Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis
Background: The release of the anti-toxoplasmosis drug, clindamycin phosphate, from intraocular implants of the biodegradable polymers poly (D, L-lactic acid) (PLA) and poly (D, L-lactide-co-glycolide) (PLGA) has been studied in vitro. Materials and Methods: The preparation of the implants was perf...
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2015-01-01
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| Series: | Advanced Biomedical Research |
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| Online Access: | http://www.advbiores.net/article.asp?issn=2277-9175;year=2015;volume=4;issue=1;spage=32;epage=32;aulast=Tamaddon |
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| author | Lana Tamaddon S Abolfazl Mostafavi Reza Karkhane Mohammad Riazi-Esfahani Farid Abedin Dorkoosh Morteza Rafiee-Tehrani |
| author_facet | Lana Tamaddon S Abolfazl Mostafavi Reza Karkhane Mohammad Riazi-Esfahani Farid Abedin Dorkoosh Morteza Rafiee-Tehrani |
| author_sort | Lana Tamaddon |
| collection | DOAJ |
| description | Background: The release of the anti-toxoplasmosis drug, clindamycin phosphate, from intraocular implants of the biodegradable polymers poly (D, L-lactic acid) (PLA) and poly (D, L-lactide-co-glycolide) (PLGA) has been studied in vitro.
Materials and Methods: The preparation of the implants was performed by a melt-extrusion method. The developed extrudates were characterized and compared in in-vitro release profiles for elucidating the drug release mechanism. The formulations containing up to 40% w/w of drug were prepared. Release data in phosphate buffer (pH 7.4) were analyzed by high performance liquid chromatography. The release kinetics were fitted to the zero-order, Higuchi′s square-root, first order and the Korsmeyer-Peppas empirical equations for the estimation of various parameters of the drug release curves. Degradation of implants was also investigated morphologically with time (Scanning Electron Microscopy).
Results: It was observed that, the release profiles for the formulations exhibit a typical biphasic profile for bulk-eroding systems, characterized by a first phase of burst release (in first 24 hrs), followed by a phase of slower release. The duration of the secondary phase was found to be proportional to the molecular weight and monomer ratio of copolymers and also polymer-to-drug ratios. It was confirmed that Higuchi and first-order kinetics were the predominant release mechanisms than zero order kinetic. The Korsmeyer-Peppas exponent (n) ranged between 0.10 and 0.96. This value, confirmed fickian as the dominant mechanism for PLA formulations (n ≤ 0.45) and the anomalous mechanism, for PLGAs (0.45 < n < 0.90).
Conclusion: The implant of PLA (I.V. 0.2) containing 20% w/w of clindamycin, was identified as the optimum formulation in providing continuous efficient in-vitro release of clindamycin for about 5 weeks. |
| first_indexed | 2024-12-16T17:54:28Z |
| format | Article |
| id | doaj.art-c7c9583e324142a59cfe28e910d27cfe |
| institution | Directory Open Access Journal |
| issn | 2277-9175 2277-9175 |
| language | English |
| last_indexed | 2024-12-16T17:54:28Z |
| publishDate | 2015-01-01 |
| publisher | Wolters Kluwer Medknow Publications |
| record_format | Article |
| series | Advanced Biomedical Research |
| spelling | doaj.art-c7c9583e324142a59cfe28e910d27cfe2022-12-21T22:22:12ZengWolters Kluwer Medknow PublicationsAdvanced Biomedical Research2277-91752277-91752015-01-0141323210.4103/2277-9175.150426Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditisLana TamaddonS Abolfazl MostafaviReza KarkhaneMohammad Riazi-EsfahaniFarid Abedin DorkooshMorteza Rafiee-TehraniBackground: The release of the anti-toxoplasmosis drug, clindamycin phosphate, from intraocular implants of the biodegradable polymers poly (D, L-lactic acid) (PLA) and poly (D, L-lactide-co-glycolide) (PLGA) has been studied in vitro. Materials and Methods: The preparation of the implants was performed by a melt-extrusion method. The developed extrudates were characterized and compared in in-vitro release profiles for elucidating the drug release mechanism. The formulations containing up to 40% w/w of drug were prepared. Release data in phosphate buffer (pH 7.4) were analyzed by high performance liquid chromatography. The release kinetics were fitted to the zero-order, Higuchi′s square-root, first order and the Korsmeyer-Peppas empirical equations for the estimation of various parameters of the drug release curves. Degradation of implants was also investigated morphologically with time (Scanning Electron Microscopy). Results: It was observed that, the release profiles for the formulations exhibit a typical biphasic profile for bulk-eroding systems, characterized by a first phase of burst release (in first 24 hrs), followed by a phase of slower release. The duration of the secondary phase was found to be proportional to the molecular weight and monomer ratio of copolymers and also polymer-to-drug ratios. It was confirmed that Higuchi and first-order kinetics were the predominant release mechanisms than zero order kinetic. The Korsmeyer-Peppas exponent (n) ranged between 0.10 and 0.96. This value, confirmed fickian as the dominant mechanism for PLA formulations (n ≤ 0.45) and the anomalous mechanism, for PLGAs (0.45 < n < 0.90). Conclusion: The implant of PLA (I.V. 0.2) containing 20% w/w of clindamycin, was identified as the optimum formulation in providing continuous efficient in-vitro release of clindamycin for about 5 weeks.http://www.advbiores.net/article.asp?issn=2277-9175;year=2015;volume=4;issue=1;spage=32;epage=32;aulast=TamaddonClindamycin phosphateintraocular implantPLAPLGA |
| spellingShingle | Lana Tamaddon S Abolfazl Mostafavi Reza Karkhane Mohammad Riazi-Esfahani Farid Abedin Dorkoosh Morteza Rafiee-Tehrani Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis Advanced Biomedical Research Clindamycin phosphate intraocular implant PLA PLGA |
| title | Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis |
| title_full | Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis |
| title_fullStr | Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis |
| title_full_unstemmed | Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis |
| title_short | Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis |
| title_sort | design and development of intraocular polymeric implant systems for long term controlled release of clindamycin phosphate for toxoplasmic retinochoroiditis |
| topic | Clindamycin phosphate intraocular implant PLA PLGA |
| url | http://www.advbiores.net/article.asp?issn=2277-9175;year=2015;volume=4;issue=1;spage=32;epage=32;aulast=Tamaddon |
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