1
|
Yang F, Stahnke R, Lawal K, Mahnen C, Duffy P, Xu S, Durig T. Development of poly (lactic-co-glycolic acid) (PLGA) based implants using hot melt extrusion (HME) for sustained release of drugs: The impacts of PLGA's material characteristics. Int J Pharm 2024; 663:124556. [PMID: 39122196 DOI: 10.1016/j.ijpharm.2024.124556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 07/26/2024] [Accepted: 08/02/2024] [Indexed: 08/12/2024]
Abstract
Hot melt extrusion (HME) processed Poly (lactic-co-glycolic acid) (PLGA) implant is one of the commercialized drug delivery products, which has solid, well-designed shape and rigid structures that afford efficient locoregional drug delivery on the spot of interest for months. In general, there are a variety of material, processing, and physiological factors that impact the degradation rates of PLGA-based implants and concurrent drug release kinetics. The objective of this study was to investigate the impacts of PLGA's material characteristics on PLGA degradation and subsequent drug release behavior from the implants. Three model drugs (Dexamethasone, Carbamazepine, and Metformin hydrochloride) with different water solubility and property were formulated with different grades of PLGAs possessing distinct co-polymer ratios, molecular weights, end groups, and levels of residual monomer (high/ViatelTM and low/ ViatelTM Ultrapure). Physicochemical characterizations revealed that the plasticity of PLGA was inversely proportional to its molecular weight; moreover, the residual monomer could impose a plasticizing effect on PLGA, which increased its thermal plasticity and enhanced its thermal processability. Although the morphology and microstructure of the implants were affected by many factors, such as processing parameters, polymer and drug particle size and distribution, polymer properties and polymer-drug interactions, implants prepared with ViatelTM PLGA showed a smoother surface and a stronger PLGA-drug intimacy than the implants with ViatelTM Ultrapure PLGA, due to the higher plasticity of the ViatelTM PLGA. Subsequently, the implants with ViatelTM PLGA exhibited less burst release than implants with ViatelTM Ultrapure PLGA, however, their onset and progress of the lag and substantial release phases were shorter and faster than the ViatelTM Ultrapure PLGA-based implants, owing to the residual monomer accelerated the water diffusion and autocatalyzed PLGA hydrolysis. Even though the drug release profiles were also influenced by other factors, such as composition, drug properties and polymer-drug interaction, all three cases revealed that the residual monomer accelerated the swelling and degradation of PLGA and impaired the implant's integrity, which could negatively affect the subsequent drug release behavior and performance of the implants. These results provided insights to formulators on rational PLGA implant design and polymer selection.
Collapse
Affiliation(s)
| | - Ryan Stahnke
- Ashland Specialty Ingredients, Wilmington, DE, USA
| | - Kamaru Lawal
- Ashland Specialty Ingredients, Wilmington, DE, USA
| | - Cory Mahnen
- Ashland Specialty Ingredients, Wilmington, DE, USA
| | | | - Shuyu Xu
- Ashland Specialty Ingredients, Wilmington, DE, USA
| | - Thomas Durig
- Ashland Specialty Ingredients, Wilmington, DE, USA
| |
Collapse
|
2
|
Block M, Sieger P, Truenkle C, Saal C, Simon R, Truebenbach I. Miniaturized screening and performance prediction of tailored subcutaneous extended-release formulations for preclinical in vivo studies. Eur J Pharm Sci 2024; 196:106733. [PMID: 38408709 DOI: 10.1016/j.ejps.2024.106733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 02/28/2024]
Abstract
Microencapsulation of active pharmaceutical ingredients (APIs) for preparation of long acting injectable (LAI) formulations is an auspicious technique to enable preclinical characterization of a broad variety of APIs, ideally independent of their physicochemical and pharmacokinetic (PK) characteristics. During early API discovery, tunable LAI formulations may enable pharmacological proof-of-concept for the given variety of candidates by tailoring the level of plasma exposure over the duration of various timespans. Although numerous reports on small scale preparation methods for LAIs utilizing copolymers of lactic and glycolic acid (PLGA) and polymers of lactic acid (PLA) highlight their potential, application in formulation screening and use in preclinical in vivo studies is yet very limited. Transfer from downscale formulation preparation to in vivo experiments is hampered in early preclinical API screening by the large number of API candidates with simultaneously very limited available amount in the lower sub-gram scale, lack