The Calamansi peels were collected from the industries manufacturing Calamansi juice in the city, and a few samples were authenticated by the Quarantine Division of the Department of Agriculture, Zamboanga City. The peels were washed and dried to remove adhering liquid.

The cleaned calamansi peels were peeled, and the albedo portion was separated and cut into small pieces. These pieces were then dried in an oven at 50 °C for 48 h. This temperature serves as a “stress test” to identify immediate potential for phase separation, chemical oxidation of essential oils, or rapid microbial growth in the aqueous gel matrices. The dried sample was ground in a dry blender, and the resulting powder was sieved to the desired size. Cellulose extraction was performed using an alkaline treatment followed by bleaching (Zain et al., 2015).

A 50 g sample of dried albedo powder was weighed and transferred into a round-bottom flask. An alkaline solution (4% wt NaOH) was added, and the treatment was performed under reflux at 100–120 °C for 2 h. The obtained mixture was filtered and washed several times with distilled water to remove lignin and hemicellulose that had dissolved in the solution. The resultant fiber was dried before bleaching. Bleaching treatment was performed under reflux at 110–130 °C for 4 h after adding 60 g of fiber to 400 milliliters (mL) of each solution: 1.7% NaClO2, acetic buffer, and distilled water. The mixture was allowed to cool, then filtered and washed with distilled water until white cellulose was obtained. The cellulose obtained was dried by using a freeze dryer at −39 °C for 24 h. The powdered cellulose was stored in an air-tight container until further use.

Iodine Test. Add a pinch of the cellulose powder to a watch glass. Add 2–3 drops of Lugol’s Iodine to the cellulose powder. A blue-black color was observed, which is indicative of the presence of polysaccharides.

The Ionotropic Gelation Technique was used to prepare cellulose microbeads from calamansi peels. A mixture of sodium alginate and carrageenan (60:40 w/w, 2% w/v) was dissolved in deionized water under magnetic stirring for ~30 min at 60 °C, then cooled to ~37 °C. An accurately weighed quantity of cellulose powder was added to the mixture, which was then thoroughly mixed with a magnetic stirrer at 400 rpm. For the formation of microbeads, 50 mL of this solution was extruded dropwise from a needle into 100 mL of 2% calcium chloride solution, and the mixture was stirred at 100 rpm for 10 min. The microbeads were separated from the hardening bath and suspended in a 2% w/v sodium alginate solution for coating. The coated microbeads were formed by taking the microbeads into a plastic pipette and dropping them into a hardening bath of calcium chloride concentration (1 mM) in water. A 1 mM concentration for the hardening bath was optimized to ensure adequate ionic crosslinking of the sodium alginate-coated cellulose without inducing excessive brittleness or “over-curing, “which can occur at higher concentrations. This specific molarity facilitates a controlled gelation rate, which is essential for maintaining the internal porous structure of the calamansi-derived cellulose (Lee and Mooney, 2012). After a few minutes of curing, the coated microbeads were removed from the hardening bath, washed with deionized water, and placed in petri dishes for “protection” and “conservation.” Finally, the coated microbeads will be dried (dehydrated) for 24 h at room temperature (Badarinath et al., 2010; Trif et al., 2019).

Their chemical functionalities and physical properties determine the performance of cellulose microbeads in specific applications. For characterization, the general appearance, morphology, particle size, flow properties, and stability studies will be determined. The methods are derived from Badarinath et al. (2010).

General appearance: The morphological characterization, which includes shape, color, presence or absence of odor, and surface texture of the microbeads, will be determined.

Morphology: The physical surface and morphology of the microbeads will be determined using a scanning electron microscope. Microbead samples will be sputtered with gold and scanned at an accelerating voltage of 15 Kv.

Particle size: Particle size distribution will be determined by sieve analysis on a mechanical sieve shaker using different meshes (12, 16, 20, and 30) per the American Society for Testing and Materials.

Flow properties: The angle of repose will be determined by the funnel method.

The microbeads will be allowed to ow through the funnel freely onto the surface. The cone’s diameter will be measured, and the angle of repose will be calculated using the equation. An angle of repose of 46 or above indicates poor flow properties.

where tan θ is angle of repose, h is height of the cone, r is radius of the cone base.

Stability test: A small number of biodegradable microbeads were placed in a hot-air oven at 45 °C for 8 weeks (60 days), with three time points (2nd, 4th, and 8th weeks). The bead size and form will be observed through the stability test.

Determination of clarity, color, and odor: Visual observation against a white background will be done for clarity and color of the prepared formulation, and the odor will be smelled.

All preservatives, propylene glycol, and sodium lauryl sulphate will be dissolved in a sufficient quantity of water. To the solution, Carbopol will be added slowly with constant stirring until a gel-like dispersion is obtained. Five grams of calamansi microbeads will be added slowly until a gel-like consistency is achieved. Then, finally, triethanolamine will be added.

