Introduction: The Sahastara remedy is a Thai traditional medicine which has long been used for muscle and joint pain treatment. It has been reported to be anti-inflammatory drug, so it was developed in the form of ethanolic extract capsule. Thus, stability of the extract capsule should be studied to obtain data for clinical study. This study was to investigate the stability of nitric oxide production inhibition activity and piperine content of Sahastara remedy ethanolic extract capsules. Method: The Sahastara remedy was extracted with 95% ethanol. The extract was filled in capsule No.0 (sized 500 mg) to contain 100 mg of Sahastara remedy ethanolic extract. The capsules were kept in accelerated conditions (40 C ± 75% Rh) for 180 days. Capsules were sampling on 15, 30, 60, 90, 120, 150 and 180 days. The nitric oxide production inhibition activity was determined to assess the biological activity of Sahastara remedy ethanolic extract capsules. The piperine content was determined by high performance liquid chromatography to assess chemical content in Sahastara remedy ethanolic extract capsules. The results at different time intervals were compared with baseline (Day 0). Results: IC50 of nitric oxide production inhibition of capsule was 2.56 ± 0.81 µg/mL at baseline (Day 0). There is no significant difference at each time interval when compared to baseline data with p > 0.05. Piperine content was 24.35 ± 0.21 mg/capsule at baseline (Day 0). The piperine content at each time interval also showed no significant difference when compared to baseline. Discussion and Conclusion: The Sahastara remedy ethanolic extract capsules was stable at room temperature because its biological activity and chemical content did not change when it was kept in accelerated condition. It is assumed that the Sahastara remedy ethanolic extract capsules could be stored at room temperature for at least 2 years without losing the nitric oxide production inhibitory activity and piperine content. It is thus appropriate to be used in clinical study.
Kanokkangsadal et al. (2018) studied this question.