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  1. Article ; Online: Development and evaluation of a monolithic floating drug delivery system for acyclovir.

    Tavakoli, Naser / Varshosaz, Jaleh / Dorkoosh, Farid / Motaghi, Sedigheh / Tamaddon, Lana

    Chemical & pharmaceutical bulletin

    2011  Volume 60, Issue 2, Page(s) 172–177

    Abstract: Acyclovir (ACV), a model drug for this study, is one of the most effective drugs against viruses of the herpes group. Absorption of orally administered ACV is variable and incomplete, with a bioavailability of ca. 15-30%. The drug is absorbed in the ... ...

    Abstract Acyclovir (ACV), a model drug for this study, is one of the most effective drugs against viruses of the herpes group. Absorption of orally administered ACV is variable and incomplete, with a bioavailability of ca. 15-30%. The drug is absorbed in the duodenum after oral administration and hence, preparation of a floating drug delivery system (FDDS) for ACV may increase oral absorption of the drug. ACV matrix tablets (200 mg) containing an effervescent base (sodium bicarbonate and citric acid) and a binary combination of hydroxypropyl methylcellulose (HPMC) K4M with carbopol or sodium carboxymethyl cellulose (Na CMC) or polyvinylpyrrolidone (PVP) and/or sodium alginate were prepared by the direct compression method. The tablets were evaluated for physicochemical properties and in vitro floating ability (floating lag-time and duration), bioadhesiveness and drug release. The drug release studies were carried out in 0.1 N HCl (pH 1.2) at 37±0.5°C. At appropriate time intervals, samples were withdrawn and assayed spectrophotometrically at λ(max)=259 nm. The floating test showed tablets containing 15% effervescent base had a floating lag time of 10-30 s and a duration of floating time of 24 h. The formulations containing HPMC-PVP, HPMC-Na CMC, HPMC-carbopol, and HPMC-sodium alginate released about 60-90% of their drug content during a 12-h period. Increasing carbopol caused slower drug release. We concluded that the proposed tablets with 15% effervescent base, 20-30% HPMC, 30% Na CMC (and/or 20% PVP or 20% sodium alginate) showed good floating and drug release properties in vitro, and should be considered as FDDS for ACV.
    MeSH term(s) Acyclovir/administration & dosage ; Acyclovir/pharmacokinetics ; Antiviral Agents/administration & dosage ; Antiviral Agents/pharmacokinetics ; Biological Availability ; Drug Delivery Systems/standards ; Tablets/administration & dosage ; Tablets/chemistry
    Chemical Substances Antiviral Agents ; Tablets ; Acyclovir (X4HES1O11F)
    Language English
    Publishing date 2011-10-27
    Publishing country Japan
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 213307-6
    ISSN 1347-5223 ; 0009-2363
    ISSN (online) 1347-5223
    ISSN 0009-2363
    DOI 10.1248/cpb.60.172
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Thermoanalytical characterization of clindamycin-loaded intravitreal implants prepared by hot melt extrusion.

    Tamaddon, Lana / Mostafavi, Seyed Abolfazl / Karkhane, Reza / Riazi-Esfahani, Mohammad / Dorkoosh, Farid Abedin / Rafiee-Tehrani, Morteza

    Advanced biomedical research

    2015  Volume 4, Page(s) 147

    Abstract: Background: The aim of the present study was to evaluate a non-destructive fabrication method in for the development of sustained-release poly (L, D-lactic acid)-based biodegradable clindamycin phosphate implants for the treatment of ocular ... ...