of formulation stability and deficient tunability of sustained release. We hereby present a novel comprehensive platform tool for tailored extended-release formulations, aiming to support a variety of preclinical in vivo experiments with ranging required plasma exposure levels and timespans. A novel small-scale spray drying process was successfully implemented by using an air brush based instrument for preparation of PLGA and PLA based formulations. Using Design of Experiments (DoE), required API amount of 250 mg was demonstrated to suffice for identification of dominant polymer characteristics with largest impact on sustained release capability for an individual API. BI-3231, a hydrophilic and weakly acidic small compound with good water solubility and permeability, but low metabolic stability, was used as an exemplary model for one of the many candidates during API discovery. Furthermore, an in vitro to in vivo correlation (IVIVC) of API release rate was established in mice, which enabled the prediction of in vivo plasma concentration plateaus after single subcutaneous injection, using only in vitro dissolution profiles of screened formulations. By tailoring LAI formulations and their doses for acute and sub-chronic preclinical experiments, we exemplary demonstrate the practical use for BI-3231. Pharmacological proof-of-concept could be enabled whilst circumventing the need of multiple administration as result of extensive hepatic metabolism and simultaneously superseding numerous in vivo experiments for formulation tailoring.
Collapse
Affiliation(s)
- Marco Block
- Department of Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riß 88397, Germany
| | - Peter Sieger
- Department of Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riß 88397, Germany
| | - Cornelius Truenkle
- Department of Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riß 88397, Germany
| | - Christoph Saal
- Department of Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riß 88397, Germany
| | - Roman Simon
- Department of Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riß 88397, Germany
| | - Ines Truebenbach
- Department of Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riß 88397, Germany.
| |
Collapse
|
3
|
Bakhrushina EO, Sakharova PS, Konogorova PD, Pyzhov VS, Kosenkova SI, Bardakov AI, Zubareva IM, Krasnyuk II, Krasnyuk II. Burst Release from In Situ Forming PLGA-Based Implants: 12 Effectors and Ways of Correction. Pharmaceutics 2024; 16:115. [PMID: 38258125 PMCID: PMC10819773 DOI: 10.3390/pharmaceutics16010115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 01/04/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
In modern pharmaceutical technology, modified-release dosage forms, such as in situ formed implants, are gaining rapidly in popularity. These dosage forms are created based on a configurable matrix consisting of phase-sensitive polymers capable of biodegradation, a hydrophilic solvent, and the active substance suspended or dissolved in it. The most used phase-sensitive implants are based on a biocompatible and biodegradable polymer, poly(DL-lactide-co-glycolide) (PLGA). OBJECTIVE This systematic review examines the reasons for the phenomenon of active ingredient "burst" release, which is a major drawback of PLGA-based in situ formed implants, and the likely ways to correct this phenomenon to improve the quality of in situ formed implants with a poly(DL-lactide-co-glycolide) matrix. DATA SOURCES Actual and relevant publications in PubMed and Google Scholar databases were studied. STUDY SELECTION The concept of the review was based on the theory developed during literature analysis of 12 effectors on burst release from in situ forming implants based on PLGA. Only those studies that sufficiently fully disclosed one or another component of the theory were included. RESULTS The analysis resulted in development of a systematic approach called the "12 Factor System", which considers various constant and variable, endogenous and exogenous factors that can influence the nature of 'burst release' of active ingredients from PLGA polymer-based in situ formed implants. These factors include matrix porosity, polymer swelling, LA:GA ratio, PLGA end groups, polymer molecular weight, active ingredient structure, polymer concentration, polymer loading with active ingredients, polymer combination, use of co-solvents, addition of excipients, and change of dissolution conditions. This review also considered different types of kinetics of active ingredient release from in situ formed implants and the possibility of using the "burst release" phenomenon to modify the active ingredient release profile at the site of application of this dosage form.
