternative or coadjuvant therapy of AGA, increasing the efficacy of conventional treatments such as minoxidil or finasteride.

Design of microemulsion formulations loaded Scutellaria salviifolia Benth, Sideritis libanotica Labill. subsp. linearis (Bentham) Bornm, and Ziziphora clinopodioides Lam. extracts from Turkey and in vitro evaluation of their biological activities

The species belonging to the Lamiaceae family have been useful tools for many years as a folk remedy. In the present study, a microemulsion system was developed with extract of Scutellaria salviifolia Benth (endemic), Sideritis libanotica Labill. subsp. linearis (Bentham) Bornm (endemic), and Ziziphora clinopodioides Lam. Both and related microemulsion formulations were also investigated for their potential biological activities. Pseudo-ternary phase diagrams of formulations were constructed consisting of oil/ mixed surfactant/water emulsion system and a quaternary component. Antioxidant activity was determined by using 1,1-diphenyl-2- picrylhydrazyl (DPPH) free radical scavenging method. For antimicrobial activity determination, on the other hand, microdilution method was performed with Escherichia coli 25922, Staphylococcus aureus 29213, Candida albicans 14053, and Candida krusei 6258 standard strains. Tested extracts showed S. aureus-specific antibacterial activity with MIC values 64 µg/mL, 256 µg/mL, and 512 µg/mL for S. libanotica subsp. linearis, S. salviifolia, and Z. clinopodioides, respectively. For any other tested strain, considerable antimicrobial activity was not observed (MIC values > 1024 µg/mL). Related formulations were not superior to extracts in terms of antimicrobial activity. All extracts and related formulations appear to have antioxidant activity, and the antioxidant capacity of all formulations is higher than the extracts. When compared to ascorbic acid, formulation of S. libanotica subsp. linearis extract has stronger antioxidant activity. Sideritis libanotica subsp. linearis extract had a remarkable antibacterial activity against S. aureus. It also had a stronger antioxidant capacity than ascorbic acid. Besides, all formulations developed from extracts had antioxidant activity enhancing properties, although they did not contribute to antimicrobial activity. In conclusion, considering the potential antiinflammatory activity due to antioxidant activity, it is predicted that especially the formulation developed with Sideritis libanotica subsp. linearis extract is worth exploring with further studies for topical treatment of S. aureus-infected wounds and burns.

Study and development of microemulsion formulations to increase the permeability of acyclovir

The purpose of this study was to improve the permeability of acyclovir (ACV) by developing a water-in-oil microemulsion, since it is an important factor that influences the oral absorption and, consequently, the oral bioavailability of drugs. Pseudoternary phase diagrams (PTPD) were constructed to identify the regions for obtaining microemulsions (ME). From the region of fluid transparent systems, five ME were chosen to evaluate the effect on ACV permeability by using two-compartment horizontal Franz diffusion cells, using a bio-mimetic artificial membrane, which simulates the typical lipophilic characteristics of the biological membranes. The characterization of ME was carried out by PTPD, conductivity determination and Nuclear Magnetic Resonance studies. The formulation that showed the higher incorporation of ACV (81.57 mg/ml) consisted of 13.3% Polysorbate 80, 13.3% ethanol, 6.6% ginger oil and 66% water. An increase in ACV permeability was observed, reaching an apparent permeability coefficient of 1.99.10−6 cm/s, corresponding to a fraction of human absorbed dose of 99.97%, according to the correlation previously established by our research group. These results indicated the ability of ME to improve the permeability of ACV, representing a system with the potential to improve the efficacy of ACV in oral administrated pharmaceutical formulation.

