In vitro Evaluation of Pharmaceutical Stability of Repackaged Chlorpromazine Hydrochloride Tablets in Sri Lankan Health Setting.

Abstract

Background: Ensuring the stability of pharmaceutical repackaged products is critical, especially in medications, that have the potential degradation against light and oxygen, like chlorpromazine (CPZ). This study may contribute to preserving the stability of repacked CPZ tablets throughout the intended period by evaluating commonly used repackaging materials in Sri Lanka. Objective: To evaluate the impact of different repackaging materials on the stability of chlorpromazine hydrochloride tablets over a one-month period Methods: Randomly selected baseline sample (BLS) tablets from an unopened container were subjected to test the weight variation, hardness, friability, disintegration, dissolution, and assay according to British Pharmacopeia (BP) 2022 at the point of collection. Then eight out of ten samples from the remaining tablets were repacked pairwise with an amber-colored glass bottle (B2, C2), Low-Density Polyethylene (LDPE) bag (B3, C3), paper bag (B4, C4), and Dose Administration Aid (DAA) (B5, C5). The other two samples were stored in the original container (B1, C1) to use as control samples (CS). All samples were stored for 30 days below 30℃. After 15 days (B series) and 30 days (C series), the same tests were performed. Results were analyzed by independent sample t-test using SPSS version 25.0. Results: All the samples complied with the BP, except the hardness test for B4 and C4. B1 and C1 have not shown any significant difference compared to the BLS. B3 and C3 gave significantly different results for the tests carried out except for the hardness test compared to the BLS. B5 showed a significant difference in the dissolution test (p=0.043) and C5 in the disintegration (p<0.001) and dissolution tests (p<0.001) compared to the BLS. B2 did not show significant differences for the tests compared to the BLS or CS. C2 exhibited a significant difference in the dissolution test (p=0.001) when compared to the BLS and also in both the dissolution test (p=0.010) and assay (p=0.017) when compared to the CS. Conclusion: Repackaging materials have a discernible impact on the stability of CPZ. However, when stored at temperatures below 30°C for 30 days, they can retain and release the active ingredient within the acceptable range.