Pharmaceutical and Biomedical Sciences Journal Volume 7.
, 2025, 43-53
________________________________________________________
The Effect of Gelatin and Propylene Glycol on the Penetration Rate of Asiaticoside from Centella asiatica (L.
) Urb Leaf Extract Gel Sabrina Dahlizar1.
Yuni Anggraeni 1.
Atina Munfarikhatin1.
Nelly Suryani1.
Ofa Suzanti Betha1.
Zilhadia1.
Sofa Fajriah2.
Abdi Wira Septama2.
Maulina Handayani3.
Herdini4 Department of Pharmacy.
Faculty of Health Sciences.
Syarif Hidayatullah State Islamic University.
Jakarta.
Indonesia Chemistry Laboratory of the National Research and Innovation Agency (BRIN) in Serpong.
Indonesia Department of Nursing.
Faculty of Health and Sciences.
Syarif Hidayatullah State Islamic University.
Jakarta.
Indonesia Department of Pharmacy.
Faculty of Mathematics and Natural Sciences.
Institute Sains dan Teknologi Nasional.
Jakarta.
Indonesia, 12630 *Corresponding author: sabrina@uinjkt.
Received: 30 December 2024.
Accepted: 25 June 2025 Abstract: Centella asiatica (L.
) Urb.
is a plant known for its potential in scar treatment due to the presence of asiaticoside, a compound capable of promoting skin cell tissue repair.
However, the large molecular size of asiaticoside hinders its penetration through the skin.
This study aims to evaluate the effect of gelatin and propylene glycol on the transdermal penetration of asiaticoside from a gel formulation containing Centella asiatica leaf Four different formulations were tested: a control (F1, without gelatin or propylene glyco.
one with 15% propylene glycol (F.
one with 4% gelatin (F.
and one with 4% gelatin and 15% propylene glycol (F.
The physical characteristics of the formulations were assessed using several parameters: organoleptic properties, pH, homogeneity, centrifugation, spreadability, viscosity, and rheological behaviour.
Penetration studies were performed using a Franz Diffusion Cell with a Whatman No.
1 membrane .
re-coated with Spangler solutio.
for 360 minutes.
The penetration data were analyzed using Liquid ChromatographyAeTandem Mass Spectrometry (LCAeMS/MS) with a C18 BEH column .
1 y 50 mm.
8 m particle siz.
The results showed that each formulation exhibited distinct characteristics.
The study findings indicated that both gelatin and propylene glycol, as well as their combination, significantly influenced the penetration of asiaticoside in the gel formulation.
Propylene glycol, functioning as a penetration enhancer, was found to increase the penetration of asiaticoside in both gelatin-based and liquid formulations.
Keywords: Asiaticoside.
Centella asiatica (L.
Franz Diffusion Cell.
Gelatin.
Penetration.
Propylene Glycol.
DOI: 10.
15408/pbsj.
INTRODUCTION
Centella asiatica (L.
) Urb, commonly known as pegagan in Indonesia, is a plant that grows and spreads widely in tropical regions.
This plant has varying names and morphological forms across different regions in Indonesia and other countries.
The differences in morphology and growing locations affect its bioactive compound content.
Asiaticoside is one of the most abundant compounds in pegagan.
Other compounds found in pegagan include tannins, vellarin, hydrocotylin, carotenoids, centeloside, mineral salts, and others (Sutardi, 2.
Asiaticoside is a triterpenoid glycoside classified under the alphaamarin derivatives with sugar molecules .
lucose and rhamnos.
Asiaticoside has the ability to strengthen and enhance the repair of skin cells, making it widely used in topical products.
However, due to its molecular weight of 911.
1233 g/mol and the presence of the stratum corneum layer on the skin, the penetration of asiaticoside in topical applications is challenging (Li et al.
, 2.
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Vol.
Topical administration is one route of drug delivery through the skin, with gel being one of its Gel is a semi-solid dosage form made from small inorganic particles or large organic molecules dispersed in a liquid (Danimayostu et al.
, 2.
Gel formulations are popular due to their appealing characteristics, including a cooling sensation, high adhesion, non-stickiness, ease of water removal, ease of application, and good absorption (Hastuty et al.