Formulation and Evaluation of Microemulsion of Curcumin in Thymol-Menthol Carrier System

Aim: To formulate and evaluate the Micro emulsion of curcumin in thymol-menthol carrier system.
 Study Design: Curcumin dissolves in mixture of thymol & menthol to reasonable extent.100 mg of curcumin in 1 g of thymol and 0.6 g of menthol mixture was finalized as product mixture. The solution of curcumin in eutectic mixture being oily liquid, it gave the idea for development for the micro emulsion
 Place and Duration of Study: Department of Pharmaceutics and Department of Pharmacognosy, STES’s Smt. Kashibai Navale College of Pharmacy, Kondhwa (BK), National Chemical Laboratory, Pune between June 2016 and May 2017.
 Methodology: Micro emulsion system with eutectic mixture of thymol and menthol was chosen as oil phase and carrier for curcumin, tween 80 as surfactant and ethanol as co-surfactant. Ternary phase diagrams were constructed to obtain the optimum concentration range of oil phase, surfactant and co-surfactant. The micro emulsion of 100 mg curcumin containing 4.95 % oil phase, 33.39 % surfactant, 11.13% co-surfactant, 50:50% of water was optimum. Micro emulsion of curcumin was prepared by water titration method and evaluated for globule size, drug content, pH, viscosity, conductivity and In vitro drug release study. The ex-vivo permeation study for micro emulsion of curcumin was carried out on excised mice skin using Franz Diffusion apparatus. The cytotoxicity study for thymol, menthol was performed on healthy L929 murine fibroblast cell line. Anticancer activity of thymol-menthol eutectic mixture alone and with curcumin was performed on HeLa cell lines.
 Results: The preformulation studies did clearly indicate good compatibility of drug with thymol menthol carrier system. The cytotoxicity study was done on thymol – menthol(TM) as a preformulation aspect to ascertain the toxicity of these two excipients to be tried. It was found that TM was not cytotoxic in 120ug/mL concentration and thus was safe to be used in concentration below 120ug/mL. Batch B1 was optimised. The average globule size of micro emulsion was found to be 131.54 nm, zeta potential was found to be -0.57 mV. The drug content in micro emulsion batch B1 was determined and found to be 74.6%.Permeability study across mice skin ex-vivo model showed 52.38% permeability compared with curcumin alone which was 22.41%. So permeability of curcumin is enhanced substantially with micro emulsion made in thymol and menthol, owing to fact that thymol and menthol act as good permeation enhancers. The In vitro drug release study of micro emulsion was compared with curcumin alone. About 48.75% of curcumin was released from micro emulsion showed increase in release rate.
 Conclusion: Eutectic mixture of thymol and menthol showed promising results as penetration and solubility enhancer for curcumin. Solubility of curcumin was improved so as its rate of permeation which was used to develop formulation of micro emulsion with proven anticancer activity. The solubility of curcumin formulated with combination of eutectic mixture was increased up to 50 %.

Formation of sacha inchi oil microemulsion systems: effects of non-ionic surfactants, short-chain alcohols, straight-chain esters and essential oils.

This study reports the formation of sacha inchi oil (SIO) microemulsions for food and cosmetic applications. Effects of non-ionic surfactants, short-chain alcohols, essential oil and straight-chain esters on the phase behavior and formulation of U-type microemulsion were investigated. Pseudo ternary phase diagrams were constructed to assess the influence of these factors using water titration method. Structural transitions were measured along several water dilution lines using conductivity and viscosity tools. Among four different surfactants, Tween 80 solubilized the maximum oil and induced the formation of a U-type microemulsion system. Oil solubilization was decreased in the presence of short-chain alcohols. In addition, the system containing straight-chain esters as the cosolvent showed a higher expansion effect in the U-type areas than that containing essential oils. Finally, upon water dilution of three systems with SIO/ethyl acetate of 1:1, 1:2 and 1:3, microstructural transition from W/O to bicontinuous occurred at 200 g kg-1 (w/w) water content, and then to O/W structure at 650 g kg-1 (w/w) water content. Straight-chain esters as cosolvent is a potential strategy to extend the dilutability of SIO microemulsions. © 2021 Society of Chemical Industry.