    Abstract Background: The aim of the present study was to evaluate a non-destructive fabrication method in for the development of sustained-release poly (L, D-lactic acid)-based biodegradable clindamycin phosphate implants for the treatment of ocular toxoplasmosis.
    Materials and methods: The rod-shaped intravitreal implants with an average length of 5 mm and a diameter of 0.4 mm were evaluated for their physicochemical parameters. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), and nuclear magnetic resonance (1H NMR) studies were employed in order to study the characteristics of these formulations.
    Results: Drug content uniformity test confirmed the uniformity in different implant batches. Furthermore, the DSC, FTIR, and 1H NMR studies proved that the fabrication process did not have any destructive effects either on the drug or on the polymer structures.
    Conclusion: These studies showed that the developed sustained-release implants could be of interest for long-term sustained intraocular delivery of clindamycin, which can provide better patient compliance and also have good potential in terms of industrial feasibility.
    Language English
    Publishing date 2015-07-27
    Publishing country India
    Document type Journal Article
    ZDB-ID 2672524-1
    ISSN 2277-9175
    ISSN 2277-9175
    DOI 10.4103/2277-9175.161563
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis.

    Tamaddon, Lana / Mostafavi, S Abolfazl / Karkhane, Reza / Riazi-Esfahani, Mohammad / Dorkoosh, Farid Abedin / Rafiee-Tehrani, Morteza

    Advanced biomedical research

    2015  Volume 4, Page(s) 32

    Abstract: 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 ... ...

    Abstract 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.
    Language English
    Publishing date 2015-01-30
    Publishing country India
    Document type Journal Article
    ZDB-ID 2672524-1
    ISSN 2277-9175
    ISSN 2277-9175
    DOI 10.4103/2277-9175.150426
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Biorelevant media resistant co-culture model mimicking permeability of human intestine.

    Antoine, Delphine / Pellequer, Yann / Tempesta, Camille / Lorscheidt, Stefan / Kettel, Bernadette / Tamaddon, Lana / Jannin, Vincent / Demarne, Frédéric / Lamprecht, Alf / Béduneau, Arnaud

    International journal of pharmaceutics

    2015  Volume 481, Issue 1-2, Page(s) 27–36

    Abstract: Cell culture models are currently used to predict absorption pattern of new compounds and formulations in the human gastro-intestinal tract (GIT). One major drawback is the lack of relevant apical incubation fluids allowing mimicking luminal conditions ... ...

    Abstract Cell culture models are currently used to predict absorption pattern of new compounds and formulations in the human gastro-intestinal tract (GIT). One major drawback is the lack of relevant apical incubation fluids allowing mimicking luminal conditions in the GIT. Here, we suggest a culture model compatible with biorelevant media, namely Fasted State Simulated Intestinal Fluid (FaSSIF) and Fed State Simulated Intestinal Fluid (FeSSIF). Co-culture was set up from Caco-2 and mucus-secreting HT29-MTX cells using an original seeding procedure. Viability and cytotoxicity assays were performed following incubation of FeSSIF and FaSSIF with co-culture. Influence of biorelevant fluids on paracellular permeability or transporter proteins were also evaluated. Results were compared with Caco-2 and HT29-MTX monocultures. While Caco-2 viability was strongly affected with FeSSIF, no toxic effect was detected for the co-cultures in terms of viability and lactate dehydrogenase release. The addition of FeSSIF to the basolateral compartment of the co-culture induced cytotoxic effects which suggested the apical mucus barrier being cell protective. In contrast to FeSSIF, FaSSIF induced a slight increase of the paracellular transport and both tested media inhibited partially the P-gp-mediated efflux in the co-culture. Additionally, the absorptive transport of propranolol hydrochloride, a lipophilic β-blocker, was strongly affected by biorelevant fluids. This study demonstrated the compatibility of the Caco-2/HT29-MTX model with some of the current biorelevant media. Combining biorelevant intestinal fluids with features such as mucus secretion, adjustable paracellular and P-gp mediated transports, is a step forward to more realistic in-vitro models of the human intestine.
    MeSH term(s) ATP-Binding Cassette, Sub-Family B, Member 1/metabolism ; Biological Transport ; Caco-2 Cells ; Cell Survival ; Coculture Techniques ; HT29 Cells ; Humans ; Intestinal Absorption ; Intestinal Secretions ; Intestines/metabolism ; Mucus/metabolism ; Permeability ; Propranolol/pharmacology
    Chemical Substances ATP-Binding Cassette, Sub-Family B, Member 1 ; Propranolol (9Y8NXQ24VQ)
    Language English
    Publishing date 2015-03-15
    Publishing country Netherlands
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 428962-6
    ISSN 1873-3476 ; 0378-5173
    ISSN (online) 1873-3476
    ISSN 0378-5173
    DOI 10.1016/j.ijpharm.2015.01.028
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Development, characterizations and biocompatibility evaluations of intravitreal lipid implants.