, 2.
A critical component in gel formulations is the gelling agent.
Gelling agents are key components in the preparation of gels and are high molecular weight polymers that have multiple molecules cross-linked with the solvent molecules.
The choice of gelling agent significantly affects the form and stability of the gel.
Gelatin is one such gelling agent widely used in both food and non-food industries.
Gelatin is a polypeptide compound obtained through partial acid or base hydrolysis of collagen derived from animal bones and skin (Suseno & Roswiem, 2018.
Rauf et al.
, 2.
The presence of gelling agents can also aid in the delivery of drugs that are difficult to penetrate (Dahlizar et al.
, 2.
Based on the data, asiaticoside's penetration through the stratum corneum is challenging due to its high molecular weight, necessitating the use of a penetration enhancer.
Various penetration enhancers such as terpenes, alcohols, and surfactants are available (Dewi et al.
, 2.
Propylene glycol is one such enhancer classified as an alcohol.
Propylene glycol can improve the solubility of drug compounds and disrupt the extracellular lipid components in the stratum corneum, thereby enhancing the diffusion process (Priani et al.
, 2.
Given the background above, it is crucial to conduct research on the formulation of gel preparations containing asiaticoside from pegagan leaves, examining the impact of gelatin as a gelling agent and propylene glycol as a penetration enhancer.
Penetration testing will be conducted using a Franz Diffusion Cell with a Whattman No.
1 membrane coated with Spangler liquid, which mimics skin The concentration of penetrated asiaticoside will be measured using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) due to its specific and sensitive ability to measure compounds based on molecular weight (Astuti et al.
, 2.
This study addresses a relevant in the field of pharmaceutics and cosmeceuticals, specifically regarding gel formulations based on plant extracts to enhance the penetration and concentration of asiaticoside in the skin, due to its high molecular weight.
The approach involves the combination of a chemical penetration enhancer .
ropylene glyco.
and a gelling agent .
to facilitate dermal penetration, thereby improving bioavailability and ensuring therapeutic efficacy.
This contributes significantly to the development of more effective topical delivery systems.
METHODS
Preparation of the formulations were carried using a digital analytical balance (GH 202.
OGS.
Japa.
, an overhead stirrer (IKAA RW 20 Digita.
, a hot plate (IKAA CMAG HS.
, and an oven (Memmert Oven UN55.
German.
Characterization of the resulting formulations were performed using pH meter (Horiba F-52.
Japa.
, viscometer (IKAA Rotavisc MV), the asiaticoside and Centella asiatica (L.
) Urb Leaf extract gel was provided by the National Research and Innovation Agency.
Serpong.
Indonesia.
Gelatin (Making Cosmetics.
Snoqualmie United State.
, propylene glycol (Dow Chemical Pacific.
Singapor.
All others chemicals and solvents were of reagent grade and were obtained commercially, with majority from Wako Pure Chemical Industries.
Ltd.
Osaka.
Japan.
This study refers to the formulation of gel preparations with four variations to evaluate the effects of using a gelling agent .
and propylene glycol on the penetration of asiaticoside from pegagan leaf extract gels (Budi & Rahmawati, 2.
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1 Gel Formulation Table 1.
Formulation of Pegagan Leaf Extract Gel Material Function Pegagan leaf extract Active ingredient Gelatin Gelling agent Propylene Glycol Enhancer DMDM Hydantoin Preservative Aquadest Solvent Information* :
A F1: No gelling agent and no enhancer A F2: No gelling agent, with enhancer A F3: No enhancer, with gelling agent A F4: With gelling agent and enhance Ad 100 Formula (% w/.
i Ad 100 Ad 100 Ad 100 2 Gel Preparation Gelatin is dissolved in aquadest at a ratio of 1:20, as gelatin dissolves more readily in hot water.
Pegagan leaf extract is dissolved in aquadest as needed and added to the gelatin solution.
DMDM hydantoin, propylene glycol, and the remaining aquadest are then added to the gelatin solution.