Collapse
Affiliation(s)
| | | | | | - Victor S. Pyzhov
- Department of Pharmaceutical Technology, A.P. Nelyubin Institute of Pharmacy, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow 119048, Russia; (E.O.B.); (P.S.S.); (P.D.K.); (S.I.K.); (A.I.B.); (I.M.Z.); (I.I.K.); (I.I.K.J.)
| | | | | | | | | | | |
Collapse
|
4
|
Duvnjak M, Villois A, Ramazani F. Biodegradable Long-Acting Injectables: Platform Technology and Industrial Challenges. Handb Exp Pharmacol 2024; 284:133-150. [PMID: 37059910 DOI: 10.1007/164_2023_651] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Long-acting injectables have been used to benefit patients with chronic diseases. So far, several biodegradable long-acting platform technologies including drug-loaded polymeric microparticles, implants (preformed and in situ forming), oil-based solutions, and aqueous suspension have been established. In this chapter, we summarize all the marketed technology platforms and discuss their challenges regarding development including but not limited to controlling drug release, particle size, stability, sterilization, scale-up manufacturing, etc. Finally, we discuss important criteria to consider for the successful development of long-acting injectables.
Collapse
Affiliation(s)
- Marieta Duvnjak
- Technical Research and Development, Novartis Pharma AG, Basel, Switzerland
| | - Alessia Villois
- Technical Research and Development, Novartis Pharma AG, Basel, Switzerland
| | - Farshad Ramazani
- Technical Research and Development, Novartis Pharma AG, Basel, Switzerland.
| |
Collapse
|
5
|
Pandya AK, Vora LK, Umeyor C, Surve D, Patel A, Biswas S, Patel K, Patravale VB. Polymeric in situ forming depots for long-acting drug delivery systems. Adv Drug Deliv Rev 2023; 200:115003. [PMID: 37422267 DOI: 10.1016/j.addr.2023.115003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/27/2023] [Accepted: 07/04/2023] [Indexed: 07/10/2023]
Abstract
Polymeric in situ forming depots have emerged as highly promising drug delivery systems for long-acting applications. Their effectiveness is attributed to essential characteristics such as biocompatibility, biodegradability, and the ability to form a stable gel or solid upon injection. Moreover, they provide added versatility by complementing existing polymeric drug delivery systems like micro- and nanoparticles. The formulation's low viscosity facilitates manufacturing unit operations and enhances delivery efficiency, as it can be easily administered via hypodermic needles. The release mechanism of drugs from these systems can be predetermined using various functional polymers. To enable unique depot design, numerous strategies involving physiological and chemical stimuli have been explored. Important assessment criteria for in situ forming depots include biocompatibility, gel strength and syringeability, texture, biodegradation, release profile, and sterility. This review focuses on the fabrication approaches, key evaluation parameters, and pharmaceutical applications of in situ forming depots, considering perspectives from academia and industry. Additionally, insights about the future prospects of this technology are discussed.