    Tamaddon, Lana / Mostafavi, Abolfazl / Riazi-Esfahani, Mohammad / Karkhane, Reza / Aghazadeh, Sara / Rafiee-Tehrani, Morteza / Abedin Dorkoosh, Farid / Asadi Amoli, Fahimeh

    Jundishapur journal of natural pharmaceutical products

    2014  Volume 9, Issue 2, Page(s) e16414

    Abstract: Background: The treatment of posterior eye diseases is always challenging mainly due to inaccessibility of the region. Many drugs are currently delivered by repeated intraocular injections.: Objectives: The purpose of this study was to investigate ... ...

    Abstract Background: The treatment of posterior eye diseases is always challenging mainly due to inaccessibility of the region. Many drugs are currently delivered by repeated intraocular injections.
    Objectives: The purpose of this study was to investigate the potential applications of natural triglycerides as alternative carriers to synthetic polymers in terms of drug release profile and also biocompatibility for intraocular use.
    Materials and methods: In vitro/in vivo evaluations of intravitreal implants fabricated from the physiological lipid, glyceride tripalmitate containing clindamycin phosphate as a model drug was performed. The micro-implants with average diameter of 0.4 mm were fabricated via a hot melt extrusion method. The extrudates were analyzed using scanning electron microscopy, differential scanning calorimetry, and in vitro drug dissolution studies. For biocompatibility, the implants were implanted into rabbit eyes. Clinical investigations including fundus observations, electroretinography as well as histological evaluations were performed.
    Results: In vitro tests guaranteed usefulness of the production method for preparing the homogenous mixture of the drug and lipid without affecting thermal and crystalinity characteristics of the components. In vitro releases indicated a bi-phasic pattern for lower lipid ratios, which were completed by the end of day three. With higher lipid ratios, more controlled release profiles were achieved until about ten days for a lipid ratio of 95%. Clinical observations did not show any abnormalities up to two months after implantation into the rabbit eye.
    Conclusions: These results suggest that although the implant could not adequately retard release of the present drug model yet, due to good physical characteristics and in vivo biocompatibility, it can represent a suitable device for loading wide ranges of therapeutics in treatment of many kinds of retinochoroidal disorders.
    Language English
    Publishing date 2014-04-07
    Publishing country Iran
    Document type Journal Article
    ZDB-ID 3028403-X
    ISSN 2228-7876 ; 1735-7780
    ISSN (online) 2228-7876
    ISSN 1735-7780
    DOI 10.17795/jjnpp-16414
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Design and development of intraocular polymeric implant systems for long-term controlled-release of clindamycin phosphate for toxoplasmic retinochoroiditis

    Lana Tamaddon / S Abolfazl Mostafavi / Reza Karkhane / Mohammad Riazi-Esfahani / Farid Abedin Dorkoosh / Morteza Rafiee-Tehrani

    Advanced Biomedical Research, Vol 4, Iss 1, Pp 32-

    2015  Volume 32

    Abstract: 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 ... ...

    Abstract 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.
    Keywords Clindamycin phosphate ; intraocular implant ; PLA ; PLGA ; Medicine ; R ; Biology (General) ; QH301-705.5
    Subject code 660
    Language English
    Publishing date 2015-01-01T00:00:00Z
    Publisher Wolters Kluwer Medknow Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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