Antioxidant, Antimicrobial and Formulation of Borage (Borago officinalis) Seeds Oil and Leaves Extracts as Microemulsion

Aims: This study aims to investigate antioxidant and antibacterial activities of borage (seeds and leaves) extracts, and to prepare different topical microemulsion formulations using borage oil.
 Study Design: Borage seeds and leaves were collected from Hebron -Palestine, then the borage leaves and seeds were prepared for extraction and then extracted with Soxhlet using ethanol. The antimicrobial and antioxidant activity of the extracts were studied, and then Ternary Phase Diagram was constructed using the borage extracts (from seeds and leaves).
 Methodology: The seeds were cultivated upon their ripening season in April of 2016 from the Halhul mountains in Hebron/Palestine. Soxhlet method was used to extract borage seeds and leaves oil by using ethanol 95%. A ternary phase diagram was constructed by determining appropriate nonionic surfactant to assess the ability for microemulsion formulation and durability of each system. Tween 80 was found to be more suitable to solubilize each of borage seeds and leaves extracts compared with Tween 20 due to its prominent hydrophobic properties. The antibacterial activity was evaluated for both borage seeds and leaves extracts using a well diffusion method against Staphyloococcus aureus, Escherichia coli, &Candida albicans.
 Results: Results showed that the seeds extract has inhibition zone (12 mm) against S. aureus (gram positive bacteria) higher than inhibition zone that leaves extracts exhibited (7.5mm), but no significant effects observed for both extracts against E. coli and C. albicans. In addition, antibacterial activity for microemulsions formulation was measured against S. aureus, E. coli, and C. albicans. Results showed that there is minor activity against S. aureus when compared to PenicillinG and the pure seed oil or leaves extract. In contrast no activity was reported against E. coli and C. albicans. The antioxidant activity was further indicated by the quiet good ability to reduce the FRAP reagent for both extracts with the indication of higher seeds extract activity. This variation is explained by the higher seeds extract content of polyphenol, tocopherol and vitamin C than leaves extract.
 Conclusion: Borage seeds and leaves were extracted, and the extracts were showed antimicrobial and antioxidant activity and showed that they can be used in microemulsion using ternary phase diagram.

Development of bioflavonoid containing chemotherapeutic delivery systems for UV-damaged skin and kangri cancer

Abstract Background The lower abdomen and inner thighs are most likely to become affected by kangri cancer because those areas are exposed to continuous exposure to kangri. Objective In this article, formulation and characterization of a water-in-oil microemulsion of 5-fluorouracil with rutin (R-5FU) for better skin penetration and inhibition of kangri cancer (skin cancer surfactant) is discussed. Method To produce R-5-FU microemulsions, surfactant-cosurfactant was mixed with oil. Distilled water was added dropwise with the help of a burette by gentle stirring at a constant temperature. The surfactant and co-surfactant were mixed into three particular ratios 1:1, 2:1, and 3:1. Further characterizations were performed, such as visual inspection and thermodynamic stability including a stress test and centrifugation. In visual inspection included assessment of the colour, homogeneity, and odour of the formulation of FU microemulsion. Result All three microemulsions, labeled RME1, RME2, and RME3, are highly stable. An oval shape of surface morphology of 5-FU was noticed by using a TEM image. The viscosity of RME3 was found to be 17.25±0.22 pa-s. The average globule size was 100–300 nm for all three RME. The results of human cadaver skin permeability are almost of the same pattern, butRME3 indicates the best skin permeability with negligible side effects on the skin. Conclusion The quantity of 5-FU released from all formulations at 3-hr ranged from 95.57% to 83.67%. None of the three formulations resulted in skin irritation, with irritancy score of zero (IS=0). Observation revealed no lysis, hemorrhage, or coagulation after application.

Enhancement of the Topical Bioavailability and Skin Whitening Effect of Genistein by Using Microemulsions as Drug Delivery Carriers

Genistein, the most abundant isoflavone of the soy-derived phytoestrogen compounds, is a potent antioxidant and inhibitor of tyrosine kinase, which can inhibit UVB-induced skin carcinogenesis in hairless mice and UVB-induced erythema on human skin. In current study, genistein-loaded microemulsions were developed by using the various compositions of oil, surfactants, and co-surfactants and used as a drug delivery carrier to improve the solubility, peremability, skin whitening, and bioavailbility of genistein. The mean droplet size and polydispersity index of all formulations was less than 100 nm and 0.26 and demonstrated the formation of microemulsions. Similarly, various studies, such as permeation, drug skin deposition, pharmacokinetics, skin whitening test, skin irritation, and stability, were also conducted. The permeability of genistein was significantly affected by the composition of microemulsion formulation, particular surfactnat, and cosurfactant. In-vitro permeation study revealed that both permeation rate and deposition amount in skin were significantly increased from 0.27 μg/cm2·h up to 20.00 μg/cm2·h and 4.90 up to 53.52 μg/cm2, respectively. In in-vivo whitening test, the change in luminosity index (ΔL*), tended to decrease after topical application of genistein-loaded microemulsion. The bioavailability was increased 10-fold by topical administration of drug-loaded microemulsion. Conclusively, the prepared microemulsion has been enhanced the bioavailability of genistein and could be used for clinical purposes.