Collapse
Affiliation(s)
- Anjali K Pandya
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai 400 019, India; School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, BT9 7BL, UK
| | - Lalitkumar K Vora
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, BT9 7BL, UK
| | - Chukwuebuka Umeyor
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai 400 019, India; Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka 422001, Anambra State, Nigeria
| | - Dhanashree Surve
- Department of Chemical Engineering, University of Massachusetts, Amherst, MA, USA
| | - Akanksha Patel
- College of Pharmacy and Health Sciences, St. John's University, Queens, NY, USA
| | - Swati Biswas
- Department of Pharmacy, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Jawahar Nagar, Medchal, Hyderabad, Telangana 500078, India
| | - Ketankumar Patel
- College of Pharmacy and Health Sciences, St. John's University, Queens, NY, USA
| | - Vandana B Patravale
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai 400 019, India.
| |
Collapse
|
6
|
Saraf I, Kushwah V, Alva C, Koutsamanis I, Rattenberger J, Schroettner H, Mayrhofer C, Modhave D, Braun M, Werner B, Zangger K, Paudel A. Influence of PLGA End Groups on the Release Profile of Dexamethasone from Ocular Implants. Mol Pharm 2023; 20:1307-1322. [PMID: 36680524 DOI: 10.1021/acs.molpharmaceut.2c00945] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The present study deals with the development of dexamethasone (DM)-loaded implants using ester end-capped Resomer RG 502 poly(lactic acid-co-glycolic acid) (PLGA) (502), acid end-capped Resomer RG 502H PLGA (502H), and a 502H:502 mixture (3:1) via hot melt extrusion (HME). The prepared intravitreal implants (20 and 40% DM loaded in each PLGA) were thoroughly investigated to determine the effect of different end-capped PLGA and drug loading on the long-term release profile of DM. The implants were characterized for solid-state active pharmaceutical ingredient (APIs) using DSC and SWAXS, water uptake during stability study, the crystal size of API in the implant matrix using hot-stage polarized light microscopy, and in vitro release profile. The kinetics of PLGA release was thoroughly investigated using quantitative 1H NMR spectroscopy. The polymorph of DM crystal was found to remain unchanged after the extrusion and stability study. However, around 3 times reduction in API particle size was observed after the HME process. The morphology and content uniformity of the RT-stored samples were found to be comparable to the initial implant samples. Interestingly, the samples (mainly 502H) stored at 40 °C and 75% RH for 30 d demonstrated marked deformation and a change in content uniformity. The rate of DM release was higher in the case of 502H samples with a higher drug loading (40% w/w). Furthermore, a simple digital in vitro DM release profile derived for the formulation containing a 3:1 ratio of 502H and 502 was comparable with the experimental release profile of the respective polymer mixture formulation. The temporal development of pores and/or voids in the course of drug dissolution, evaluated using μCT, was found to be a precursor for the PLGA release. Overall, the release profile of DM was found to be dependent on the PLGA type (independent of subtle changes in the formulation mass and diameter). However, the extent of release was found to be dependent on DM loading. Thus, the present investigation led to a thorough understanding of the physicochemical properties of different end-capped PLGAs and the underlying formulation microstructure on the release profile of a crystalline water-insoluble drug, DM, from the PLGA-based implant.
Collapse
Affiliation(s)
- Isha Saraf
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | - Varun Kushwah
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | - Carolina Alva
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | - Ioannis Koutsamanis
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | | | - Hartmuth Schroettner
- Graz Centre for Electron Microscopy (ZFE), Steyrergasse 17, Graz8010, Austria.,Institute of Electron Microscopy and Nanoanalysis (FELMI), NAWI Graz, Graz University of Technology, Steyrergasse 17, Graz8010, Austria
| | - Claudia Mayrhofer
- Graz Centre for Electron Microscopy (ZFE), Steyrergasse 17, Graz8010, Austria
| | - Dattatray Modhave
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | - Michael Braun
- Pharmaceutical Development, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach88397, Germany
| | - Bernd Werner
- Institute of Chemistry, University of Graz, Heinrichstr. 28, Graz8010, Austria
| | - Klaus Zangger
- Institute of Chemistry, University of Graz, Heinrichstr. 28, Graz8010, Austria
| | - Amrit Paudel
