Uji In Vitro dan Ex Vivo Formulasi Sediaan Nanoemulsi Ekstrak Kumis Kucing dan Daun Alpukat sebagai Anti Urolitiasis

Abstract

Urolitiasis merupakan penyakit yang ditandai dengan terbentuknya batu saluran kemih akibat endapan kristal, terutama kalsium oksalat. Pemanfaatan tanaman obat seperti daun alpukat (Persea americana Mill.) dan kumis kucing (Orthosiphon aristatus (Blume) Miq.) berpotensi menjadi alternatif terapi karena memiliki aktivitas antioksidan, diuretik, dan antilitiasis. Senyawa bioaktif yang terkandung memiliki kelarutan dan bioavailabilitas yang rendah. Penelitian ini bertujuan mengembangkan nanoemulsi kombinasi ekstrak daun alpukat dan kumis kucing serta mengevaluasi karakteristik fisikokimia, pelepasan zat aktif secara in vitro, dan aktivitas antiurolitiasis secara ex vivo. Formulasi diawali dengan uji kelarutan, penyusunan diagram fase pseudo-ternary, dan karakterisasi nanoemulsi meliputi ukuran partikel, indeks polidispersitas (PDI), dan potensial zeta. Uji in vitro drug release dilakukan menggunakan metode dialysis bag, sedangkan ex vivo dengan pengukuran ion kalsium menggunakan Atomic Absorption Spectrophotometry (AAS). Hasil penelitian menunjukkan bahwa Tween 80, Span 80, propilen glikol, dan isopropil miristat merupakan komponen optimum dalam formulasi nanoemulsi. Rasio Smix 1:1 menghasilkan daerah nanoemulsi paling luas dan stabil. Formulasi terbaik memiliki ukuran partikel 51.15–165.2 nm. Formulasi F8 (rasio ekstrak 4:1; Smix:Oil 8:2) menunjukkan pelepasan zat aktif tertinggi sebesar 77.87% pada jam ke-6. Uji ex vivo menunjukkan nanoemulsi mampu meningkatkan aktivitas peluruhan batu kalsium oksalat dibandingkan kontrol. Nanoemulsi kombinasi ekstrak daun alpukat dan kumis kucing berpotensi dikembangkan sebagai kandidat fitofarmaka untuk pencegahan dan terapi urolitiasis.

Urolithiasis is a urinary tract disorder characterized by the formation of urinary stones due to crystal deposition, predominantly calcium oxalate. Medicinal plants such as avocado leaves (Persea americana Mill.) and cat’s whiskers (Orthosiphon aristatus (Blume) Miq.) have potential as alternative therapies because of their antioxidant, diuretic, and antiurolithiasis properties. However, their bioactive compounds exhibit poor solubility and low bioavailability. This study aimed to develop a nanoemulsion containing a combination of avocado leaf and cat’s whiskers extracts and to evaluate its physicochemical characteristics, in vitro drug release profile, and ex vivo antiurolithiasis activity. The formulation process included solubility studies, pseudo-ternary phase diagram construction, and nanoemulsion characterization, including particle size, polydispersity index (PDI), and zeta potential measurements. The in vitro drug release study was performed using the dialysis bag technique, while the ex vivo evaluation was conducted by measuring calcium ion levels using Atomic Absorption Spectrophotometry (AAS). The results showed that Tween 80, Span 80, propylene glycol, and isopropyl myristate were the optimum components for nanoemulsion formulation. A Smix ratio of 1:1 produced the largest and most stable nanoemulsion region. The optimized formulations exhibited particle sizes ranging from 51,15 to 165,2 nm. Formulation F8 (extract ratio 4:1; Smix:Oil ratio 8:2) demonstrated the highest drug release, reaching 77,87% at the 6th hour. The ex vivo study indicated that the nanoemulsion enhanced calcium oxalate stone dissolution compared with the control group.m These findings suggest that the nanoemulsion containing combined avocado leaf and cat’s whiskers extracts has promising potential as a phytopharmaceutical candidate for the prevention and treatment of urolithiasis.