Rules and characteristics of crystallization inhibition of cellulose polymers against drugs in supersaturated states / 药学学报

This study aims to explore the characteristics of crystallization inhibition by cellulose polymers at the supersaturated states of drugs. The study was performed by simulating supersaturated process and preparing supersaturated drug solid, and was carried out by measuring the content of drugs at different time points using dissolution apparatus. The types, amounts, ionic intensity and viscosity of cellulose polymers were examined to assess the crystallization inhibition effect on BCS II class drug indomethacin. HPMC E15 exhibited the strongest crystallization inhibition effect. The more added, more obvious crystallization suppression was observed against indomethacin. The decrease in viscosity and increase in ionic intensity led to an enhanced inhibition. The research provides a scientific guide for the crystallization inhibition of supersaturated drug by cellulose polymers.

Comparison of the properties of curcumin solid dispersions prepared by different technologies / 中国药学杂志

OBJECTIVE: To prepare curcumin solid dispersions by different preparation technologies and compare their properties. METHODS: Curcumin/poloxamer 407 solid dispersions were prepared by freeze-drying, co-precipitation and microwave/quench cooling methods, respectively. Internal properties of obtained solid dispersion were analyzed by SEM, DSC, XRD and FT-IR. The improvement effect on the insolubility of curcumin by making it into solid dispersions by different technologies was characterized by dissolution and solubility experiments. RESULTS: Curcumin was dispersed in solid dispersions in micro-crystal form. Compared with other technologies, microwave/quench cooling method could significantly improve the solubility and dissolution of insoluble curcumin. CONCLUSION: The study provides reference for choice of applicable production technology for solid dispersions of insoluble Chinese traditional medicine curcumin.

Research on the rules of crystallization inhibition of cellulose polymers against supersaturated drugs by solubility test / 中国药学杂志

OBJECTIVE: To explore the characteristics of crystallization inhibition by cellulose polymers against supersaturated drugs. METHODS: The biopharmaceutics classification system(BCS) II class drug indometacin was selected as the model drug.Supersaturated amorphous drug solid was prepared and the solubility of indometacin was measured. The types, added amounts, ionic intensity and viscosity of cellulose polymers were employed as influential factors to assess the crystallization inhibition effect of polymers against indometacin. RESULTS: HPMC E15 displayed the strongest crystallization inhibition effect. The crystallization inhibition was enhanced by adding larger amount of polymers, decreasing the viscosity of polymers and increasing the ionic intensity. CONCLUSION: The study is helpful to clarify the profiles that cellulose polymers inhibit the crystallization of drugs in supersaturated states. This research may provide scientific guide for the practical application of cellulose polymers for drug crystallization.

Application of microwave irradiation technology to the field of pharmaceutics / 药学学报

Microwaves can be directly transformed into heat inside materials because of their ability of penetrating into any substance. The degree that materials are heated depends on their dielectric properties. Materials with high dielectric loss are more easily to reach a resonant state by microwaves field, then microwaves can be absorbed efficiently. Microwave irradiation technique with the unique heating mechanisms could induce drug-polymer interaction and change the properties of dissolution. Many benefits such as improving product quality, increasing energy efficiency and reducing times can be obtained by microwaves. This paper summarized characteristics of the microwave irradiation technique, new preparation techniques and formulation process in pharmaceutical industry by microwave irradiation technology. The microwave technology provides a new clue for heating and drying in the field of pharmaceutics.

The development of co-amorphous drug systems / 药学学报

Converting two poorly water-soluble crystalline drugs to co-amorphous drug systems by ball milling, quench-cooling, or cryo-milling method can improve stability of the drug, enhance dissolution rates, and reduce adverse reactions of the single drug. Co-amorphous system has been used to solve problems of co-administration of medicines. Formation and intermolecular interactions of co-amorphous drug systems may be verified by differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Raman spectroscopy (RS) and Fourier transform infrared spectroscopy (FT-IR). Stability of co-amorphous drug systems is influenced by their glass transition temperature (Tg) and intermolecular interactions. The theoretical Tg values and the interaction parameter x are calculated by Gordon-Taylor equation and the Flory-Huggins equation, respectively. Thus, co-amorphous drug systems are analyzed theoretically at molecular level. Co-amorphous drug systems provide a new sight for the co-administration of medicines.