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria.,Institute for Process and Particle Engineering, Graz University of Technology, Inffeldgasse 13/3, Graz8010, Austria
| |
Collapse
|
7
|
Bassand C, Benabed L, Freitag J, Verin J, Siepmann F, Siepmann J. How bulk fluid renewal can affect in vitro drug release from PLGA implants: Importance of the experimental set-up. Int J Pharm X 2022; 4:100131. [PMID: 36189458 PMCID: PMC9519472 DOI: 10.1016/j.ijpx.2022.100131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/30/2022] [Accepted: 09/16/2022] [Indexed: 11/08/2022] Open
Abstract
The aim of this study was to better understand the potential impact of partial vs. complete renewal of the bulk fluid during drug release measurements from poly (lactic-co-glycolic acid) (PLGA)-based implants. A “standard experimental set-up”, in which the implants were directly exposed to well agitated phosphate buffer pH 7.4 was used, as well as set-ups, in which the implants were embedded within agarose hydrogels (mimicking living tissue). The gels were exposed to well agitated phosphate buffer pH 7.4. Ibuprofen-loaded implants were prepared by hot melt extrusion. The systems were thoroughly characterized before and during drug release by optical and scanning electron microscopy, gravimetric analysis, pH and solubility measurements as well as gel permeation chromatography. The bulk fluid was either completely or partially replaced by fresh medium at each sampling time point. In all cases, sink conditions were provided in the agitated bulk fluids throughout the experiments. Interestingly, the agarose set-ups did not show any noteworthy impact of the bulk fluid sampling volume on the observed drug release patterns, whereas complete fluid renewal in the “standard set-up” led to accelerated drug release. This could be explained by the considerable fragility of the implants once substantial polymer swelling set on, transforming them into PLGA gels: Complete fluid renewal caused partial disintegration and damage of the highly swollen systems, decreasing the lengths of the diffusion pathways for the drug. The mechanical stress is very much reduced at low sampling volumes, or if the implants are embedded within agarose gels. Thus, great care must be taken when defining the conditions for in vitro drug release measurements from PLGA-based implants: Once substantial system swelling sets on, the devices become highly fragile.
Collapse
|
8
|
Bock F, Bøtker JP, Larsen SW, Lu X, Østergaard J. Methodological Considerations in Development of UV Imaging for Characterization of Intra-Tumoral Injectables Using cAMP as a Model Substance. Int J Mol Sci 2022; 23:ijms23073599. [PMID: 35408971 PMCID: PMC8998202 DOI: 10.3390/ijms23073599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/17/2022] [Accepted: 03/23/2022] [Indexed: 12/19/2022] Open
Abstract
A UV imaging release-testing setup comprising an agarose gel as a model for tumorous tissue was developed. The setup was optimized with respect to agarose concentration (0.5% (w/v)), injection procedure, and temperature control. A repeatable injection protocol was established allowing injection into cavities with well-defined geometries. The effective resolution of the SDi2 UV imaging system is 30-80 µm. The linear range of the imaging system is less than that of typical spectrophotometers. Consequently, non-linear cAMP calibration curves were applied for quantification at 280 nm. The degree of deviation from Beer's law was affected by the background absorbance of the gel matrix. MATLAB scripts provided hitherto missing flexibility with respect to definition and utilization of quantification zones, contour lines facilitating visualization, and automated, continuous data analysis. Various release patterns were observed for an aqueous solution and in situ forming Pluronic F127 hydrogel and PLGA implants containing cAMP as a model for STING ligands. The UV imaging and MATLAB data analysis setup constituted a significant technical development in terms of visualizing behavior for injectable formulations intended for intra-tumoral delivery, and, thereby, a step toward establishment of a bio-predictive in vitro release-testing method.
Collapse
Affiliation(s)
- Frederik Bock
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark; (F.B.); (J.P.B.); (S.W.L.)
| | - Johan Peter Bøtker
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark; (F.B.); (J.P.B.); (S.W.L.)
| | - Susan Weng Larsen
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark; (F.B.); (J.P.B.); (S.W.L.)
| | - Xujin Lu
- Bristol Myers Squibb Company, Drug Product Development, 1 Squibb Drive, New Brunswick, NJ 08901, USA;
| | - Jesper Østergaard
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark; (F.B.); (J.P.B.); (S.W.L.)
