https://bestjournal.untad.ac.id/index.php/kovalen <p><strong>KOVALEN: Jurnal Riset Kimia</strong> is a peer-reviewed journal of chemistry that published by the Chemistry Department, Tadulako University, Indonesia. This journal is concerned with publishing original research articles, review articles, and current issues related to chemistry. Publishing frequency 3 issues per year, in April, August, and December. KOVALEN has been established since 2015 with volume 1 no 1 (December 2015) and has been <strong>accredited by DIKTI in the SINTA 4 category (No. 164/ E/ KPT/2021)</strong>.</p> <p><strong>ISSN:&nbsp;<strong><strong>2477-5398 (electronic)</strong></strong></strong></p> <p>The Scope of this journal includes:<br>1. Theoretical and environmental chemistry study<br>2. Material and biomaterial synthesis, including their application&nbsp;<br>3. Isolation, purification, and modification of the natural product<br>4. Development and validation of analytical methods<br>5. Isolation and application of enzyme</p> Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University en-US KOVALEN: Jurnal Riset Kimia 2477-5398 https://bestjournal.untad.ac.id/index.php/kovalen/article/view/17827 <p>Methanol extract of soursop leaves contains various bioactive compounds such as alkaloids, saponins, tannins, and flavonoids. To increase the absorption of these compounds, a nanoemulsion formulation of soursop leaf extract was carried out. Extraction was carried out using the maceration method using 96% methanol, followed by a thickening process using a rotary evaporator and freeze drying to obtain the dry extract. The nanoemulsion preparation was made from methanol extract of soursop leaves (<em>Annona muricata L.</em>) using Virgin Coconut Oil (VCO) as the oil phase and Tween 80 as a surfactant. The nanoemulsion was formulated using a high-energy method using an ultrasonicator. Two formulas were tested (F1 and F2) and evaluated through organoleptic tests, clarity (transmittance), physical stability (centrifugation), solubility, emulsion type, storage test (freeze-thaw), and measurement of droplet size and polydispersity index with a Particle Size Analyzer (PSA). The results showed that formula F1 had the most optimal characteristics, with a clarity of 80% indicating better droplet dispersion with an average droplet size of 13.96 nm and a polydispersity index of 0.216 indicating the successful formation of a stable and uniform nanoemulsion. Nanoemulsions showed good physical stability, were soluble in polar and semi-polar solvents, and were oil-in-water (O/W) type supporting increased solubility and availability of active compounds in air-based systems. These results indicate that F1 is the most potential formula to increase the bioavailability of active compounds in soursop leaves and can be further developed as a carrier system candidate in pharmaceutical preparations.</p> Ratih Dyah Puspitasari Desfira Sarani Dina Erliana Munifilia Ekasari Copyright (c) 2025 KOVALEN: Jurnal Riset Kimia 2025-12-29 2025-12-29 11 2 54 62 10.22487/kovalen.2025.v11.i2.17827 https://bestjournal.untad.ac.id/index.php/kovalen/article/view/17909 <p>Methanol extract of soursop leaves contains various bioactive compounds such as alkaloids, saponins, tannins, and flavonoids. To increase the absorption of these compounds, a nanoemulsion formulation of soursop leaf extract was carried out. Extraction was carried out using the maceration method using 96% methanol, followed by a thickening process using a rotary evaporator and freeze drying to obtain the dry extract. The nanoemulsion preparation was made from methanol extract of soursop leaves (<em>Annona muricata L.</em>) using Virgin Coconut Oil (VCO) as the oil phase and Tween 80 as a surfactant. The nanoemulsion was formulated using a high-energy method using an ultrasonicator. Two formulas were tested (F1 and F2) and evaluated through organoleptic tests, clarity (transmittance), physical stability (centrifugation), solubility, emulsion type, storage test (freeze-thaw), and measurement of droplet size and polydispersity index with a Particle Size Analyzer (PSA). The results showed that formula F1 had the most optimal characteristics, with a clarity of 80% indicating better droplet dispersion with an average droplet size of 13.96 nm and a polydispersity index of 0.216 indicating the successful formation of a stable and uniform nanoemulsion. Nanoemulsions showed good physical stability, were soluble in polar and semi-polar solvents, and were oil-in-water (O/W) type supporting increased solubility and availability of active compounds in air-based systems. These results indicate that F1 is the most potential formula to increase the bioavailability of active compounds in soursop leaves and can be further developed as a carrier system candidate in pharmaceutical preparations.</p> Imas Masriah Devi Lestari Sulwiyatul Kamariyah Sani Inten Pangestika Dikki Miswanda Copyright (c) 2025 KOVALEN: Jurnal Riset Kimia 2025-12-29 2025-12-29 11 2 63 72 10.22487/kovalen.2025.v11.i2.17909 https://bestjournal.untad.ac.id/index.php/kovalen/article/view/17922 Eva Musifa Neza Rahayu Palapa Titah Maharti Nugraheni Miftahun Naimah Copyright (c) 2025 KOVALEN: Jurnal Riset Kimia 2025-12-29 2025-12-29 11 2 73 80 10.22487/kovalen.2025.v11.i2.17922