scholarly journals Erratum: Investigation of drug release and 1 H-NMR analysis of the in situ forming systems based on poly(lactide-co-glycolide)

2009 ◽  
Vol 20 (5) ◽  
pp. 507-507
Author(s):  
Z. Mohamadnia ◽  
E. Ahmadi ◽  
M. Rafienia ◽  
H. Mirzadeh ◽  
H. Mobedi
2007 ◽  
Vol 25 (6) ◽  
pp. 1347-1354 ◽  
Author(s):  
Heiko Kranz ◽  
Erol Yilmaz ◽  
Gayle A. Brazeau ◽  
Roland Bodmeier

2019 ◽  
Vol 53 ◽  
pp. 101180 ◽  
Author(s):  
C. Bode ◽  
H. Kranz ◽  
A. Kruszka ◽  
F. Siepmann ◽  
J. Siepmann
Keyword(s):  

2013 ◽  
Vol 545 ◽  
pp. 63-68 ◽  
Author(s):  
Jongjan Mahadlek ◽  
Juree Charoenteeraboon ◽  
Thawatchai Phaechamud

Periodontitis is an inflammatory disease of the supporting structures of the tooth caused by bacterial infection which can result in tooth loss. The local intra-pocket drug delivery system was interesting and highly effective for periodontitis treatment. In situ forming gel system is the polymeric solution which could transform into gel for localizing and sustaining the drug release at desired site. This system has been recommended as one of suitable delivery system for this purpose. Benzoyl peroxide (BPO) in situ forming gels were developed using Eudragit RS as polymer dispersed in N-methyl-pyrrolidone (NMP). Peppermint oil and polyethylene glycol 1500 were also incorporated as the excipients. The prepared systems were evaluated for rheology, syringeability (using texture analyzers), in situ gel formation (after injection into PBS pH 6.8), antimicrobial activity (against Streptococcus mutans with agar diffusion) and drug release (with dialysis method in PBS pH 6.8 at 50 rpm, 37 °C). The viscosity and syringeability of the prepared systems was increased as the amount of BPO, peppermint oil or PEG 1500 was increased. All prepared gels showed the Newtonian flow which the viscosity was decreased as the temperature was increased. All prepared gels comprising peppermint oil and PEG 1500 could form in situ gel in used medium which the pH was close to the environment pH of periodontal pocket. The inhibition zone against Streptococcus mutans of the prepared system was significantly decreased when the peppermint oil and PEG 1500 was incorporated owing to the higher viscous environment and thereafter retardation of drug diffusion was evident. This effect could prolong the drug release. From drug release test, all prepared gels could sustain the BPO release for at least 96 hrs. Release kinetic obtained from curve fitting with various release equations using least square fit technique indicated that the release patterns were as Higuchi’s model therefore the release of BPO was performed with diffusion control. This developed BPO in situ forming gel presented its ability as the controlled drug delivery system for localized antimicrobial activity at periodontal pocket.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 520 ◽  
Author(s):  
Xiaowei Zhang ◽  
Liqun Yang ◽  
Chong Zhang ◽  
Danhua Liu ◽  
Shu Meng ◽  
...  

To explore the mechanism of drug release and depot formation of in situ forming implants (ISFIs), osthole-loaded ISFIs were prepared by dissolving polylactide, poly(lactide-co-glycolide), polycaprolactone, or poly(trimethylene carbonate) in different organic solvents, including N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), and triacetin (TA). Drug release, polymer degradation, solvent removal rate and depot microstructure were examined. The burst release effect could be reduced by using solvents exhibit slow forming phase inversion and less permeable polymers. Both the drug burst release and polymer depot microstructure were closely related to the removal rate of organic solvent. Polymers with higher permeability often displayed faster drug and solvent diffusion rates. Due to high polymer-solvent affinity, some of the organic solvent remained in the depot even after the implant was completely formed. The residual of organic solvent could be predicted by solubility parameters. The ISFI showed a lower initial release in vivo than that in vitro. In summary, the effects of different polymers and solvents on drug release and depot formation in ISFI systems were extensively investigated and discussed in this article. The two main factors, polymer permeability and solvent removal rate, were involved in different stages of drug release and depot formation in ISFI systems.


