Development and optimization of Benjakul microemulsion formulations for enhancing topical anti-inflammatory effect and delivery

Pranporn Kuropakornpong , Arunporn Itharat , Buncha Ooraikul, Raimar Loebenberg, Neal M. Davies


Background and purpose: Benjakul (BJK) is a combination of five botanical herbal constituents widely used in Thai traditional medicine as an anti-inflammatory remedy. This study aimed to develop a novel topical microemulsion containing BJK for clinical use.

Experimental approach: The microemulsions were produced by a phase inversion temperature (PIT) methodology. Physicochemical properties and stability were evaluated to determine an optimal formula. The stable BJK-loaded microemulsion formulas were then subjected to in vitro studies for their anti-inflammatory activity, skin cell toxicity, drug permeation, and stability.

Finding/Results: Two novel formulations containing isopropyl myristate (ME1-BJK and ME2-BJK) passed the compendial stability test. BJK constituents were completely dissolved in the oil phase and incorporated into the microemulsion base Transcutol® and Labrasol® avoiding the use of alcohol, both microemulsion formulations demonstrated high anti-inflammatory activity with IC50 values of 3.41 ± 0.36 and                                      3.95 ± 1.73 µg/mL, respectively. However, dissolution of ME1-BJK showed a superior release profile through both lipophilic and hydrophilic membranes with the highest accumulated amount at 4 h of 25.13% and                          38.06%, respectively. All tested formulations of BJK extract demonstrated no apparent skin cell toxicity at concentrations up to 50 µg/mL. After six-month storage under accelerated conditions, there were no significant changes in anti-inflammatory activity.

Conclusions and implications: A novel and stable BJK-loaded microemulsion formulation was successfully developed with excellent release and stability properties. Further clinical research to evaluate pain reduction, edema, and skin irritation using this formulation in animal models is ongoing.


Keywords: Anti-inflammatory activity; Benjakul; Microemulsion; Phase inversion temperature.

Full Text:



WCG FDA news. FDA releases black-box template for NSAIDs. 2005. Available from:

Stanos SP, Galluzzi KE. Topical therapies in the management of chronic pain. Postgrad Med. 2013;125(4 Supp1):25-33.

DOI: 10.1080/00325481.2013. 1110567111.

Feingold KR. Lamellar bodies: the key to cutaneous barrier function. J Invest Dermatol. 2012;132(8):1951-1953.

DOI: 10.1038/jid.2012.177.

Kohli AK, Alpar HO. Potential use of nanoparticles for transcutaneous vaccine delivery: effect of particle size and charge. Int J Pharm. 2004;275(1-2):13-17.

DOI: 10.1016/ j.ijpharm.2003.10.038.

Shakeel F, Baboota S, Ahuja A, Ali J, Shafiq S. Skin permeation mechanism and bioavailability enhancement of celecoxib from transdermally applied nanoemulsion. J Nanobiotechnology. 2008;6:8.

DOI: 10.1186/1477-3155-6-8.

Gupta A, Eral HB, Hatton TA, Doyle PS. Nanoemulsions: formation, properties and applications. Soft Matter. 2016;12(11):2826-2841.

DOI: 10.1039/ C5SM02958A.

Jasmina H, Džana O, Alisa E, Edina V, Ognjenka R. Preparation of Nanoemulsions by High-Energy and Low Energy Emulsification Methods. In: CMBEBIH. Singapore: Springer; 2017. pp. 317-322.

DOI: 10.1007/978-981-10-4166-2_48.

Itharat A, Sakpakdeejaroen I. Determination of cytotoxic compounds of Thai traditional medicine called Benjakul using HPLC. J Med Assoc Thai. 2010;93 Suppl 7:S198-S203.

PMID: 21294415.

Ruangnoo S, Itharat A, Sakpakdeejaroen I, Rattarom R, Tappayutpijam P, Pawa KK. In vitro cytotoxic activity of Benjakul herbal preparation and its active compounds against human lung, cervical and liver cancer cells. J Med Assoc Thai. 2012;95 Suppl 1:S127-S134.

PMID: 23964455.

