Spray Drying of Asiatic Acid-Palm Oil in Maltodextrin: Improving the Nanoemulsion Characteristics

Combination of Asiatic acid (AA) and palm oil (PO) is promising to be developed. However, both have low solubility, low absorption, rapid metabolism, low bioavailability, and high oxidation which need to be improved in order to provide good activity. Thus, nanoemulsion formulation followed by spray drying were optimized to enhance the physical and chemical characteristics of the products. Lecithin (L), poloxamer188 (P), span80 (S), tween80 (T) were used as surfactants to form nanoemulsion and maltodextrin (M) was used as spray dried matrix component. Different amounts of maltodextrin were optimized at low (M1), medium (M2), and high (M3) levels. Characterization and evaluation were carried out on products, including particle size, morphology, product recovery (yield), drug content, solubility, and dissolution rate. The characterization results showed that nanoemulsion was successfully prepared and spray dried microparticles with a good physical form were obtained. The microparticles could be rapidly redispersed to form size of 149.0 – 271.1 nm with the zeta potential value lower than -30mV. Both physical and chemical stability of the microparticles showed no significant difference after 6-month storage. Lecithin-Tween-medium Maltodextrin (LTM2) formula showed the most optimum results with good physical characteristics and a high dissolution rate. In vitro release profile of LTM2 showed area under the curve (AUC) and dissolution efficiency at 180min values of 14725.10 +- 480.60 and 81.81 +- 2.67%, respectively. It could be concluded that spray dried microparticles of AA-PO nanoemulsion formulation improved the physical and chemical characteristics of both compounds presumably suitable good bioavailability and activity

Antihypertensive activity of spray-dried nanoemulsion containing Asiatic acid-Palm oil in high salt diet-fed rats

Asiatic acid (AA) is a compound isolated from Centella asiatica, which possesses significant antihypertensive activity. Several studies have shown that its hypertensive activity can be attributed to various mechanisms, such as Angiotensin-Converting-Enzyme (ACE) inhibition in the renin-angiotensin-aldosterone system (RAAS) pathway. Meanwhile, palm oil (PO) is an antioxidant, which has proven to have synergistic effects with the compound by preventing arterial thrombosis and atherosclerosis. Despite these synergistic effects, AA dosage in antihypertensive therapy has been reported to be relatively high compared to the common synthetic drug captopril. Therefore, this study aimed to produce spray-dried powder of nanoemulsion to enhance the solubility of AA, decrease the possibility of oxidation, and increase its activity. Redispersed AA nanoparticles were also successfully obtained during the synthesis process. Several evaluations were carried out, including particle size, particle distribution, zeta potential, cell viability, and antihypertensive activity in rats to ensure the improvement of physicochemical characteristics and activity as antihypertensive agent. The results showed that AA succeeded in forming nanoemulsion with excipients. In addition, it was encapsulated in a maltodextrin carrier, exhibiting good physicochemical characteristics and safety to the Caco-2 cells. The redispersion of the spray-dried powder yielded nanoparticles with a size of 217.4 ± 10.196 nm. The spray-dried nanoemulsion of AA also had faster effect than non-formulated AA (raw powder) in lowering the blood pressure of hypertensive Sprague-Dawley (SD) rats

Antihypertensive activity of spray-dried nanoemulsion containing Asiatic acid-Palm oil in high salt diet-fed rats

Asiatic acid (AA) is a compound isolated from Centella asiatica, which possesses significant antihypertensive activity. Several studies have shown that its hypertensive activity can be attributed to various mechanisms, such as Angiotensin-Converting-Enzyme (ACE) inhibition in the renin-angiotensin-aldosterone system (RAAS) pathway. Meanwhile, palm oil (PO) is an antioxidant, which has proven to have synergistic effects with the compound by preventing arterial thrombosis and atherosclerosis. Despite these synergistic effects, AA dosage in antihypertensive therapy has been reported to be relatively high compared to the common synthetic drug captopril. Therefore, this study aimed to produce spray-dried powder of nanoemulsion to enhance the solubility of AA, decrease the possibility of oxidation, and increase its activity. Redispersed AA nanoparticles were also successfully obtained during the synthesis process. Several evaluations were carried out, including particle size, particle distribution, zeta potential, cell viability, and antihypertensive activity in rats to ensure the improvement of physicochemical characteristics and activity as antihypertensive agent. The results showed that AA succeeded in forming nanoemulsion with excipients. In addition, it was encapsulated in a maltodextrin carrier, exhibiting good physicochemical characteristics and safety to the Caco-2 cells. The redispersion of the spray-dried powder yielded nanoparticles with a size of 217.4 ± 10.196 nm. The spray-dried nanoemulsion of AA also had faster effect than non-formulated AA (raw powder) in lowering the blood pressure of hypertensive Sprague-Dawley (SD) rats. Graphical abstract