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Abstract
Microbicides are antiseptic topical drugs that help directly or indirectly inhibit the penetration of an infectious agent into the human body, thereby preventing the sexual transmission of HIV-infection and other sexually transmitted diseases. Microbicides have an antiviral mechanism of action in the sexual transmission of HIV and affect the components of mucosal immunity in the vagina. In this article, the pharmaceutical and biomedical aspects of microbicide application are examined and diverse classifications of microbicides are presented. For each group of chemicals, the most important representatives and their mechanisms of action are described. This article also presents the structure and function of mucosal immunity, and shows the importance of the mucosal immune response in the sexual transmission of HIV. This work also exhibits the experimental models for testing of candidate microbicides. For each compound described, a review of preclinical research and clinical trials is provided, covering its development as a microbicide. This paper gives an overview of microbicides, a new class of chemically diverse immunobiological medications reducing the risk of sexual transmission of HIV. The use of microbicides is believed to curb the HIV/AIDS epidemic in the nearest future.
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Ham AS, Nugent ST, Peters JJ, Katz DF, Shelter CM, Dezzutti CS, Boczar AD, Buckheit KW, Buckheit RW. The rational design and development of a dual chamber vaginal/rectal microbicide gel formulation for HIV prevention. Antiviral Res 2015; 120:153-64. [PMID: 26093158 DOI: 10.1016/j.antiviral.2015.06.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/15/2015] [Accepted: 06/16/2015] [Indexed: 10/23/2022]
Abstract
The DuoGel™ was developed for safe and effective dual chamber administration of antiretroviral drugs to reduce the high incidence of HIV transmission during receptive vaginal and anal intercourse. The DuoGel™s containing IQP-0528, a non-nucleoside reverse transcriptase inhibitor (NNRTI), were formulated from GRAS excipients approved for vaginal and rectal administration. The DuoGel™s were evaluated based upon quantitative physicochemical and biological evaluations defined by a Target Product Profile (TPP) acceptable for vaginal and rectal application. From the two primary TPP characteristics defined to accommodate safe rectal administration three DuoGel™ formulations (IQB3000, IQB3001, and IQB3002) were developed at pH 6.00 and osmolality ⩽400mmol/kg. The DuoGel™s displayed no in vitro cellular or bacterial toxicity and no loss in viability in ectocervical and colorectal tissue. IQB3000 was removed from consideration due to reduced NNRTI delivery (∼65% reduction) and IQB3001 was removed due to increase spread resulting in leakage. IQB3002 containing IQP-0528 was defined as our lead DuoGel™ formulation, possessing potent activity against HIV-1 (EC50=10nM). Over 12month stability evaluations, IQB3002 maintained formulation stability. This study has identified a lead DuoGel™ formulation that will safely deliver IQP-0528 to prevent sexual HIV-1 transmission in the vagina and rectum.
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Affiliation(s)
| | | | | | | | - Cory M Shelter
- Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
| | - Charlene S Dezzutti
- University of Pittsburgh, Pittsburgh, PA 15213, USA; Magee-Womens Research Institute, Pittsburgh, PA 15213, USA
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Chhikara BS, Rao MS, Rao VK, Kumar A, Buckheit KW, Buckheit Jr. RW, Parang K. Carbocyclodipeptides as modified nucleosides: synthesis and anti-HIV activities. CAN J CHEM 2014; 92:1145-1149. [DOI: 10.1139/cjc-2014-0356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2024]
Abstract
A new class of nucleoside analogues were synthesized using cyclic dipeptides and modified 2′-deoxyfuranoribose sugars to introduce flexibility by peptides in place of common nucleoside bases and to determine their biological properties. The synthesis was carried out by coupling of a protected ribose sugar with synthesized dipeptides in the presence of hexamethyldisilazane and trimethylsilyltriflate. The final products were characterized by NMR and high-resolution MS-TOF spectroscopy. The compounds were evaluated for anti-HIV activities. 1-(4-Azido-5-(hydroxymethyl)tetrahydrofuran-2-yl)-3,6-diisopropylpiperazine-2,5-dione (compound 14) containing 3- and 6-isopropyl groups in the base and 3′-azide (EC50 = 1.96 μmol/L) was the most potent compound among all of the synthesized analogs.