The components of the formulation are mixed using a magnetic stirrer at 30AC to enhance the homogeneity of the The gel will form after being allowed to stand for a period of time (Rauf et al.
, 2.
3 Evaluation of Gel preparations Organoleptic Test The gel is visually inspected for consistency, odor, and color.
Typically, the gel should be clear and have a semi-solid consistency (Astuti et al.
, 2.
pH Test The pH of the gel is measured using a calibrated pH meter.
One gram of gel is dissolved in 10 times its volume of aquadest.
The gel is considered acceptable if its pH falls within the skin's pH range of 4.
5 Ae 5 (Astuti et al.
, 2.
Homogeneity Test Homogeneity is assessed by observing the clarity of the gel or the absence of coarse particles.
The gel is spread evenly on a glass plate and checked for the presence of coarse particles (Astuti et al.
, 2.
Centrifugation Centrifugation is performed to determine the stability of the gel.
The gel is subjected to centrifugation for 30 minutes at 5000 rpm, and phase separation is observed (Bayti et al.
, 2.
Spreadability Test The spreadability of the gel is assessed by placing 1 gram of the pegagan leaf extract gel on a mica sheet, which is then placed on graph paper.
Another mica sheet is placed on top, and the diameter of the spread gel is measured after applying a 50-gram weight for 1 minute.
The weight is increased to 100 grams, 150 grams, and 200 grams, and the diameter of the spread gel is recorded.
The test is conducted in triplicate (Senja & Renny, 2.
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Viscosity and Rheology Test The viscosity and rheology of the gel are measured using two devices: the Brookfield UL Adapter viscometer for formulations F1 and F2, and the IKA Rotavis .
eAev.
viscometer for formulations F3 and F4.
For F1 and F2, approximately 16 ml of gel is placed in a sample tube up to the spindle mark.
Measurements are taken at rotation speeds of 0.
3, 0.
6, 1.
5, 3, 6, 12, 30, and 60 rpm.
For F3 and F4, 100 grams of gel is placed in a beaker and measured using the IKA Rotavis .
eAev.
viscometer with spindle 11 at appropriate speeds.
A good viscosity range is 2000 Ae 4000 cps.
Rheological properties are determined by varying the rotation speeds (Senja & Renny, 2.
Flow properties are assessed based on the shear rate .
versus the force .
yne/cmA) (Ismayanti et al.
, 2.
4 Penetration Test The penetration of the gel is tested using a Franz Diffusion Cell with a 21 ml compartment filled with LCMS-grade aquadest, maintained at 37AC A 1AC, and stirred at 300 rpm.
Approximately 1 gram of gel is placed on a Whattman No.
1 membrane that has been soaked in Spangler solution for 15 minutes.
The membrane is weighed and placed between the donor and receptor compartments.
Samples are collected at 360 minutes .
using a syringe.
The concentration of asiaticoside in the samples is measured using LC-MS/MS.
5 Determination of Asiaticoside Content Using LC-MS/MS The asiaticoside content in the penetration samples is determined using LC-MS/MS with Multiple Reaction Monitoring (MRM) and an Acquity UPLCA C18 Waters BEH column .
1 x 50 mm.
The mobile phase consists of water, acetonitrile, and 0.
1% formic acid.
Analysis is conducted with a retention time of 17 minutes.
Asiaticoside is identified based on its target molecular weight of m/z 976.
4 ([M NH.
) as the parent ion and m/z 453.
4 as the product ion (Gajbhiye et al.
RESULTS AND DISCUSSION
Organoleptic Test The organoleptic test is conducted to assess the characteristics of the formulation, such as color, odor, and texture.
According to Table 1, the observations show that all formulations have a deep green color and a distinctive aroma characteristic of pegagan leaf extract.
The gel base exhibits a yellowish, transparent color due to the natural color of gelatin.
The color and odor changes are attributed to the addition of pegagan leaf extract at a concentration of 5%.
The concentration of the extract influences the intensity of the color.
higher concentrations result in a more intense color (Prasongko et al.
, 2.
Table 2.
