scholarly journals Development of injectable long‐acting controlled release intravitreal depot of BAY224 using biodegradable silica microparticle‐silica hydrogel composite

2021 ◽  
Vol 99 (S265) ◽  
Author(s):  
Frederic Dargelas ◽  
Aripekka Forsback ◽  
Aarne Mattila ◽  
Lasse Leino ◽  
Panu Noppari ◽  
...  
2020 ◽  
Vol 22 (1) ◽  
pp. 340
Author(s):  
Ilya Nifant’ev ◽  
Andrei Siniavin ◽  
Eduard Karamov ◽  
Maxim Kosarev ◽  
Sergey Kovalchuk ◽  
...  

Despite the world’s combined efforts, human immunodeficiency virus (HIV), the causative agent of AIDS, remains one of the world’s most serious public health challenges. High genetic variability of HIV complicates the development of anti-HIV vaccine, and there is an actual clinical need for increasing the efficiency of anti-HIV drugs in terms of targeted delivery and controlled release. Tenofovir (TFV), a nucleotide-analog reverse transcriptase inhibitor, has gained wide acceptance as a drug for pre-exposure prophylaxis or treatment of HIV infection. In our study, we explored the potential of tenofovir disoproxil (TFD) adducts with block copolymers of poly(ethylene glycol) monomethyl ether and poly(ethylene phosphoric acid) (mPEG-b-PEPA) as candidates for developing a long-acting/controlled-release formulation of TFV. Two types of mPEG-b-PEPA with numbers of ethylene phosphoric acid (EPA) fragments of 13 and 49 were synthesized by catalytic ring-opening polymerization, and used for preparing four types of adducts with TFD. Antiviral activity of [mPEG-b-PEPA]TFD or tenofovir disoproxil fumarate (TDF) was evaluated using the model of experimental HIV infection in vitro (MT-4/HIV-1IIIB). Judging by the values of the selectivity index (SI), TFD exhibited an up to 14-fold higher anti-HIV activity in the form of mPEG-b-PEPA adducts, thus demonstrating significant promise for further development of long-acting/controlled-release injectable TFV formulations.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 816
Author(s):  
Yuxuan Ge ◽  
Zhenhua Hu ◽  
Jili Chen ◽  
Yujie Qin ◽  
Fei Wu ◽  
...  

GLP-1 receptor agonists are a class of diabetes medicines offering self-regulating glycemic efficacy and may best be administrated in long-acting forms. Among GLP-1 receptor agonists, exenatide is the one requiring the least dose so that controlled-release poly(d, l-lactic-co-glycolic acid) (PLGA) microspheres may best achieve this purpose. Based on this consideration, the present study extended the injection interval of exenatide microspheres from one week of the current dosage form to four weeks by simply blending Mg(OH)2 powder within the matrix of PLGA microspheres. Mg(OH)2 served as the diffusion channel creator in the earlier stage of the controlled-release period and the decelerator of the self-catalyzed degradation of PLGA (by the formed lactic and glycolic acids) in the later stage due to its pH-responsive solubility. As a result, exenatide gradually diffused from the microspheres through Mg(OH)2-created diffusion channels before degradation of the PLGA matrix, followed by a mild release due to Mg(OH)2-buffered degradation of the polymer skeleton. In addition, an extruding–settling process comprising squeezing the PLGA solution through a porous glass membrane and sedimentation-aided solidification of the PLGA droplets was used to prepare the microspheres to ensure narrow size distribution and 95% encapsulation efficiency in an aqueous continuous phase. A pharmacokinetic study using rhesus monkey model confirmed the above formulation design by showing a steady blood concentration profile of exenatide with reduced CMAX and dosage form index. Mg·(OH)2


Author(s):  
Kaja Križman ◽  
Saša Novak ◽  
Julijana Kristl ◽  
Gregor Majdič ◽  
Nataša Drnovšek

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1335
Author(s):  
Lingxiao Xie ◽  
Weizhou Yue ◽  
Khaled Ibrahim ◽  
Jie Shen

Uveal melanoma (UM) is the most common primary intraocular tumor in adults with high mortality. In order to improve prognosis and survival of UM patients, it is critical to inhibit tumor progression and metastasis as early as possible after the initial presentation/diagnosis of the disease. Sustained local delivery of antitumor therapeutics in the posterior region can potentially achieve long-term UM inhibition, improve target therapeutic delivery to the posterior segments, as well as reduce injection frequency and hence improved patient compliance. To address the highly unmet medical need in UM therapy, a bioinspired in situ gelling hydrogel system composed of naturally occurring biopolymers collagen and hyaluronic acid was developed in the present research. Curcumin with anti-cancer progression, anti-metastasis effects, and good ocular safety was chosen as the model therapeutic. The developed in situ gelling delivery system gelled at 37 °C within two minutes and demonstrated excellent biocompatibility and slow degradation. The curcumin-loaded nanoparticle/hydrogel composite was able to sustain release payload for up to four weeks. The optimized nanoparticle/hydrogel composite showed effective inhibition of human UM cell proliferation. This novel nanoparticle/in situ hydrogel composite demonstrated a great potential for the treatment of the rare and devastating intraocular cancer.


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