Effect of carrageenan on poloxamer-based in situ gel for vaginal use: Improved in vitro and in vivo sustained-release properties

Yu, Liu; Zhu, Yiying; Wei, Gang; Lu, Weiyue

doi:10.1016/j.ejps.2009.02.022

Cited by 122 publications

(61 citation statements)

References 27 publications

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“…Unfortunately, more recent phase III clinical trials of Carraguard demonstrated that this carrageenan-based product was not an effective inhibitor of HIV-1 transmission (86). Although carrageenan is no longer under consideration as an active microbicide, it is still being explored as an "active excipient" for future topical vaginal and rectal microbicides due to its desirable rheologic properties (55). Therefore, combination studies focused on carrageenan paired with future candidate microbicide agents may still be necessary precursors to clinical trials of safety and efficacy.…”

Section: Preclinical Microbicide Combination Studiesmentioning

confidence: 99%

Combinatorial Approaches to the Prevention and Treatment of HIV-1 Infection

Pirrone

Thakkar

Jacobson

et al. 2011

Antimicrob Agents Chemother

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The discovery of the human immunodeficiency virus type 1 (HIV-1) in 1982 soon led to the identification and development of antiviral compounds to be used in treatment strategies for infected patients. Early in the epidemic, drug monotherapies frequently led to treatment failures because the virus quickly developed resistance to the single drug. Following the advent of highly active antiretroviral therapy (HAART) in 1995, dramatic improvements in HIV-1-infected patient health and survival were realized as more refined combination therapies resulted in reductions in viral loads and increases in CD4 ؉ T-cell counts. In the absence of an effective vaccine, prevention of HIV-1 infection has also gained traction as an approach to curbing the pandemic. The development of compounds as safe and effective microbicides has intensified and has focused on blocking the transmission of HIV-1 during all forms of sexual intercourse. Initial preclinical investigations and clinical trials of microbicides focused on single compounds effective against HIV-1. However, the remarkable successes achieved using combination therapy to treat systemic HIV-1 infection have subsequently stimulated the study and development of combination microbicides that will simultaneously inhibit multiple aspects of the HIV-1 transmission process by targeting incoming viral particles, virus-infected cells, and cells susceptible to HIV-1 infection. This review focuses on existing and developing combination therapies, covering preclinical development, in vitro and in vivo efficacy studies, and subsequent clinical trials. The shift in focus within the microbicide development field from single compounds to combination approaches is also explored.

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Section: Preclinical Microbicide Combination Studiesmentioning

confidence: 99%

Combinatorial Approaches to the Prevention and Treatment of HIV-1 Infection

Pirrone

Thakkar

Jacobson

et al. 2011

Antimicrob Agents Chemother

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“…Total nine different media were investigated reported in literature e.g. distilled water pH7 (DW), citrate buffer B.P pH4.8 (CBBP), normal saline pH4.8 (SLN), citrate buffer pH 4.8 (CB) [8], acetate buffer pH6 (AB), acetate buffer with dioxane pH4.8 (ABWD) [9], phosphate citrate buffer pH4.8 (PCB) [10], modified citrate buffer pH5.5(MCB) [11] and simulated vaginal fluid pH4.2 (SVF) [12].…”

Section: In Vitro Drug Releasementioning

confidence: 99%

Development of Mucoadhesive Gel Microbicide to Target Mucosal HIV Reservoirs

Shegokar¹,

Singh²

2014

J HIV Clin Sci Res

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The wide use of microbicide is mainly depends on its effectiveness, less frequent application, ready availability and most importantly cost. The aim of this work was to develop affordable microbicide mucoadhesive gel formulation of synthetic anti HIV drug, stavudine and to characterise it in terms of its physical properties, mucoadhesiveness and spreadability. The purpose of the present study was also to compare different dissolution media used for in vitro release of vaginal dosage form. The gels were tested for antimicrobial, spermicidal and anti-HIV activity. Gels prepared using Carbopols and Polycarbophil were transparent and homogenous and had excellent mucoadhesion index -and showed fast drug release profile. Gels showed very good antimicrobial action against pathological microorganism.to combat costs, side effects, and local tissue drug distribution limitations. In this research, an attempt was made to formulate stavudine, a synthetic thymidine nucleoside analogue mucoadhesive microbicide gel. Three polymers were used at three different concentrations to produce gels. Prepared gels were evaluated mainly for their mucoadhesiveness, drug release profile and antimicrobial action.

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“…The triblock copolymer poloxamer 407 has been examined extensively as an in situ gelling system but the fast erosion of these gels in aqueous environments and the nonbiodegradability of the polymer has limited its use as a sustained release system (18,19). Attempts to increase the stability of poloxamer through the addition of copolymers such as pluronic 25R4 (20), dextran (21), carrageenan (22), and methylcellulose (23) have had limited success. Biodegradable triblock copolymers made up of polycaprolactone (PCL) and polyethyleneglycol (PEG) (i.e., PEG-PCL-PEG, PCL-PEG-PCL) are reported to be stable in aqueous conditions but the crystallinity of the PCL blocks slowed degradation (24)(25)(26).…”

Section: Introductionmentioning

confidence: 99%

Novel Injectable Pentablock Copolymer Based Thermoresponsive Hydrogels for Sustained Release Vaccines

Bobbala

Tamboli²,

McDowell

et al. 2015

AAPS J

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Abstract. The need for multiple vaccinations to enhance the immunogenicity of subunit vaccines may be reduced by delivering the vaccine over an extended period of time. Here, we report two novel injectable pentablock copolymer based thermoresponsive hydrogels made of polyethyleneglycol-polycaprolactonepolylactide-polycaprolactone-polyethyleneglycol (PEG-PCL-PLA-PCL-PEG) with varying ratios of polycaprolactone (PCL) and polylactide (PLA), as single shot sustained release vaccines. Pentablock copolymer hydrogels were loaded with vaccine-encapsulated poly lactic-co-glycolic acid nanoparticles (PLGA-NP) or with the soluble vaccine components. Incorporation of PLGA-NP into the thermoresponsive hydrogels increased the complex viscosity of the gels, lowered the gelation temperature, and minimized the burst release of antigen and adjuvants. The two pentablock hydrogels stimulated both cellular and humoral responses. The addition of PLGA-NP to the hydrogels sustained immune responses for up to 49 days. The polymer with a higher ratio of PCL to PLA formed a more rigid gel, induced stronger immune responses, and stimulated effective anti-tumor responses in a prophylactic melanoma tumor model.

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Effect of carrageenan on poloxamer-based in situ gel for vaginal use: Improved in vitro and in vivo sustained-release properties

Cited by 122 publications

References 27 publications

Combinatorial Approaches to the Prevention and Treatment of HIV-1 Infection

Combinatorial Approaches to the Prevention and Treatment of HIV-1 Infection

Development of Mucoadhesive Gel Microbicide to Target Mucosal HIV Reservoirs

Novel Injectable Pentablock Copolymer Based Thermoresponsive Hydrogels for Sustained Release Vaccines

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