Organoleptic Properties of Pegagan Leaf Extract Gel Formula Color Odor Texture Deep green Specific Pegagan Leaf Extract Liquid Deep green Specific Pegagan Leaf Extract Liquid Deep green Specific Pegagan Leaf Extract Viscous Deep green Specific Pegagan Leaf Extract Viscous Information * :
A F1: No gelling agent and no enhancer A F2: No gelling agent, with enhancer A F3: No enhancer, with gelling agent A F4: With gelling agent and enhance 46 | S a b r i n a e t a l Pharmaceutical and Biomedical Sciences Journal, 2025.
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In addition to having the same color and odor, the formulations are distinguished by their texture, resulting in two types of formulations: F1 and F2 are liquid, while F3 and F4 are gels.
This difference is due to the presence of the gelling agent, gelatin, in F3 and F4 at a concentration of 4%.
Generally, gels form through the cross-linking of polymer chains, which leads to the formation of a helical structure due to hydrogen bonding, ionic interactions, and rigidity, creating a continuous three-dimensional mass (Nugrahaningsih et al.
, 2.
Gelatin gels form through the expansion of gelatin molecules during heating, which causes the breaking of gelatin molecular bonds and the binding of free liquid to form a gel (Agustini et al.
, 2.
PH Test The pH test is conducted to determine the acidity level of a formulation.
The acidity of the formulation is a crucial aspect of evaluation to ensure both safety and comfort during use (Agustiani et al.
, 2.
A gel with a pH that is too acidic can cause skin irritation, while a gel with a pH that is too alkaline can lead to skin dryness.
Therefore, the formulation should have a pH range compliant with regulations, typically around pH 4.
5 Ae 6.
5 (Mursal et al.
, 2.
Table 3.
pH of Pegagan Leaf Extract Gel .
Formula Information* :
A F1: No gelling agent and no enhancer A F2: No gelling agent, with enhancer A F3: No enhancer, with gelling agent A F4: With gelling agent and enhance 92 A 0.
91A 0.
26 A 0.
32 A 0.
The pH of the formulations was measured by dissolving 1 gram of gel in 10 ml of solvent, then measuring with a calibrated pH meter.
As shown in Table 2, the pH of F1 and F2 is approximately 4.
while F3 and F4 have a pH around 5.
The difference in pH is due to the inclusion of gelatin as a gelling agent.
Gelatin has a pH range of 4.
8 Ae 9.
0, so its addition to the formulation increases the pH.
The acidity or pH of gelatin is influenced by the solvent and the method used in its preparation (Elmitra.
Homogeneity Test The homogeneity test is conducted by visually inspecting the formulation.
The test involves placing the formulation between two glass plates.
The purpose of this test is to ensure that all components are uniformly mixed in the gel formulation.
Observations of the pegagan leaf extract gel show that there are almost no visible coarse particles, indicating good dispersion or dissolution of the extract.
The even distribution of color also serves as an indicator of the formulationAos homogeneity.
These results suggest that the pegagan leaf extract gel meets the criteria for homogeneity (Astuti et al.
, 2.
Viscosity and Rheology Test Rheological testing determines the flow properties of a solution or semisolid by varying the rotational speed .
to obtain different viscosity values.
Flow properties are determined through the shear rate .
versus shear stress .
yne/cmA) curve (Sulastri & Zamzam, 2.
F1 and F2 exhibit Newtonian flow properties (Figure .
, this is indicated by a linear curve relationship between shear stress and shear Newtonian flow properties are characterized by a constant viscosity (Iswandana & Sihombing, 47 | S a b r i n a e t a l Pharmaceutical and Biomedical Sciences Journal, 2025.
Vol.
In contrast.
F3 and F4 show thixotropic pseudoplastic flow properties.
This is indicated by a decrease in viscosity .
at each shear rate from the descending curve compared to the ascending curve.
This behavior may result from structural breakdown that does not quickly reform even when the applied pressure decreases or is removed (Indrawati & Sofia, 2.
Figure 1.
Rheology Curve of Pegagan Leaf Extract Gel F1 (No gelling agent and enhance.
F2 (No gelling agent, with enhance.
F3 (No enhancer, withgelling agen.