Makchuchit S, Rattarom R, Itharat A. The anti-allergic and anti-inflammatory effects of Benjakul extract (a Thai traditional medicine), its constituent plants and its some pure constituents using in vitro experiments. Biomed Pharmacother. 2017;89:1018-1026.

DOI: 10.1016/j.biopha.2017.02.066.

Burodom A, Itharat A. Inflammatory suppressive effect of Benjakul, a Thai traditional medicine on intestinal epithelial cell line. J Med Plant Res. 2013;7(44):3286-3291.

DOI: 10.5897/JMPR2013.5206.

Thummawan C, Itharat A, Asasutjarit R. Anti-inflammatory activities of nanoemulsion containing Benjakul Remedy extract. Thammasat Med J. 2019;19(2):359-370.

Kuropakornpong P, Itharat A, Panthong S, Sireeratawong S, Ooraikul B. In vitro and in vivo anti-inflammatory activities of Benjakul: a potential medicinal product from Thai traditional medicine. Evid Based Complement Alternat Med. 2020;2020:9760948,1-8.

DOI: 10.1155/2020/9760948.

Rachawat P, Pinsornsak P, Kanokkangsadal P, Itharat A. Clinical efficacy and safety of Benjakul remedy extract for treating primary osteoarthritis of knee compared with diclofenac: double blind, randomized controlled trial. Evid Based Complement Alternat Med. 2017;2017:9593580,1-9.

DOI: 10.1155/2017/9593580.

Jintapattanakit A. Preparation of nanoemulsions by phase inversion temperature (PIT). Pharm Sci Asia. 2018;45(1):1-12

DOI: 10.29090 /PSA.2018.01.001.

Tewtrakul S, Subhadhirasakul S. Effects of compounds from Kaempferia parviflora on nitric oxide, prostaglandin E2 and tumor necrosis factor-alpha productions in RAW264. 7 macrophage cells. J Ethnopharmacol. 2008;120(1):81-84.

DOI: 10.1016/j.jep.2008.07.033.

Kakatum N, Pinsornsak P, Kanokkangsadal P, Ooraikul B, Itharat A. Efficacy and safety of sahastara remedy extract capsule in primary knee osteoarthritis: a randomized double-blinded active-controlled trial. Evid Based Complement Alternat Med. 2021;2021:6635148,1-10.

DOI: 10.1155/2021/6635148.

Jantarat C, Sirathanarun P, Boonmee S, Meechoosin W, Wangpittaya H. Effect of piperine on skin permeation of curcumin from a bacterially derived cellulose-composite double-layer membrane for transdermal curcumin delivery. Sci Pharm. 2018;86(3):39-52.

DOI: 10.3390/scipharm86030039.

Haghighi M, Khalvat A, Toliat T, Jallaei SH. Comparing the effects of ginger (Zingiber officinale) extract and ibuprofen on patients with osteoarthritis. Arch Iranian Med. 2005;8(4):267-271.

Pooprommin P, Pinsornsak P, Itharat A. Evaluation of physical stability and preliminary study on effectiveness of Benjakul cream in the treatment of primary knee osteoarthritis patients. Thammasat Med J. 2019;19(4):637-644.

Rattarom R, Sakpakdeejaroen I, Itharat A. Cytotoxic effects of the ethanolic extract from Benjakul formula and its compounds on human lung cancer cells. Thai J Pharmacol. 2010;32(1):99-101.

Panthong S, Imai Y, Matsuoka T, Suzuki W, Watanabe T, Terada Y, et al. The role of Piper chaba Hunt. and its pure compound, piperine, on TRPV1 activation and adjuvant effect. BMC Complement Altern Med. 2020;20(1):134-142.

DOI: 10.1186/ s12906-020-02917-4.

Yang T, Sheng HH, Feng NP, Wei H, Wang ZT, Wang CH. Preparation of andrographolide-loaded solid lipid nanoparticles and their in vitro and in vivo evaluations: characteristics, release, absorption, transports, pharmacokinetics, and antihyperlipidemic activity. J Pharm Sci. 2013;102(12):4414-4425.

DOI: 10.1002/jps.23758.


  • There are currently no refbacks.

Creative Commons LicenseThis work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License which allows users to read, copy, distribute and make derivative works for non-commercial purposes from the material, as long as the author of the original work is cited properly.