Aim The in vitro drug release profiles of metformin hydrochloride thermoplastic coated tablets and nifedipine thermoplastic coated tablets were studied. Methods By measuring the in vitro release profiles of the thermoplastic coated tablets of model drugs, the effects of membrane thickness, polyethylene glycol-1,500 (PEG1500) content, number of orifice, stirring speed, and release medium on the drug release were investigated, and the rule and mechanism of drug release were also analyzed by comparing with the osmotic pump tablets (OPTs). Results Thermoplastic coated tablets with single- or double-chamber construction performed the same function of controlling the drug release, operated under the same release mechanism (osmotic pressure drove the drug release), and exhibited the same release characteristics (zero-order release, unaffected by release medium, and stirring speed) and release rule (release rate was inversely proportional to the membrane thickness but proportional to the PEG1500 content) as compared with OPTs prepared by the common spray coating technology. Conclusion Thermoplastic coated tablets have the same release characteristics in vitro as OPTs. The new technology of thermoplastic coating can replace the spray coating technology of OPTs. This study provides theoretical basis and practical support for the industrialization and clinical application of thermoplastic coating technology.

Abstract Aim The in vivo pharmacokinetics of thermoplastic-coated tablets prepared by a new technology of thermoplastic coating in Beagle dogs were studied, and the correlation between in vitro release and in vivo absorption was analyzed. Methods The in vitro release profiles of metformin hydrochloride thermoplastic-coated tablets and nifedipine thermoplastic-coated tablets were investigated. The single-dose pharmacokinetic study of these tablets in Beagle dogs was performed, and the obtained results were separately compared with the data of conventional osmotic pump tablets reported in the literature. Results Metformin hydrochloride thermoplastic-coated tablets and nifedipine thermoplastic-coated tablets displayed controlled drug-release characteristics and had a good in vivo–in vitro correlation in Beagle dogs, respectively. The literature-compared results further demonstrated that both thermoplastic-coated tablets had release characteristics of osmotic pump tablets in vivo. Conclusion The thermoplastic-coated tablets could control drug release in vivo and it was further confirmed that the new thermoplastic coating technology could replace the spray coating of osmotic pump controlled-release tablets. This study provides a theoretical basis and practical support for the industrialization and clinical application of the new thermoplastic coating technology.