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Affiliation(s)
- Bhupender S. Chhikara
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, RI 02881, USA
| | - M. Sudershan Rao
- Department of Chemistry, Birla Institute of Technology and Science, Pilani 333031 Rajasthan, India
| | - V. Kameshwara Rao
- Department of Chemistry, Birla Institute of Technology and Science, Pilani 333031 Rajasthan, India
| | - Anil Kumar
- Department of Chemistry, Birla Institute of Technology and Science, Pilani 333031 Rajasthan, India
| | - Karen W. Buckheit
- ImQuest BioSciences Inc., 7340 Executive Way, Suite R, Frederick, MD 21704, USA
| | | | - Keykavous Parang
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, RI 02881, USA
- Department of Chemistry, Birla Institute of Technology and Science, Pilani 333031 Rajasthan, India
- Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, 9401 Jeronimo Road, Irvine, CA 92618, USA
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Pemmaraju B, Agarwal HK, Oh D, Buckheit KW, Buckheit RW, Tiwari R, Parang K. Synthesis and Biological Evaluation of 5'- O-Dicarboxylic Fatty Acyl Monoester Derivatives of Anti-HIV Nucleoside Reverse Transcriptase Inhibitors. Tetrahedron Lett 2014; 55:1983-1986. [PMID: 24791029 PMCID: PMC4001930 DOI: 10.1016/j.tetlet.2014.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A number of 5'-O-dicarboxylic fatty acyl monoester derivatives of 3'-azido-3'-deoxythymidine (zidovudine, AZT), 2',3'-didehydro-2',3'-dideoxythymidine (stavudine, d4T), and 3'-fluoro-3'-deoxythymidine (alovudine, FLT) were synthesized to improve the lipophilicity and potentially the cellular delivery of parent polar 2', 3'-dideoxynucleoside (ddN) analogues. The compounds were evaluated for their anti-HIV activity. Three different fatty acids with varying chain length of suberic acid (octanedioic acid), sebacic acid (decanedioic acid), and dodecanedioic acid were used for the conjugation with the nucleosides. The compounds were evaluated for anti-HIV activity and cytotoxicity. All dicarboxylic ester conjugates of nucleosides exhibited significantly higher anti-HIV activity than that of the corresponding parent nucleoside analogs. Among all the tested conjugates, 5'-O-suberate derivative of AZT (EC50 = 0.10 nM) was found to be the most potent compound and showed 80-fold higher anti-HIV activity than AZT without any significant toxicity (TC50 > 500 nM).
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Affiliation(s)
- Bhanu Pemmaraju
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - Hitesh K Agarwal
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - Donghoon Oh
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - Karen W. Buckheit
- ImQuest BioSciences Inc. 7340 Executive Way, Suite R, Frederick, MD, 21704, United States
| | - Robert W. Buckheit
- ImQuest BioSciences Inc. 7340 Executive Way, Suite R, Frederick, MD, 21704, United States
| | - Rakesh Tiwari
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
- School of Pharmacy, Chapman University, Orange, CA, 92618, United States
| | - Keykavous Parang
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
- School of Pharmacy, Chapman University, Orange, CA, 92618, United States
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Ham AS, Lustig W, Yang L, Boczar A, Buckheit KW, Buckheit Jr RW. In vitro and ex vivo evaluations on transdermal delivery of the HIV inhibitor IQP-0410. PLoS One 2013; 8:e75306. [PMID: 24058672 PMCID: PMC3776786 DOI: 10.1371/journal.pone.0075306] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 08/12/2013] [Indexed: 11/24/2022] Open
Abstract
The aim of this study was to investigate the physicochemical and in vitro/ex vivo characteristics of the pyrmidinedione IQP-0410 formulated into transdermal films. IQP-0410 is a potent therapeutic anti-HIV nonnucleoside reverse transcriptase inhibitor that would be subjected to extensive first pass metabolism, through conventional oral administration. Therefore, IQP-0410 was formulated into ethyl cellulose/HPMC-based transdermal films via solvent casting. In mano evaluations were performed to evaluate gross physical characteristics. In vitro release studies were performed in both Franz cells and USP-4 dissolution vessels. Ex vivo release and permeability assays were performed on human epidermal tissue models, and the permeated IQP-0410 was collected for in vitro HIV-1 efficacy assays in CEM-SS cells and PBMCs. Film formulation D3 resulted in pliable, strong transdermal films that were loaded with 2% (w/w) IQP-0410. Composed of 60% (w/w) ethyl cellulose and 20% (w/w) HPMC, the films contained < 1.2% (w/w) of water and were hygroscopic resulting in significant swelling under humid conditions. The water permeable nature of the film resulted in complete in vitro dissolution and drug release in 26 hours. When applied to ex vivo epidermal tissues, the films were non-toxic to the tissue and also were non-toxic to HIV target cells used in the in vitro efficacy assays. Over a 3 day application, the films delivered IQP-0410 through the skin tissue at a zero-order rate of 0.94 ± 0.06 µg/cm2/hr with 134 ± 14.7 µM collected in the basal media. The delivered IQP-0410 resulted in in vitro EC50 values against HIV-1 of 2.56 ± 0.40 nM (CEM-SS) and 0.58 ± 0.03 nM (PBMC). The film formulation demonstrated no significant deviation from target values when packaged in foil pouches under standard and accelerated environmental conditions. It was concluded that the transdermal film formulation was a potentially viable method of administering IQP-0410 that warrants further development.
