DEVELOPMENT OF FORSKOLIN MICROEMULSION GEL FOR LIPOLYSIS AGENT BY

• Main Author: Nafi'ah, Rahma
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71087
• Institution: Institut Teknologi Bandung

In uneven skin layers, lipid accumulation can occur in the hypodermis layer and adipose tissue. Lipolysis is a method to reduce lipid levels through the process of breaking down lipids through the hydrolysis of triglycerides into fatty acids and glycerol. One of the substances for lipolysis is forskolin. Forskolin is a secondary metabolite obtained from the root of Coleus forskohlii. Forskolin can activate adenylate cyclase in adipose cells to form cyclic adenosine monophosphate. Increased levels of cyclic adenosine monophosphate can increase lipolysis reactions in lipid tissue. Forskolin has several pharmacological effects, including for the treatment of heart failure, dilation of the respiratory tract and alleviating eye pressure in glaucoma patients when used orally. This study aims to develop a topical microemulsion formula that can deliver forskolin to adipose tissue. Microemulsion is a colloidal dispersion composed of oil, surfactant, cosurfactant and water. Microemulsions can be used to increase solubility, stability, and penetration enhancher of active pharmaceutical ingredients used topically. Forskolin has low solubility and can be hydrolyzed in water, so the use of a microemulsion system is expected to improve its solubility, stability, and penetration in topical use. The stages of this research included: forskolin confirmation test, forskolin solubility test in oil, surfactant and cosurfactant, verification of analytical method, microemulsion formulation, characterization of forskolin microemulsion, stability test of forskolin microemulsion formula, selection of gel base, in vitro diffusion test, in vivo lipolysis test, tissue examination skin and irritation test. The forskolin confirmation test includes examining the Fourrier transform infrared spectrum and chromatogram with high performance liquid chromatography between the sample forskolin and the reference standard forskolin. The characterization test results showed that there was a match between the Fourrier transform infrared spectrum and the sample forskolin chromatogram and standard forskolin that appeared at retention time of 6,75 minutes and match factor of 90.49%. The Solubility test showed that forskolin was soluble in Maisine CC (5,23±0,22 mg/mL), MCT (3,24±0,06 mg/mL), Tween 20 (20,88±0,73 mg/mL), PEG 400 (23,08±0,10 mg/mL) and propylene glycol (4,67±0,10 mg/mL). Microemulsion was made by phase titration method. Formula optimization was carried out by selecting the levels of surfactants, cosurfactants, oils and forskolin in the microemulsion. The optimal microemulsion formula is a formula composed of Maisine CC, Tween 20, and PEG 400 with a ratio of 4:25:5% or the FA5.2. This formula can increase the solubility of forskolin by 2,19 ± 0,05 mg/mL Formula FA5.2 was tested for stability including globule size, polydispersion index, forskolin content and pH of the formula for 90 days at 25°C ± 2°C/60% ± 5% relative humidity and 40°C ± 2°C/75% ± 5% relative humidity. Stability test results showed that the formula was stable at 25°C ± 2°C/60% ± 5% relative humidity with a globule size of 27.00 ± 2.46 nm, polydispersion index of 0.30 ± 0.10, forskolin content of 97, 78 ± 5.69 % against initial levels and pH 6,35 ± 0,19. Examination of the optimal formula globule size was determined by transmission electron microscopy showing the size of the microemulsion globules having a size of arround 30 nm. The results of spectral examination with Fourrier transform infrared showed that no new spectra were formed in the formula compared to the microemulsion ingredients, this indicated that no new functional groups were formed in FA5.2. The selection of the gelling agent was carried out by incorporating the microemulsion into the gel base. The gel base used was HPMC with high viscosity type which could form FA5.2.G1 microemulsion gel with a globule size of 21.03 ± 0.77 nm, a polydisperse index of 0,31 ± 0,03 and a viscosity of 4485 ± 143,37 cPs. Diffusion test in vitro of forskolin using Franz diffusion cell with Spangler synthetic membrane. This test compares the percentage of forskolin that diffuses in FA5.2 to the percentage of forskolin that diffuses in FA5.2.G1 and the percentage of forskolin that diffuses in other delivery systems, namely micellar and emulgel. The results showed that forskolin in FA5.2 could diffuse around 36,81 ± 2,08 %, while in FA5.2.G1 it was 18,50 ± 0,32 % and micellar was 19,58 ± 0,47 % while forskolin in emulgel did not diffuse during 6 hours of observation. The lipolytic activity of the optimal formula was tested in vivo in male Swiss Webster mice fed a high-fat diet. This test was approved by the Ethics Commission for the Use of Experimental Animals, Bandung Institute of Technology No. 3/KEPHP-ITB/10-2021. This test was approved by the Ethical Committee on Animal Use. The test results showed FA5.2.G1 once application could provide weight change in body weight by 1,91 ± 6,15% (p = 0,01), decreased abdominal circumference by -2,37 ± 3,25%, and released glycerol by 16,68±0,98 nmol/hour (p= 0,03) against the control. FA5.2.G1 two applications can reduce body weight by -3,81 ± 3,17 % (p = 0,001), abdominal circumference by -5,83 ± 4,54 % (p = 0,03) against control and glycerol release was 15,99 ± 1,55 nmol/hour (p= 0,017) against the control. The results of skin tissue examination indicated changes in lipid integrity in the adipose tissue of the hypodermis layer. This change occurred in the FA5.2.G1, FA5.2.G1-2, FA5.2G1 base and reference gel groups. While the group given emulgel preparations, the control group and the normal group did not change lipid integrity. In vivo dermal irritation test on rabbit skin has been approved by the Ethical Commission for the Use of Experimental Animals with letter No. 02/KEPHP-ITB/10-2021. The irritation results showed primary irritation index FA5.2 = 0,11 and FA5.2.G1 = 0 which were categorized as very mild irritation or could be ignored. Based on the research results it can be concluded that forskolin can be formulated in microemulsion preparations, where the solubility of forskolin in the FA5.2 microemulsion formula is 2,19 ± 0,05 mg/mL. Stability test showed that the formula had globule size, polydispersion index, grade and pH which were stable at storage temperature of 25°C ± 2°C and 60% ± 5% relative humidity for 90 days. In the lipolysis test, the FA5.2G1 formula can give lipolysis reactions with decreased body weight (-3,81 ± 3,17 %), decreased abdominal circumference (-5,83 ± 4,54 %) and low levels of glycerol release ( 15,99 ± 1,54 nmol/hour) in animals fed high fat diet. In the FA5.2G1 irritation test, it did not give an irritation response to the skin with an IIP = 0.