F4 (With gelling agent and enhance.
The flow properties of the four gel formulations are influenced by their viscosity.
Viscosity testing was conducted using a Brookfield UL Adapter viscometer for F1 and F2, and a Rotavis viscometer for F3 and F4.
The formulations were placed in a container up to the spindle's immersion mark, and the rotational speed .
of the spindle was adjusted.
Table 4.
Viscosity of Pegagan Leaf Extract Gel Formulation Information* :
A F1: No gelling agent and no enhancer A F2: No gelling agent, with enhancer A F3: No enhancer, with gelling agent A F4: With gelling agent and enhance Viscosity .
Based on Table 3, the viscosity tests indicate that all four formulations have different viscosities due to the absence of a gelling agent .
in F1 and F2, resulting in lower viscosity and a colloidal form.
In contrast.
F3 and F4 contain gelatin, which leads to higher viscosity values.
The standard viscosity range for gel formulations is between 6000 Ae 50000 cP (Hidayanti et al.
, 2.
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Figure 2.
Viscosity Curve of Pegagan Leaf Extract Gel The presence of gelatin as a gelling agent significantly affects the viscosity of the formulation.
The concentration of gelatin used impacts the viscosity level.
higher concentrations of gelatin result in increased gel viscosity (Sulastri & Chaerunisaa, 2.
The use of propylene glycol also influences the viscosity of the formulation.
Gel formation occurs through the cross-linking of polymer chains, resulting in a helical structure due to hydrogen bonds, ionic interactions, and rigidity, thus forming a continuous three-dimensional mass.
As shown in Figure 2.
F4 exhibits higher viscosity than F3, which can be attributed to the presence of propylene glycol, leading to an increase in the viscosity of the Centrifugation Test The stability of a formulation during storage is a critical factor influencing its quality, necessitating centrifugation tests.
The effect of gravitational force is used to evaluate the stability of the gel.
The test involves observing phase separation in the formulation that has been centrifuged for 30 minutes at a rotational speed of 5000 rpm (Bayti et al.
, 2.
Table 5.
Centrifugation Test of Pegagan Leaf Extract Gel Formula Information* :
A F1: No gelling agent and no enhancer A F2: No gelling agent, with enhancer A F3: No enhancer, with gelling agent A F4: With gelling agent and enhance Separation Occurs Separation Occurs No Separation Occurs No Separation Occurs Based on Table 4, the test results indicate that F1 and F2 showed phase separation, evidenced by the presence of sediment or brownish particles.
This sediment is likely due to extracts that were not completely dissolved or well-dispersed in the gel formulations.
F1 and F2, which have a liquid consistency, allowed undissolved particles to settle quickly.
In contrast.
F3 and F4 did not exhibit any sediment after testing, indicating better stability.
The stability of F3 and F4 can be attributed to the presence of gelatin and propylene glycol, which enhance solubility and increase viscosity.
This results in improved dispersion and a reduced rate of sedimentation (Bayti et al.
, 2.
Spreadability Test The spreadability test is a physical evaluation conducted to assess the ability of a formulation to spread by observing changes in the gel size before and after applying a predetermined weight.
A good spreadability range for semisolid formulations is typically between 5 and 7 cm (Sulastri and Chaerunisaa, 2.
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Tabel 6.
Spreadability of Pegagan Leaf Extract Gel .
Weight .
Information* :
A F3: No enhancer, with gelling agent A F4: With gelling agent and enhance Diameter .
7 A 0.
6 A 0.
4 A 0.
6 A 0.
4 A 0.
3 A 0.
9 A 0.
1 A 0.
Based on Table 5.
F3 exhibits a larger spread diameter compared to F4.
The difference in spread diameter between F3 and F4 is influenced by the viscosity of the formulation.
higher viscosity results in a smaller spread diameter.
The presence of propylene glycol in F4 increases its viscosity compared to F3, leading to a lower spreadability for F4.
Conversely.
F1 and F2 have lower viscosity, resulting in higher spreadability.
The spreadability range can impact the release of the active ingredient and the comfort during application (Syam & Marini, 2.