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Affiliation(s)
- Anthony S. Ham
- ImQuest BioSciences Inc., Frederick, Maryland, United States of America
- * E-mail:
| | - William Lustig
- ImQuest BioSciences Inc., Frederick, Maryland, United States of America
| | - Lu Yang
- ImQuest BioSciences Inc., Frederick, Maryland, United States of America
| | - Ashlee Boczar
- ImQuest BioSciences Inc., Frederick, Maryland, United States of America
| | - Karen W. Buckheit
- ImQuest BioSciences Inc., Frederick, Maryland, United States of America
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Agarwal HK, Buckheit KW, Buckheit RW, Parang K. Synthesis and anti-HIV activities of symmetrical dicarboxylate esters of dinucleoside reverse transcriptase inhibitors. Bioorg Med Chem Lett 2012; 22:5451-4. [PMID: 22858097 DOI: 10.1016/j.bmcl.2012.07.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 07/09/2012] [Indexed: 10/28/2022]
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Factors Important to the Prioritization and Development of Successful Topical Microbicides for HIV-1. Mol Biol Int 2012; 2012:781305. [PMID: 22848826 PMCID: PMC3403474 DOI: 10.1155/2012/781305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 05/11/2012] [Indexed: 12/20/2022] Open
Abstract
Significant advancements in topical microbicide development have occurred since the prevention strategy was first described as a means to inhibit the sexual transmission of HIV-1. The lack of clinical efficacy of the first generation microbicide products has focused development attention on specific antiretroviral agents, and these agents have proven partially successful in human clinical trials. With greater understanding of vaginal and rectal virus infection, replication, and dissemination, better microbicide products and delivery strategies should result in products with enhanced potency. However, a variety of development gaps exist which relate to product dosing, formulation and delivery, and pharmacokinetics and pharmacodynamics which must be better understood in order to prioritize microbicide products for clinical development. In vitro, ex vivo, and in vivo models must be optimized with regard to these development gaps in order to put the right product at the right place, at the right time, and at the right concentration for effective inhibition of virus transmission. As the microbicide field continues to evolve, we must harness the knowledge gained from unsuccessful and successful clinical trials and development programs to continuously enhance our preclinical development algorithms.
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UC781 microbicide gel retains anti-HIV activity in cervicovaginal lavage fluids collected following twice-daily vaginal application. Antimicrob Agents Chemother 2012; 56:3592-6. [PMID: 22508307 DOI: 10.1128/aac.00452-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The potent nonnucleoside reverse transcriptase inhibitor UC781 has been safety tested as a vaginal microbicide gel formulation for prevention of HIV-1 sexual transmission. To investigate whether UC781 retained anti-infective activity following exposure to the female genital tract, we conducted an ex vivo analysis of the UC781 levels and antiviral activity in cervicovaginal lavage (CVL) fluids from 25 Thai women enrolled in a 14-day safety trial of twice-daily vaginal application of two concentrations of the UC781 microbicide gel. CVL samples were collected from women in the 0.1% (n = 5), 0.25% (n = 15), and placebo (n = 5) gel arms following the first application of gel (T(15 min)) and 8 to 24 h after the final application (T(8-24 h)) and separated into cell-free (CVL-s) and pelletable (CVL-p) fractions. As UC781 is highly hydrophobic, there were significantly higher levels of UC781 in the CVL-p samples than in the CVL-s samples for the UC781 gel arms. In T(8-24 h) CVL-p samples, 2/5 and 13/15 samples collected from the 0.1% and 0.25% UC781 gel arms, respectively, efficiently blocked infection with ≥ 4 log(10) 50% tissue culture infective dose (TCID(50)) of a CCR5-tropic CRF01_AE HIV-1 virus stock. Independent of the arm, the 11 CVL-p samples with UC781 levels of ≥ 5 μg/CVL sample reduced infectious HIV by ≥ 4 log(10) TCID(50). Our results suggest that the levels and anti-infective activities of UC781 gel formulations are likely to be associated with a cellular or pelletable component in CVL samples. Therefore, cellular and pelletable fractions should be assayed for drug levels and anti-infective activity in preclinical studies of candidate microbicides.