- Correspondence: ; Tel.: +45-35336138
| |
Collapse
|
9
|
Ren T, Chen J, Qi P, Xiao P, Wang P. Goserelin/PLGA solid dispersion used to prepare long-acting microspheres with reduced initial release and reduced fluctuation of drug serum concentration in vivo. Int J Pharm 2022; 615:121474. [PMID: 35041918 DOI: 10.1016/j.ijpharm.2022.121474] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/02/2022] [Accepted: 01/11/2022] [Indexed: 12/19/2022]
Abstract
To prepare Goserelin (GOS) loaded long-acting microspheres with reduced initial release and prolonged drug release time of GOS, GOS/PLGA solid dispersion (by hot-melt extrusion, HME) was dissolved/dispersed in dichloromethane (DCM) to prepare microspheres by O/W method. From results of molecular dynamics simulation, PLGA and GOS molecules completely and uniformly dissolved and dispersed in DCM, respectively. In F5 microspheres (prepared by HME-O/W method), GOS existed as molecular or amorphous state, but not aggregation. Burst release of F5 microspheres (2.75%) was similar with ZoladexTM implant (0.39%) and less than F10 microspheres (prepared by S/O/W method, 25.92%). After lag phase, GOS released rapidly from F5 microspheres and the cumulative release on the 45th days was 95.14%. After injection of F5 microspheres, GOS serum concentration was relative steady at the range of 27.64-175.27 ng/mL for nearly 35 days. AUC(0-35 day) of F5 microspheres was almost 2 times that of F10 microspheres. Pharmacodynamics study also showed potential effect of F5 microspheres on inhibiting the secretion of testosterone in male rats. HME-O/W method is potential to establish long-acting PLGA microspheres (loading water-soluble drug) , exhibiting stable drug serum concentration in vivo, and without large concentration fluctuation or serious pain/side effects.
Collapse
Affiliation(s)
- Tianyang Ren
- Department of Pharmacy, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Jin Chen
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, PR of China
| | - Pan Qi
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, PR of China
| | - Peifu Xiao
- Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, PR of China
| | - Puxiu Wang
- Department of Pharmacy, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning, PR China.
| |
Collapse
|
10
|
Drug release from in situ forming implants and advances in release testing. Adv Drug Deliv Rev 2021; 178:113912. [PMID: 34363860 DOI: 10.1016/j.addr.2021.113912] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/29/2021] [Accepted: 07/29/2021] [Indexed: 12/29/2022]
Abstract
In situ forming implants, defined as liquid formulations that generate solid or semisolid depots following administration, have shown a range of advantages in drug delivery. This drug delivery strategy allows localized delivery, sustained drug release over periods of days to months, and is a less invasive option compared to traditional solid implants which typically require surgical implantation. Unfortunately, there are a number of quality control challenges in terms of drug release testing of these delivery systems which is likely to have contributed to the relatively few commercially available in situ forming implant products. This article reviews current marketed in situ forming implant products, FDA guidance on in vitro release testing, and formulation and environmental parameters influencing drug release from in situ forming implants. Formulation considerations for development of biological agents loaded in situ forming implants are also discussed. The advantages and limitations of typically used in vitro release testing methods are summarized. Difficulties in the development of in vitro-in vivo correlations (IVIVCs) for in situ forming implant are discussed. The knowledge presented will be helpful for the development of in situ forming implants, as well as for the development of appropriate in vitro testing methods and IVIVCs.