Formulation and In vitro Percutaneous Permeation and Skin accumulation of Voriconazole Microemulsified Hydrogel

The aim of the present study was to prepare and evaluate voriconazole microemulsified hydrogel. The voriconazole microemulsified is prepared by Water Titration Method. In which voriconazole microemulsified incorporated with hydrogel, Blank gels of different polymers were prepared by distilled water. Finally, the carbopol gel was prepared by dispersing 0.5% carbopol w/v and 0.5% aloe vera powder in 100 ml of water with stirring on mechanical stir. Additionally, for preservation of formulations 0.8% methyl paraben was mixed. Oil phase was selected by dissolving the voriconazole pure in different oils, oleic acid, castor oil, coconut oil, olive oil, cooten seed mineral oil and soya oil. Oleic acid was selected on the basis of higher solubility of voriconazole in it. Combination of surfactant and co-surfactant was selected on clear visual observation. Span - 40: propylene glycol in ratio 1:1 and 2:1 selected for further preparation of microemulsion. From the study F-8, F-9, F-10, F-14 and F-15 were selected for further studies. Though F-16, F-17, F-18, F-19 and F-20 formulations are also stable, but rejected due to high concentration of surfactant can cause skin irritation, skin burning and/or other complications. Characterization of selected voriconazole microemulsion formulations were evaluated under various parameters like Droplet size, Zeta potential, Poly Dispersity Index (PDI) and (%) Drug content all results showed.

Design expert assisted formulation, characterization and optimization of microemulsion based solid lipid nanoparticles of repaglinide.

Repaglinide, a member of the meglitinide class of drugs, is a new anti-diabetic agent that is utilized as an oral hypoglycemic agent. Using glyceryl monostearate, cetyl palmitate, and tristearin as lipids and poloxamer 188 as a surfactant, repaglinide-loaded solid lipid nanoparticles were created. Solid lipid nanoparticles were prepared utilizing an o/w microemulsion technique, which included the lipids glyceryl monostearate and tristearin, as well as waxes such as cetyl palmitate and the surfactant poloxamer 188. The mean particle size of the solid lipid nanoparticles formed was around 339nm, with an entrapment efficiency of 82.20%. In-vitro release studies continued to be conducted using the dialysis bag diffusion technique. Within 12h, the cumulative drug release was 88.4%. The results indicate that repaglinide was released more slowly from solid lipid nanoparticles made from tristearin and glyceryl monostearate in an equal ratio. Tristearin found the controlled release and extreme entrapment from other lipid carriers like glyceryl monostearate and cetyl palmitate. Differential scanning calorimetry demonstrates that repaglinide is entangled in amorphous or molecular state within solid lipid nanoparticles. SEM microscopy revealed that the produced repaglinide solid lipid nanoparticles had a spherical shape. After one month of storage at 2-8°C, short-term stability testing revealed no significant alteration.

FORMULASI, KARAKTERISASI DAN UJI STABILITAS MIKROEMULSI MINYAK NILAM (Pogostemon cablin Benth.)

Patchouli oil contains patchouli alcohol as the main component which is a tricyclic tertiary alcohol sesquiterpene compound that is insoluble in water. Microemulsion is a droplet dispersion technology that combines an insoluble liquid with another liquid. The role of surfactants in helping the dispersion process of microemulsion formulation is by reducing the interfacial tension. Microemulsion is a supersolvents carrier, so that both hydrophilic and lipophilic can be administered through a microemulsion system. The purpose of this study was to formulate patchouli oil into a stable microemulsion preparation. This research was conducted by making 4 preparations of patchouli oil microemulsion containing 5% (F1), 10% (F2), and 15% (F3) patchouli oil, and microemulsion without patchouli oil (F0). Evaluation of microemulsion preparations includes organoleptic test, pH measurement, density determination, viscosity test, freeze and thaw test, centrifugation test, and particle size analysis. The test results showed that the microemulsion containing 5% patchouli oil had the most stable characteristics compared to other formulas.

