Investigation of pH Changes in Equisetum arvense Gel Formulations

Introduction. Equisetum arvense (L.), commonly known as horsetail, is used for several medicinal purposes including wound healing, strengthening of bones, teeth, nails and hair. The topical application of gels to pathological sites offers a great advantage by providing faster release of drug directly to site of action [1,2]. The surface of healthy human skin maintains an acidic pH (typically between 4 and 6), which is essential for preserving the integrity of the stratum corneum and maintaining a stable skin microbiome. Therefore, it is important to use topical products that do not disturb the natural skin pH balance [3]. Materials and methods. Gels were prepared using methyl cellulose as gelling agents, E. arvense (L.) extract 11% and distilled water. All the materials were mixed well and the resulting gels were left in the refrigerator overnight. The pH of gels was measured using a calibrated pH meter. Before each measurement the pH-meter was standardized with buffer solutions (pH 7.0) to ensure accuracy. Results were statistically processed by using SPSS version 30.0. Results and discussion. The results showed that the pH of the Equisetum arvense gel remained stable throughout the study period. After the first month, the pH value was 7.17.While at the end of the study (after 2 months), the pH of the gel was measured at 7.18. These results indicate that the E. arvense formulation has good pH stability. Statistical analysis also indicated no significant differences between months (p=1.000, when the level of statistical significance is p <0.05). Conclusions. The Equisetum arvense gel formulation with methyl cellulose maintained a nearly constant pH during the observation period, showing no significant fluctuations between measurements. This stability indicates that the formulation is chemically stable and that there is no visible degradation or interaction of ingredients over time.