Development and Validation of A HPLC-UV Method for Dissolution Testing of Ciclosporin: Its Application to The Measurement of Brand and Generic Versions from Different Countries

Ciclosporin is used as an immunosuppressant in post-organ transplantation. Recently, many questions have been raised about using generic substitutes, especially with narrow therapeutic index drugs (NTIDs). In this study, a simple high-performance liquid chromatography (HPLC) method was developed, validated and applied to detection ciclosporin in dissolution testing. Seven ciclosporin products (gelatin capsules) were included in this study, obtained from Columbia (C), Egypt (E), India (I), Jordan (J), Pakistan (P), Saudi Arabia (S), and Turkey (T). The dissolution test was done for all capsules. The Conditions were as follows: 500 ml deionized water as the medium in apparatus 2 (Pharmatest, Germany), temperature 37.5 ± 0.5°C; 50 rev/min, sampling times were 5, 10, 15, 30, 60 and 90 min with 5 ml for each sample. HPLC separation was done by a C18 column, 5 μm, (4.6 × 250 mm, ACE 5) held at 50 ± 0.3°C. Analytes were isocratically eluted at 0.7 ml/min with acetonitrile and water (70+30%) and 0.03% trifluoroacetic acid, over the 25-min run time. The intra-day and inter-day imprecision for ciclosporin across the standard range was <5% and <4%, respectively. The accuracy of the assay was within ± 13% of the true value at standard curve concentrations range from 0.1 to 2 mg/ml of ciclosporin. The lower and the upper limit of detection were 0.001 mg/ ml and 2 mg/ml of ciclosporin, respectively. All brands (S, T, P, J, E) and one generic (C) showed more than 80% of ciclosporin after 90 min (90.3, 100, 90.4, 82.7, 81.4 and 90.6%) respectively. One generic (I), showed less than the minimum percentage of labeled amount, 69.1%. Relative to the brand (T), statistical analysis showed significant differences (P<0.0001) of the mean percentage content between brand and generic. The 95% confidence interval range for the brands (E, J, P, and S) was (72.2-91.8), (73.4-93.3), (80.2-101.9), and (80.1-101.8), respectively, and (80.3-102.1), and (61.3-77.9) for the generic (C) and (I) respectively. Based on these results, we conclude that some of the ciclosporin preparations do not contain the exact mass labeled and the majority contained as yet unidentified impurities.