Stability and aerosolization of pressurized metered dose inhalers containing thymopentin nanoparticles produced using a bottom-up process.

The objective of this study was to investigate the stability and aerosolization of pressurized metered dose inhalers (pMDIs) containing thymopentin nanoparticles. Thymopentin nanoparticles, fabricated by a bottom-up process, were suspended in hydrofluoroalkane (HFA) 134a together with cineole and/or n-heptane to produce pMDI formulations. The stability study of the pMDIs obtained was carried out at ambient temperature for 6 months. The amount of thymopentin and the aerosolization properties of pMDIs were determined using high-performance liquid chromatography (HPLC) and a twin-stage impinger (TSI), respectively. Based on the results, thymopentin nanoparticles were readily suspended in HFA 134a with the aid of cineole and/or n-heptane to form physically stable pMDI formulations, and more than 98% of the labeled amount of thymopentin and over 50% of the fine particle fraction (FPF) of the pMDIs were achieved. During storage, it was found that for all pMDIs more than 97% of the labeled amount of thymopentin and FPF greater than 47% were achieved. Moreover, the size of thymopentin nanoparticles in propellant containing cineole and n-heptane showed little change. It is, therefore, concluded that the pMDIs comprising thymopentin nanoparticles developed in this study were stable and suitable for inhalation therapy for systemic action.

Inhalable microparticles as carriers for pulmonary delivery of thymopentin-loaded solid lipid nanoparticles.

PURPOSE: Microparticles containing solid lipid nanoparticles (SLNs) are receiving increased attention as carriers for the lung delivery of the SLNs. Thus, we aim to prepare the hybrid microparticles and thoroughly evaluate their feasibility for the pulmonary drug delivery. METHODS: The microparticles were prepared by co-spray-drying the thymopentin (TP5)-loaded SLNs with bulking agents. Thereafter, we systematically estimated the potential of the microparticles as the carriers for the pulmonary delivery of the SLNs, including the investigations of their characteristics, aerodynamic properties, pharmacokinetics and pharmacodynamics. RESULTS: The spherical and hollow microparticles presented a size of 4.1 +/- 0.1 microm and a low tap density of 0.175 +/- 0.02 g/cm(3). In addition, the microparticles showed a high aerosolization efficiency (emitted dose of 98.0% +/- 1.23% and respirable fraction of 51.07% +/- 1.21%). Furthermore, the SLNs could be easily recovered from the microparticles without essential changes on their characteristics and the drug release behavior. The pharmacokinetic and pharmacodynamic studies suggested that, compared to i.v. TP5 solution, the bioavailability and therapeutic efficacy of TP5 were remarkably strengthened after the pulmonary administration of the microparticles. CONCLUSIONS: Taken together, we believe the microparticles were suitable for inhalation and possessed an ample potential for the pulmonary delivery of the SLNs.

[Preparation of sustained release multivesicular liposome for thymopentin and preliminary study on its pharmacokinetics in rats].

To optimize the formulation and preparation method of multivesicular liposome of thymopentin and to investigate its pharmacokinetics in rats, the multivesicular liposome of thymopentin was prepared by double emulsification method and the formulation was optimized by orthogonal design. The release characteristics of thymopentin from multivesicular liposome in PBS (pH 7.4) and in plasma were investigated. The multivesicular liposome of thymopentin labeled with fluorescein isothiocyanate was prepared by double emulsification method. Its pharmacokinetics was evaluated following intramuscular injection in rats. The optimal formulation of multivesicular liposome of thymopentin were formulated with 7.5% glucose in aqueous phase and 2.25 mol x L(-1) triolein, 2.68 mol x L(-1) DPPG and 16.96 mol x L(-1) DOPC in organic phase. The entrapment efficiency of the multivesicular liposome of thymopentin was above 85% and the mean particle size was about 22 microm. The in vitro release of thymopentin from multivesicular liposome in PBS (pH 7.4) and in plasma was found to be in a sustained manner. The release curves were fitted to Higuchi equation. The pharmacokinetics following intramuscular injection of the multivesicular liposome of thymopentin labeled with fluorescein isothiocyanate in rats showed that the peak concentration of thymopentin was lower and elimination of it was slower significantly than that of thymopentin labeled with fluorescein isothiocyanate solution in the same dose. The plasma concentration of thymopentin maintained above quantitative limitation at 120 h after administration of multivesicular liposome of thymopentin. The optimized formulation and preparation technology of multivesicular liposome of thymopentin with higher entrapment efficiency are feasible with good reproducibility. Multivesicular liposome of thymopentin showed significant sustained-release property following intramuscular injection in rats.

[Study on the efficacy and safety of high dose thymopentin combined with trans-artery chemoembolization for primary liver cancer].

OBJECTIVE: To evaluate the efficacy and safety of high doses of thymopentin (10 mg/d) combined with transartery chemoembolization for primary liver cancer. METHODS: Fifty primary liver cancer patients were randomly divided into two groups: therapeutic and control group, and all were treated with transfemoral artery chemoembolization (TACE) with oxaliplatin 150 mg, pharmorubicin 50 mg, 5-Fu 750 mg, CF 300 mg and lipiodol 20 ml. Therapeutic group (25) were added 10 mg thymopentin daily after TACE: i.v. on dl - d5, and im on D6 - D21. RESULTS: There was a significant difference in adverse effect and toxicity such as naupathia,fever, swirl, asthenia observed between two groups (P < 0.05). No difference in either pre- or post-chemotherapy peripheral blood examination and biochemical assay was found between two groups (P > 0.05). In control group, CD4+ cell was 37.92% +/- 8.71% in pre-treatment, which decreased to 29.16% +/- 8.21% in post-treatment with a significant difference (P < 0.01), whereas there was no evident difference in CD4+ cell between pre-treatment and post-treatment in the treatment group. CONCLUSION: Transartery chemoembolization combined with high dose of thymopentin in the treatment for primary liver cancer is effective and safe, and can significantly improve the immune function and the chemotherapy tolerance.

Chemo-immunotherapy in advanced head and neck cancer.

BACKGROUND: Patients with advanced squamous cell carcinoma of the head and neck (SCC) have a depressed immune system whose function is worsened by chemotherapy. In a pilot phase II study, in order to improve the immune function during chemotherapy, we combined to cisplatin (CDDP) and 5-fluorouracil (5-FU) two biological response modifiers, retinyl palmitate (R) and Thymopentin (TP-5) for the treatment of SCC. PATIENTS AND METHODS: Fifty patients with recurrent or metastatic SCC of the head and neck were treated with Cisplatin 24 mg/m2 from day 1 to 5 and 5-FU 1,000 mg/m2 by a 120 hour continuous infusion. Retinyl palmitate was administered orally 50,000 i.u. b.i.d and Thymopentin 50 mg subcutaneously 3 times a week. RESULTS: Chemotherapy treatment was well tolerated with G3 hematological toxicity in 30% of patients and G2 gastrointestinal toxicity in 20% of patients. 16 patients (32%) had a complete response (CR), 13 patients had partial response (PR) (26%), (response rate 58%, 95% c.i. 43%-72%); stable disease (SD) was observed in 7 patients (14%), while 14 patients progressed (PD) (28%). Median time to progression was 12 months (range 2.8-94.5). Median overall survival was 13.5 months (range 2-104). CONCLUSIONS: The association of CDDP and 5-FU with Retinyl Palmitate and TP5 has a major activity in the treatment of advanced head and neck cancer and a relatively well tolerated toxicity.