Penetration Test In vitro penetration testing of gel formulations aims to determine the concentration of asiaticoside that penetrates through the skin over a specified period.
The test is conducted using a Franz diffusion cell, which operates on the principle of placing a membrane between the donor and receptor compartments.
Typically of membranes used can be animal skin or synthetic.
However, this test uses Whatman No.
membrane coated with Spangler's liquid.
The use of a Spangler-coated membrane simulates a skin-like barrier, although it is not as complex.
Initially, the weight of the Whattman No.
1 membrane is measured before and after soaking in SpanglerAos liquid to determine the percentage of absorbed liquid.
The membrane's uniformity is considered acceptable if the absorbed Spangler's liquid percentage falls within the range of 102.
19% to 131.
Based on Table 6, the weight of the membrane after soaking meets the required standards (Astuti et al.
, 2.
Table 7.
Weight Uniformity of Whatman No.
1 Membrane Formula Weight Membran Soaking .
Before After Information*:
A F1: No gelling agent and no enhancer A F2: No gelling agent, with enhancer A F3: No enhancer, with gelling agent A F4: With gelling agent and enhance SpanglerAos Liquid Entrapped (% w/.
Penetration testing was conducted using 1 gram of gel formulation applied to the donor compartment.
Approximately 21 ml of LC-MS/MS grade water was used as the receptor fluid in the receptor LC-MS/MS grade water was selected for its high quality, which meets the required standards based on physical and chemical parameters, such as Total Dissolved Solids (TDS), pH, and electrical conductivity (Ikhwanudin et al.
, 2.
The test was performed at a temperature of 37AC A 1AC, with a magnetic stirrer set at 300 rpm.
The temperature was controlled to match normal human body conditions, as temperature can affect the penetration of substances (Sugiyati et al.
, 2.
The magnetic stirrer ensures uniform distribution of the penetrated substance within the compartment (Halim et al.
, 2.
Samples of 2 ml were collected at the 360 minute using a syringe, then transferred to a vial for concentration analysis using LC-MS/MS.
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Based on the penetration test results.
F1 and F2 exhibit higher penetration levels compared to F3 and F4.
This is due to the lower viscosity of F1 and F2, which allows the active ingredient to more easily permeate the membrane.
Conversely.
F3 and F4 have higher viscosities due to the presence of gelatin, which forms a more viscous gel structure.
In drug delivery systems, gel functions as a membrane that regulates the gradual release of active ingredients (Budiatin et al.
, 2.
, and the viscosity of the formulation, influenced by the concentration of the gelling agent, affects the penetration level (Azmi et , 2.
The higher viscosity in F3 and F4 inhibits the penetration of the active ingredient but provides a better gel consistency (Sulastri & Chaerunisaa, 2.
Additionally, if we compare the liquid (F1 and F.
and gel formulations (F3 and F.
we can observed that F2 and F4 demonstrates greater penetration compared to F1 and F3 due to the presence of propylene glycol as an enhancer.
Propylene glycol increases penetration by disrupting the intracellular lipid matrix, thereby facilitating the active ingredient's passage through the stratum corneum layer (Mulyana et al.
, 2016.
Qisti et al.
, 2.
CONCLUSION
Based on the conducted research, it can be concluded that the use of gelatin and propylene glycol in the formulation of Centella asiatica (L.
) Urb extract gel affects the characteristics of the gel, including organoleptic properties, pH, homogeneity, spreadability, viscosity, and rheology.
Gelatin has a more significant impact, leading to notable differences between formulas, particularly between those with gelatin and those without.
The use of gelatin and propylene glycol influences the penetration of Centella asiatica (L.
) Urb extract gel.
Specifically, propylene glycol enhances penetration due to its role as a penetration enhancer.
CONFLICT OF INTEREST
The authors have no conflicts of interest regarding this investigation.
ACKNOWLEDGMENTS
The authors would like to express their gratitude to the Chemistry Laboratory of the National Research and Innovation Agency (BRIN).
Serpong.
Indonesia.
and Research Center of Syarif Hidayatullah State Islamic University Jakarta Indonesia for their assistance and funding support for this research.
REFERENCES