Collapse
|
11
|
Tamani F, Bassand C, Hamoudi M, Siepmann F, Siepmann J. Mechanistic explanation of the (up to) 3 release phases of PLGA microparticles: Monolithic dispersions studied at lower temperatures. Int J Pharm 2021; 596:120220. [DOI: 10.1016/j.ijpharm.2021.120220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/22/2020] [Accepted: 12/25/2020] [Indexed: 12/27/2022]
|
12
|
Controlled Drug Release by the Pore Structure in Polydimethylsiloxane Transdermal Patches. Polymers (Basel) 2020; 12:polym12071520. [PMID: 32650625 PMCID: PMC7407597 DOI: 10.3390/polym12071520] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/01/2020] [Accepted: 07/04/2020] [Indexed: 11/16/2022] Open
Abstract
The use of polydimethylsiloxanes (PDMS) as a drug carrier in transdermal adhesive patches is limited and there is insufficient data on the polymer structure and diffusivity, especially when additives modify the matrix. PDMS films with liquid additives (10% w/w): silicone oil (SO), polyoxyethylene glycol (PEG) or propylene glycol (PG) were prepared and indomethacin (IND; 5% w/w) was incorporated as a model active substance. The microstructure of the PDMS matrix and its permeability to water was investigated and correlated to the kinetics of the in-vitro IND release from the film. Three microscopic techniques were used to characterize in detail the microstructure of PDMS films: scanning electron microscopy, fluorescent microscopy and atomic force microscopy. PDMS films with hydrophilic PEG or PG showed different two-phase structures. A two-fold increase in steady-state flux of IND and increased water transport in the presence of PEG was attributed to the pore-like channels created by this polar solvent in the PDMS matrix. This effect was not observed in the films with PG, where only discontinuous droplet-like structures were visible. All additives significantly changed the tensile parameters of the films but the effects were not very pronounced.
Collapse
|
13
|
Tamani F, Bassand C, Hamoudi MC, Danede F, Willart JF, Siepmann F, Siepmann J. Mechanistic explanation of the (up to) 3 release phases of PLGA microparticles: Diprophylline dispersions. Int J Pharm 2019; 572:118819. [PMID: 31726196 DOI: 10.1016/j.ijpharm.2019.118819] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 01/29/2023]
Abstract
The aim of this study was to better understand the root causes for the (up to) 3 drug release phases observed with poly (lactic-co-glycolic acid) (PLGA) microparticles containing diprophylline particles: The 1st release phase ("burst release"), 2nd release phase (with an "about constant release rate") and 3rd release phase (which is again rapid and leads to complete drug exhaust). The behavior of single microparticles was monitored upon exposure to phosphate buffer pH 7.4, in particular with respect to their drug release and swelling behaviors. Diprophylline-loaded PLGA microparticles were prepared with a solid-in-oil-in-water solvent extraction/evaporation method. Tiny drug crystals were rather homogeneously distributed throughout the polymer matrix after manufacturing. Batches with "small" (63 µm), "medium-sized" (113 µm) and "large" (296 µm) microparticles with a practical drug loading of 5-7% were prepared. Importantly, each microparticle releases the drug "in its own way", depending on the exact distribution of the tiny drug crystals within the system. During the burst release, drug crystals with direct surface access rapidly dissolve. During the 2nd release phase tiny drug crystals (often) located in surface near regions which undergo swelling, are likely released. During the 3rd release phase, the entire microparticle undergoes substantial swelling. This results in high quantities of water present throughout the system, which becomes "gel-like". Consequently, the drug crystals dissolve, and the dissolved drug molecules rather rapidly diffuse through the highly swollen polymer gel.
Collapse
Affiliation(s)
- F Tamani
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - C Bassand
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - M C Hamoudi
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - F Danede
- Univ. Lille, USTL UMET UMR CNRS 8207, F-59650 Villeneuve d'Ascq, France
| | - J F Willart
- Univ. Lille, USTL UMET UMR CNRS 8207, F-59650 Villeneuve d'Ascq, France
| | - F Siepmann
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - J Siepmann
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France.
| |
Collapse
|