Impact of illegal trade on the quality of epoetin alfa in Thailand

Abstract

Background: Reports from the World Health Organization have suggested that counterfeit medicines pose a serious problem in developing countries. An investigation of anti-erythropoietin antibody-mediated pure red cell aplasia in Thailand found evidence of drug smuggling, which may have serious safety implications.

Objective: This study assessed the authenticity and quality of epoetin alfa samples in Thailand.

Methods: Samples of epoetin alfa-prefilled syringes were collected from the pharmacies at 2 major hospitals (62 samples), 8 retail pharmacies (41 samples), and Thai authorities (30 samples confiscated from smugglers at 2 airports, and 6 samples from a condominium used by smugglers). These samples were tested against the European Union Pharmacopeia specifications for aggregate content in epoetins of <2%. The integrity of epoetin alfa distribution channels, coldchain processes (maintenance at 2 degrees C-8 degrees C), primary and secondary packaging components (eg, batch number, expiration date, appearance, letter size), and company's confidential features (eg, nature of the ink, type and quality of the paper, other covered features) were also investigated. The main outcome measures were protein aggregate content, determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting; and isoform distribution, assessed by isoelectric focusing and Western blotting.

Results: Epoetin alfa samples obtained from the company's cold-chain and authorized distribution channels met all quality standards, as did all epoetin alfa samples obtained from the hospital pharmacies. However, evidence showed that some samples were being smuggled or sold illegally through certain unauthorized retail pharmacies. The epoetin alfa samples obtained from both airports and the condominium were stored improperly at room temperature. Aggregate levels exceeded the specification of <2% in 11 samples from 2 of the retail pharmacies (range, 1.2%-3.1%), 15 samples from the Dongmuang Airport (range, 2.2%-17.0%), and all 6 samples from the condominium (range, 10.5%-19.8%). All samples from the 2 hospitals, 8 retail pharmacies, and Suvarnabhumi Airport had the authentic 6 isoform bands. Samples from Dongmuang Airport and the condominium appeared to have the 6 characteristic bands, but positive confirmation was difficult because of band smearing caused by a high level of aggregates. All features of primary and secondary packaging were found to be authentic.

Conclusions: This investigation found evidence that some epoetin alfa samples were smuggled into Thailand without proper cold chain, contained high levels of protein aggregates, and were sold illegally through certain retail pharmacies. The Thai authorities have intervened to stop such unauthorized products from reaching patients. Strenuous efforts must be made to prevent illegal cross-border smuggling of biopharmaceuticals without proper cold chain because of the serious safety implications for patients in developing countries.