Pengaruh tipe emulsi sederhana dan emulsi ganda terhadap pola pelepasan Natrium Salisilat secara In Vitro

AINUROFIQ, Ahmad, Dr. Marchaban, DESS.,Apt

2006 | Tesis | S2 Ilmu Farmasi

Emulsi dapat digolongkan menjadi dua jenis, yaitu emulsi sederhana yang terdiri dari tipe a/m dan tipe m/a, serta emulsi ganda yang terdiri dari tipe a/m/a dan tipe m/a/m. Tipe emulsi yang berbeda diperkirakan akan berpengaruh terhadap pola pelepasan obatnya. Adapun tipe emulsi yang dihasilkan dipengaruhi oleh faktor formulasi. Penelitian ini bertujuan untuk mengetahui pengaruh berbagai tipe emulsi terhadap pola pelepasan obatnya. Percobaan pendahuluan dilakukan untuk mendapatkan formula terbaik untuk setiap tipe emulsi, berdasarkan pemilihan alat, emulgator, perbandingan fase dalam dengan fase luar serta pemilihan konsentrasi natrium salisilat yang tepat. Formula dipilih yang paling stabil. Hasil terpilih dari empat tipe emulsi tersebut dievaluasi secara umum (homogenitas, warna, konsistensi, bau, redispersibilitas dan kecepatan tuang) dan dievaluasi sifat fisik (rasio pemisahan, viskositas, tipe emulsi, visualisasi mikroskopik). Selanjutnya diuji pola pelepasan obat dari setiap tipe emulsi secara in vitro. Hasil penelitian terbaik menggunakan alat ultra-turrax pada emulsi tipe a/m dan m/a. Sedangkan emulsi a/m/a dan m/a/m menggunakan alat ultra-turrax pada tahap pertama dan alat stirer pada tahap kedua. Emulgator span 80 digunakan pada emulsi a/m dengan konsentrasi 10% dari berat total emulsi, emulgator xanthan gum untuk emulsi tipe m/a dengan konsentrasi 1% dari berat total emulsi, emulsi tipe a/m/a dan m/a/m menggunakan emulgator terbaik dari emulsi sederhana tersebut. Natrium salisilat yang digunakan 1% dari berat total emulsi. Evaluasi rasio pemisahan dengan stress condition pada temperatur 50°C selama 10 hari menunjukkan formula terbaik dari emulsi tipe m/a dan tipe a/m/a belum mengalami pemisahan, sedangkan emulsi tipe a/m dan m/a/m sudah mengalami pemisahan pada hari pertama. Pengujian pelepasan natrium salisilat dari semua tipe emulsi menunjukkan kinetika pelepasan orde satu dengan mekanisme pelepasan pada tipe a/m dominan secara erosi, tipe m/a secara difusi, sedangkan tipe a/m/a dan tipe m/a/m menunjukkan mekanisme keduanya (erosi dan difusi). Adapun konstanta kecepatan pelepasan pada emulsi tipe m/a, a/m, m/a/m, dan a/m/a masing-masing -0,1769 jam-1, -0,0034 jam-1, -0,0051 jam-1, dan -0,0059 jam-1

The emulsion can be classified into two types: simple emulsion consisting of w/o and o/w types, and multiple emulsion consisting of w/o/w and o/w/o types. Different type of could result to different effect in its drug release profile. This study was aimed to identify the effect of various emulsion types to their drug release profile. A preliminary experiment was conducted to obtain the most suitable formula for each type of emulsion, based on tool selection, emulgator, the ratio of internal to external phases as well as the selection of sodium salicylate concentration. The most stable formula was used in the next experiments. The formulas resulted from these four types of emulsion were then evaluated in general (homogeneity, color, consistence, smell, redispersibility, and rate of pouring) and their physical properties (rate of separation, viscosity, type of emulsion, microscopic visualization). Subsequently, drug release profile from each type of emulsion was determined in vitro. The best formula by ultra-turrax at 9500 rpm for w/o and o/w emulsion. Whereas w/o/w and o/w/o emulsion by ultra-turrax 8000 rpm at first phase and stirrer 500 rpm at second phase. Formulation with 10% span 80 of emulsion weight was used as emulgator for w/o emulsion, whereas 1% xanthan gum of emulsion weight was used for o/w emulsion. Emulsions of w/o/w and o/w/o types used the best emulgator of the simple emulsions. The internal phase was drug solution containing 1% sodium salicylate of emulsion weight was used in the experiment and no salt in the outer continuous phase. The evaluation of separation rate under stress condition at a temperature of 50 oC during a ten days showed that the best formula of o/w and w/o/w emulsions has not yet separated, whereas formula of w/o and o/w/o emulsions has already separated on the first day. Sodium salicylate release from all types of emulsion were in the first order kinetic with an erosion mechanism was dominant in w/o type, a diffusion mechanism was dominant in o/w type, whereas w/o/w and o/w/o types showed both erosion and diffusion mechanism. The release rate constant for emulsion of o/w type, w/o type, o/w/o type, w/o/w type were -0,1769 hour-1, -0,0034 hour-1, -0,0051 hour-1, and -0,0059 hour-1 respectively.

Kata Kunci : Emulsi,Pola Pelepasan Obat,Natrium Salisilat, general evaluation, physical properties evaluation, drug release profile, sodium salicylate, simple emulsion, multiple emulsion