Determination of Shelf Life of Picralima nitida, Ciprofloxacin and Pefloxacin Using Bio-Based Concentration-activity Relationship Technique

Abstract

Aim: The shelf-life of Picralima nitida (herbal drug) and two orthodox drugs (ciprofloxacin, and pefloxacin) has been examined. Methodology: The stability studies were carried out using the bio-based concentration-activity relationship technique. Accelerated stability studies were applied on the basis of first-order degradation kinetics to determine the shelf-life of the drugs at different temperatures (45 – 70°C) and storage times (1, 2, 3 and 4 wks). Ciprofloxacin and pefloxacin were used as the comparative drugs for the estimation of the specifications for Picralima nitida. Their half-life (t1/2) and temperature coefficient (Q10) were also investigated. Results: All the drugs proved to be broad spectrum antibiotics and their concentrations were found to decrease with increase in storage time and temperature. Ciprofloxacin proved to be more active and stable than pefloxacin followed by Picralima nitida, but lost its activities against the organisms at the stressed condition, respectively. Picralima nitida retained its activity more at stressed condition because of the presence of active metabolites. The shelf-life (including the half-life) of ciprofloxacin was found to be 80.31 wks (533.08 wks) against Bacillus subtilis, pefloxacin was found to be 43.5 wks (288.75 wks) against Bacillus subtilis and 0.25 wks (1.65 wks) against Samonella typhi; Picralima nitida found to be 5.83 wks (38.72 wks) against Bacillus subtilis, 0.41 wks (2.69 wks) against Samonella typhi and 0.52 wks (3.45 wks) against Pseudomonas aureginosa. Conclusion: The shelf-life of Picralima nitida, ciprofloxacin, and pefloxacin were successfully determined using the bio-based concentration-activity relationship technique; ciprofloxacin and pefloxacin were also successfully used as the comparative drugs for the estimation of the specifications for Picralima nitida in treatment based on their inhibitory activity but varies with sensitivity activities on different bacteria (or micro-organisms).