Compatibility study of hydroxypropylmethylcellulose films containing zidovudine and lamivudine using thermal analysis and infrared spectroscopy

摘要

Zidovudine (AZT) and lamivudine (3TC) are drugs commonly used in the treatment of acquired immune deficiency syndrome; however, these drugs have low bioavailability and short biological half-life. These factors contribute to the emergence of various side effects and lack of patient adherence to treatment. Therefore, the study of drug delivery systems is of extreme interest. In this context, this study intends to develop hydroxypropylmethylcellulose films (HPMC) containing AZT and films containing 3TC, and assess the existence of drug/polymer interactions by means of thermal analysis techniques [differential scanning calorimetry (DSC) and thermogravimetry (TG)/derivative TG (DTG)], Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD), contributing to the optimization of antiretroviral therapy. The films produced showed drying uniformity and drug distribution. DSC curves indicated that these drugs may be in an amorphous form dispersed in the polymeric matrix. Thermal decomposition profiles obtained in the TG/DTG studies of films containing drugs showed similarities with the curves of their respective physical mixtures. The FTIR spectra showed the characteristic bands conservation of AZT and 3TC isolated in the films with drugs. The results indicate that these drugs did not undergo a process of degradation or chemical interaction with the polymer that would lead to the modification or alteration of their chemical structures. XRD studies confirmed that these drugs were homogenously dispersed in the polymeric matrix. These results also showed that there was no drug/polymer incompatibility in HPMC films.