ABSTRACT
The addition of polymeric materials is often used to delay nucleation or crystal growth and maintain the high supersaturation of amorphous drugs. Therefore, this study aimed to investigate the impact of chitosan on the supersaturation behavior of drugs with a low recrystallization tendency and elucidate the mechanism of its crystallization inhibition in an aqueous solution. It was carried out using ritonavir (RTV) as a model of poorly water-soluble drugs categorized as class III of Taylor's classification, while chitosan was used as a polymer, and hypromellose (HPMC) was used for comparison. The inhibition of the nucleation and crystal growth of RTV by chitosan was examined by measuring the induction time. The interactions of RTV with chitosan and HPMC were evaluated by NMR measurements, FT-IR, and an in silico analysis. The results showed that the solubilities of amorphous RTV with and without HPMC were quite similar, while the amorphous solubility was significantly increased by the chitosan addition due to the solubilization effect. In the absence of the polymer, RTV started to precipitate after 30 min, indicating that it is a slow crystallizer. Chitosan and HPMC effectively inhibited the nucleation of RTV, as reflected by a 48-64-fold enhancement in the induction time. Furthermore, NMR, FT-IR, and in silico analysis demonstrated that the hydrogen bond interaction between the amine group of RTV and a proton of chitosan, as well as the carbonyl group of RTV and a proton of HPMC, was observed. This indicated that the hydrogen bond interaction between RTV and chitosan as well as HPMC can contribute to the crystallization inhibition and maintenance of RTV in a supersaturated state. Therefore, the addition of chitosan can delay nucleation, which is crucial for stabilizing supersaturated drug solutions, specifically for a drug with a low crystallization tendency.
ABSTRACT
This review aimed to evaluate the effectiveness of telemedicine as an intervention for patients with diabetes mellitus, considering blood glucose levels as the primary outcome. A comprehensive literature search was performed using the PubMed, Embase, Web of Science, and EBSCO databases. This narrative review covered randomized controlled trials published in English. The process of selecting studies adhered to the preferred reporting items for systematic reviews and meta-analyses guidelines. Nine studies were selected, and their data were analyzed and summarized. Five of the nine reviewed studies found that telemedicine counseling was effective in decreasing glycated hemoglobin A (HbA1c) levels in the blood. Due to methodological limitations, one study could not report HbA1c results, and two studies reported that telemedicine counseling did not lead to any significant changes in HbA1c levels. One study found that while HbA1c levels did not show a marked decrease, patients' treatment adherence and quality of life improved when telemedicine was combined with health counseling. Moreover, six studies found that telemedicine counseling was more effective than traditional counseling regarding secondary outcomes. The overall findings of this review suggest that telemedicine counseling is more effective than conventional counseling in achieving decreased blood glucose levels in patients with diabetes mellitus while increasing their treatment adherence and improving their quality of life.