Combination of Candlenut (Aleurites mollucana (L.) Wild) Oil and Celery (Apium graveolens) Extract Stimulates Hair Growth: Formulation and Activity Test of Spray Preparation

Hair serves both aesthetic and protective purposes. Alopecia (excessive hair loss) is frequently addressed with synthetic products that may cause adverse effects. Celery extract and candlenut oil are natural alternatives that can provide safer hair growth stimulation. This study aimed to assess the efficacy and safety of aerosol formulations of celery extract and candlenut oil. Aerosols of celery extract and candlenut oil were formulated at concentrations of 0.1% (F1), 0.5% (F2), and 1% (F3). The total flavonoid and phenolic contents of celery extract were evaluated colorimetrically. Fatty acid composition of candlenut oil was identified by gas chromatography-mass spectrometry (GC-MS). Acute dermal irritation test was performed by assessing erythema and edema on rabbits’ skin following spray application. The hair growth stimulating activity was assessed in vivo using rabbits. GC-MS analysis of candlenut oil revealed the main fatty acids as oleic acid (20.81%), linoleic acid (20.80%), and palmitic acid (20.79%), while celery extract contained flavonoids (50.41 ± 2.01 mg QE/g) and phenolic compounds (20.00 ± 0.01 mg GAE/g). Skin irritation test showed no erythema or edema on application of the aerosols, with a primary irritation index of 0.0 ± 0.0. The treatment groups exhibited a significant increase in hair growth compared to the control (p < 0.05), with F3 exhibiting the highest average hair growth rate of 0.64 mm/day. The results indicate that the combination of celery extract and candlenut oil can effectively stimulates hair growth without causing skin irritation, thereby substantiating its potential as a safe, natural alternative for alopecia treatment.