OPTIMASI CARBOPOL 940 DAN HPMC PADA FORMULASI FORMULASI FACIAL WASH GEL TEA TREE OIL MENGGUNAKAN METODE SIMPLEX LATTICE DESIGN

ABSTRAK
Latar Belakang: Jerawat (acne vulgaris) akibat bakteri Propionibacterium acnes, Staphylococcus aureus, dan S. epidermidis dapat diatasi dengan Tea Tree Oil (TTO) sebagai antimikroba alami yang aman dari risiko resistensi. Penelitian ini bertujuan mengoptimasi kombinasi gelling agent Carbopol 940 dan HPMC untuk menghasilkan sediaan facial wash gel TTO yang stabil dan berkualitas.
Metode: Penelitian eksperimental ini menggunakan metode Simplex Lattice Design (SLD) pada Design Expert 13.0. Evaluasi stabilitas fisik dilakukan sebelum dan sesudah cycling test sebanyak 6 siklus (suhu 4°C dan 40°C, masing-masing 24 jam). Parameter pengujian meliputi organoleptik, homogenitas, pH, viskositas, daya sebar, tinggi busa, serta sinkronisasi syneresis/swelling. Hasil prediksi diverifikasi menggunakan uji One Sample T-Test pada SPSS.
Hasil: Formula optimum diperoleh pada kombinasi Carbopol 940 (1,5%) dan HPMC (0,5%) dengan nilai desirability sempurna (1,000). Sediaan terbukti stabil secara fisik sebelum dan sesudah cycling test (berwarna putih susu, berbau khas TTO, homogen, serta bebas syneresis/swelling). Hasil evaluasi aktual menunjukkan nilai rata-rata pH 7,83, viskositas 8.558 mPa.S, daya sebar 5 cm, dan tinggi busa 1,4 cm.
Kesimpulan: Metode SLD berhasil menentukan kombinasi ideal Carbopol 940 (1,5%) dan HPMC (0,5%) sebagai basis facial wash gel TTO. Formula ini terbukti memiliki mutu fisik yang baik, stabil dalam penyimpanan dipercepat, dan memenuhi standar sediaan pembersih wajah topikal.
Kata kunci: Carbopol 940, Facial wash gel, HPMC, Simplex lattice design, Tea tree oil.

ABSTRACT
Background: Acne vulgaris, triggered by pathogenic bacteria such as Propionibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis, can be effectively treated with Tea Tree Oil (TTO) as a broad-spectrum natural antimicrobial without the risk of bacterial resistance. This study aims to optimize the combination of Carbopol 940 and HPMC as gelling agents to develop a stable and high-quality TTO facial wash gel.
Methods: This experimental study utilized the Simplex Lattice Design (SLD) method via Design Expert 13.0. Physical stability was evaluated before and after a 6-cycle accelerated stability test (cycling test at 4°C and 40°C for 24 hours each). Evaluated parameters included organoleptic properties, homogeneity, pH, viscosity, spreadability, foam height, and syneresis/swelling phenomena. Predictive models were statistically verified using a One-Sample T-Test in SPSS.
Results: The optimum formula was achieved with a combination of Carbopol 940 (1.5%) and HPMC (0.5%), yielding a perfect desirability score of 1.000. The optimal gel remained physically stable before and after the cycling test (milky white appearance, characteristic TTO odor, homogeneous, and free from syneresis or swelling). Actual physical characteristics showed a mean pH of 7.83, viscosity of 8,558 mPa.s, spreadability of 5 cm, and foam height of 1.4 cm.
Conclusion: The SLD method successfully identified the ideal combination of Carbopol 940 (1.5%) and HPMC (0.5%) for a Tea Tree Oil facial wash gel base. The optimized formulation demonstrated good physical quality, consistent accelerated stability, and compliance with topical skin cleanser standards.
Keywords: Carbopol 940, Facial wash gel, HPMC, Simplex lattice design, Tea tree oil.