Ingredients	Quantity (%)
Carbopol 940	2
Methyl paraben	0.1
Propyl paraben	2
Triethanolamine	2
Propylene glycol	2
Sodium lauryl sulphate	2
Distilled water	Q.S
Calamansi microbeads	5 g

In the present study, the formulated hand sanitizer was evaluated under various parameters, as shown in Table 2. An attempt was made to create a hand sanitizer using alternative ingredients. The formulated product was smooth in texture, clear, crystal white in color, and gel-like in consistency. It also had a sweet or aromatic smell (see Figure 3). A digital pH meter was used to measure the pH of the hand sanitizer gels. The purpose of the investigation was to determine whether specific prepared formulations could be neutralized. To prevent skin irritation and inflammation, the optimal pH range for a topical dose form is between 4.0 and 7.0, which is the wide range of the skin’s pH15. With an average pH of 3.55, the pH readings.

in Table 2 indicated that the created formulation was slightly acidic. This might be due to the large portion of calamansi microbeads. According to reports, the neutral pH range is ideal for the growth of several harmful bacteria that can infect the skin.

On the other hand, if the pH level is somewhat acidic, normal ora is more likely to settle in the skin (Ali and Yosipovitch, 2013). Notably, an acidic pH environment (4.0–4.5) can facilitate attachment of normal ora to the skin (Lambers et al., 2006). Furthermore, it has been shown that the natural state of the skin’s surface has an average pH below 5.0, which is ideal for several critical dermal biological processes, including the formation of the lipid barrier and the homeostasis of the stratum corneum (Rippke et al., 2002; Parra and Paye, 2003).

Finally, the prepared hand sanitizer did not exhibit any color change or phase separation throughout the stability testing. Additionally, the products’ odors remained steady, and even after being heated during storage, their composition remained the same. This is because Carbopol 940, when used as a gelling agent has stable qualities that allow the resulting gel preparation to have good stability over time in storage (Astuti et al., 2017). Compared to hand sanitizer formulations, alcohol-based gel hand sanitizer is of high quality, extremely effective, and safer to use. Prepared gel hand sanitizers significantly improve hand hygiene and reduce the spread of bacteria among populations. We can use this hand sanitizer properly to maintain proper hand hygiene in the future. Furthermore, all the herbal plants used to make the hand sanitizer, and the blend of all extracts, had vigorous antibacterial activity against E. coli and P. aeruginosa. Coli, Klebsiella species, and S. aureus, S. The zones of inhibition for P. pyogenes and Dermatophyte were 7 ± 0.03, 7 ± 0.03, 8 ± 0.001, 7 ± 0.03, 6 ± 0.02, and 6 ± 0.01, respectively, 21. Ultimately, using naturally derived herbal hand sanitizers can be a viable substitute for chemically manufactured hand sanitizers that contain active silver nitrates. This is because people who prefer natural products might prefer herbal hand sanitizers, which are typically more affordable, effective, and environmentally friendly (Verma et al., 2023).

The prepared facial gel exfoliant was evaluated for homogeneity, appearance, pH, spreadability, extrudability, irritability, washability, and foamability, and subjected to stability testing shown in Table 3. The formulated product was determined to be white, homogeneous, and free of lumps (see Figure 4).

Using a digital pH meter, the gel’s pH was measured at 7.6. After applying a small amount of gel to one glass slide and placing another on top, 100 g of weight was added to the slide, and the time required for the gel to spread and the area measured were recorded. The area and quantity of gel on the glass slide indicate a spreadability efficiency of 103.80 g/s ± 12.898. Additionally, a small amount of gel was added to a collapsible tube, and the crimped end was tightly crimped. Following the removal of the cap, the average extrusion pressure was calculated from the weight (17.27 g/s ± 1.026) needed to extrude, the extrusion time, and the amount of gel extruded. Following the skin irritation test, the gel was determined to be non-irritating after the same quantity was applied to the skin and left for a short while. This indicates that the microbeads found in the product are a non-irritating ingredient according to clinical practice guidelines of the Japanese dermatological association (Katoh et al., 2019; Omichi et al., 2014). After applying a little amount of gel to the skin, it was rinsed with water. It was simple to wash at 29 ± 2.00 s. In addition, the foam remained stable when a small quantity of gel was shaken with water in a graduated measuring cylinder. Ultimately, after going through two independent stability tests, the created facial gel exfoliant demonstrated good stability. The manufactured herbal scrub was deemed satisfactory for skin application to promote healthy, glowing skin following rigorous examination of numerous parameters. The use of scrub gel, which enhances oxygen delivery to the entire skin surface, helps promote blood circulation. After using a scrub, the skin feels cleaner, softer, and more invigorated. Investigation also found that the polyherbal scrub gel performed well and remained stable at 45 °C. Scrub gel’s results indicate that it can be used on the skin to enhance health and brightness without any adverse effects. Among the numerous formulas tested, the F9 batch produced good results, with a good pH and viscosity, as well as improved skin-smoothing and spreading capabilities (Aglawe et al., 2019). Thus, it can be said that this scrub gel has fewer adverse effects and is highly helpful for oily skin types. In conclusion, the scrub gel was assessed against a range of criteria and found suitable for use on the skin to promote health and radiance without causing adverse reactions. It is intended to conduct in vivo experiments on the irritancy of the prepared scrub (Aglawe et al., 2019).