2015 ◽  
Vol 29 (10) ◽  
pp. 1343-1350 ◽  
Author(s):  
Maryam Dehghan-Niri ◽  
Moslem Tavakol ◽  
Ebrahim Vasheghani-Farahani ◽  
Fariba Ganji

2021 ◽  
Vol 18 ◽  
Author(s):  
Saeed Bazraee ◽  
Hamid Mobedi ◽  
Arezuo Mashak ◽  
Ahmad Jamshidi

Introduction: Typically, in situ forming implants utilize Poly (lactide-co-glycolide) (PLGA) as a carrier and N-methyl-2-pyrrolidone (NMP) as a solvent. However, it is essential to develop different carriers to release various drugs in a controlled and sustained manner with economic and safety considerations. Objective: The present study aims to evaluate the in-vitro release of Bupivacaine HCl from in situ forming systems as post-operative local anesthesia. Methods: We used Sucrose acetate isobutyrate (SAIB), PLGA 50:50, and a mixture of them as carriers to compare the release behavior. Besides, the effect of PLGA molecular weight (RG 502H, RG 503H, and RG 504H), solvent type, and solvent concentration on the drug release profile was evaluated. The formulations were characterized by investigating their in-vitro drug release, rheological properties, solubility, and DSC, in addition to their morphological properties. Furthermore, the Korsmeyer-Peppas and Weibull models were applied to the experimental data. The results revealed that a mixture of SAIB and PLGA compared to using them solely can extend the Bupivacaine HCl release from 3 days to two weeks. Results: The DSC results demonstrated the compatibility of the mixture by showing a single Tg. The formulation with NMP had a higher burst release and final release in comparison with other solvents by 30% and 96%, respectively. Increasing the solvent concentration from 12% to 32% raised the drug release significantly, which confirmed the larger porosity in the morphology results. From the Korsmeyer-Peppas model, the mechanism of drug release is predicted to be non-Fickian diffusion.


RSC Advances ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 5349-5361 ◽  
Author(s):  
LiNa Wang ◽  
Xiao Lin ◽  
YanLong Hong ◽  
Lan Shen ◽  
Yi Feng

To obtain a sustained in vivo release of Radix Ophiopogonis polysaccharide, hydrophobic solvent-induced in situ forming systems were investigated, including the factors affecting drug release and anti-myocardial ischemic activity of a formulation.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1231
Author(s):  
Sandy Van Hemelryck ◽  
Rani Wens ◽  
Hannelore van Poppel ◽  
Milou Luijks ◽  
Koosha Shahidi ◽  
...  

This study evaluated in vitro and in vivo drug release of bedaquiline from in situ forming gels (ISGs) containing 200 mg eq./g bedaquiline fumarate salt prepared with four different grades of poly(d,l-lactide) (PDLLA) or poly(d,l-lactide-co-glycolide) (PLGA) with a lactide/glycolide ratio of 50/50 or 75/25 and acid (A) or ester (E) end-capping in N-methyl-2-pyrrolidone at a polymer/solvent ratio of 20/80% (w/w). Mean in vitro drug release in 0.05 M phosphate buffer pH 7.4 with 1% (w/v) sodium lauryl sulphate was 37.3, 47.1, 53.3, and 62.3% within 28 days for ISGs containing PLGA5050A, PDLLA, PLGA7525A, and PLGA7525E, respectively. The data suggested that drug release was primarily controlled by precipitated drug redissolving, rather than polymer erosion. In vivo pharmacokinetic profiles after subcutaneous injections in rats were comparable for all ISGs (mean half-lives (t1/2) ranged from 1411 to 1695 h) and indicated a sustained drug release when compared to a solution of bedaquiline fumarate salt in polyethylene glycol 400/water 50/50% (v/v) (mean t1/2 of 895 h). In conclusion, PLGA or PDLLA-based ISGs have shown potential for parenteral sustained delivery of bedaquiline, suggesting further preclinical and clinical studies. From a formulation point of view, this case example highlights the importance of the interplay between drug solubility in biological media and dissolution of drug precipitates, which, in addition to the incorporation of diffusion controlling polymers, governs the release of the active drug.


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