Synthesis and characterization of surface-active ionic liquids for their potential application in enhanced oil recovery

In enhanced oil recovery, most widely used combinations of chemical formulations incorporate surfactants, polymers and alkalis, however, it is important to investigate alternate options which could offer improved performance and superior operational flexibility in comparison to conventional technologies. Surface active ionic liquids (SAILs) are novel functional ionic liquids with amalgamated properties of surfactant and ionic liquid, which represent an interesting alternative especially in harsh reservoir conditions for enhanced oil recovery processes. The present study illustrates a methodological laboratory assessment of synthesised SAILs to investigate their applicability for enhanced oil recovery based on their physicochemical evaluation. FT-IR, 1H NMR and TGA confirmed the chemical structure and thermal stability of the synthesised C12mimBr and C16mimBr. SAILs in aqueous solution were studied to determine their surface and interfacial behaviour under reservoir conditions. The synthesised SAILs showed lower critical micellar concentration ∼ 200 ppm (C16mimBr) and good surface-active properties and high efficiency on the interface adsorption. The interfacial tension was reduced to ultra-low values (range of 10-3 to 10-4) in wide ranges of salinity, concentration, and temperature, thus provide valuable evidence for its application as surfactants in EOR. The phase behaviour studies further suggested the formation of WINSOR-III micro-emulsion, thus making it a robust performance formulation.

Preparation and Evaluation of a Novel Oral Microemulsion Drug Delivery System for Enhancing the Bioavailability of Diltiazem

Diltiazem, a calcium ion cellular influx inhibitor is known for its limited and variable bioavailability. This study is intended to explore the benefits of microemulsion formulation as an oral drug delivery system for immediate release to improve the bioavailability and efficacy of Diltiazem. Methods: Oil in water microemulsion was prepared using the simple water titration method. The optimized formulation was evaluated for physicochemical parameters like viscosity, pH, conductivity, and accelerated stability studies. In vitro release, diltiazem microemulsion was investigated.

Extraction of Crude Oil Endogenous Surfactants by an Optimum Three-Phase Microemulsion System: Relation between Interfacial Behavior and a Molecular Fingerprint Obtained by Ultrahigh-Resolution Mass Spectrometry

A novel method is described to extract crude oil surface active species. It is based on the formation of balanced three-phase microemulsions (optimum Winsor III systems) with a well-defined tempera...

Preformulation studies of thymopentin: analytical method development, physicochemical properties, kinetic degradation investigations and formulation perspective

Thymopentin (TP5) is a synthetic pentapeptide with immunomodulatory properties. Given the previously described poor absorption of TP5, preformulation data is required to support effective formulation development. In this manuscript, an analytical method of TP5 was developed and validated to determine the aqueous solubility, stability, and Log P of TP5. Thermal properties were investigated, and chemical, physical and enzymatic degradation were evaluated. TP5 was informed to load in a microemulsion (ME) system according to the preformulation parameters and characterized for rheological behavior, droplet size, morphology and in vitro drug release. TP5 displayed high aqueous solubility (294.3 mg/mL), low Log P (−4.2) and 2% water content with a melting temperature of 193 °C. TP5 degraded rapidly in alkaline conditions, at elevated temperature, in oxidizing agents, and with UV exposure, however TP5 had a longer half-life in acidic conditions. The fastest enzymatic degradation was with Trypsin (half-life 6.3 h) compared with other digestive enzymes. The different degradation pathways followed first-order kinetics, and half-lives were obtained from the kinetic studies. The TP5 loaded ME exhibited a droplet size of 143 ± 35 nm with a Higuchi-model fitted sustained release profile for 24 h. These data justify and support the design of formulations to stabilize and enhance the absorption of TP5, with a ME formulation demonstrated.