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Ham AS, Rohan LC, Boczar A, Yang L, W Buckheit K, Buckheit RW. Vaginal film drug delivery of the pyrimidinedione IQP-0528 for the prevention of HIV infection. Pharm Res 2012; 29:1897-907. [PMID: 22392331 DOI: 10.1007/s11095-012-0715-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 02/20/2012] [Indexed: 11/29/2022]
Abstract
PURPOSE Polymeric quick-dissolving films were developed as a solid dosage topical microbicide formulation for the vaginal delivery of the highly potent and non-toxic, dual-acting HIV nonnucleoside reverse transcriptase inhibitor (NNRTI) pyrimidinedione, IQP-0528. METHODS Formulated from approved excipients, a polyvinyl alcohol (PVA) based film was manufactured via solvent casting methods. The film formulations were evaluated based upon quantitative physicochemical evaluations defined by a Target Product Profile (TPP) RESULTS: Films dosed with 0.1% (w/w) of IQP-0528 disintegrated within 10 min with over 50% of drug released and near 100% total drug released after 30 min. The IQP-0528 films were found to be non-toxic in in vitro CEM-SS and PBMC cell-based assays and biologically active with sub-nanomolar efficacy against HIV-1 infection. In a 12 month stability protocol, the IQP-0528 films demonstrated no significant degradation at International Conference on Harmonization (ICH) recommended standard (25°C/65% relative humidity (R.H.)) and accelerated (40°C/75% R.H.) environmental conditions. CONCLUSIONS Based on the above evaluations, a vaginal film formulation has been identified as a potential solid dosage form for the vaginal delivery of the topical microbicide candidate IQP-0528.
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Affiliation(s)
- Anthony S Ham
- ImQuest BioSciences Inc., 7340 Executive Way, Suite R, Frederick, Maryland 21704, USA.
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Development of dual-acting pyrimidinediones as novel and highly potent topical anti-HIV microbicides. Antimicrob Agents Chemother 2011; 55:5243-54. [PMID: 21896906 DOI: 10.1128/aac.05237-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the absence of an effective vaccine against the human immunodeficiency virus (HIV), topical microbicides to prevent the sexual transmission of HIV represent an important strategy to prevent the continued spread of infection. The recent trend in the development of new microbicide candidates includes the utilization of FDA-approved therapeutic drugs that target the early stages of the HIV life cycle, including entry inhibitors and reverse transcriptase inhibitors. We have investigated 12 pyrimidinedione compounds with potent HIV activities and their abilities to inhibit both virus entry and reverse transcription, in an effort to determine a lead microbicide for product development. The candidate compounds were evaluated for efficacy against subtype B, C, and E clinical virus strains in fresh human peripheral blood mononuclear cells and against CCR5-tropic virus strains in both monocyte-macrophages and dendritic cells. Microbicide-specific biological assays and toxicity evaluations were also performed in a variety of established and fresh human cells as well as against Lactobacillus strains common to the vaginal environment. These evaluations resulted in the identification of congeners with cyclopropyl and cyclobutyl substituents at the N-1 of the pyrimidinedione as the most active molecules in the structure-activity relationship series. The pyrimidinediones represent excellent microbicide candidates in light of their significantly high efficacies against HIV-1 (subnanomolar concentration range), potencies (therapeutic index, >1 million), solubility profiles, and dual mechanism of antiviral action that includes two early steps of virus replication prior to the integration of the virus that are considered most important for microbicidal activity.
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Buckheit RW, Watson KM, Morrow KM, Ham AS. Development of topical microbicides to prevent the sexual transmission of HIV. Antiviral Res 2010; 85:142-58. [PMID: 19874851 PMCID: PMC2815091 DOI: 10.1016/j.antiviral.2009.10.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 10/12/2009] [Accepted: 10/16/2009] [Indexed: 01/07/2023]
Abstract
Women comprise almost 50% of the population of people living with HIV and the majority of these women contracted the virus through sexual transmission in monogamous relationships in the developing world. In these environments, where women are not empowered to protect themselves through the negotiation of condom use, effective means of preventing HIV transmission are urgently needed. In the absence of an approved and effective vaccine, microbicides have become the strategy of choice to provide women with the ability to prevent HIV transmission from their infected partners. Topical microbicides are agents specifically developed and formulated for use in either the vaginal or rectal environment that prevent infection by sexually transmitted infectious organisms, including pathogenic viruses, bacteria and fungi. Although a microbicidal product will have many of the same properties as other anti-infective agents and would be similarly developed through human clinical trials, microbicide development bears its own challenges related to formulation and delivery and the unique environment in which the product must act, as well as the requirement to develop a product that is acceptable to the user. Herein, perspectives based on preclinical and clinical microbicide development experience, which have led to an evolving microbicide development algorithm, will be discussed. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of anti-retroviral drug discovery and development, Vol 85, issue 1, 2010.
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Affiliation(s)
- Robert W Buckheit
- ImQuest BioSciences, Inc., 7340 Executive Way, Suite R, Frederick, MD 21704, USA.
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Small molecule inhibitors of HIV RT Ribonuclease H. Bioorg Med Chem Lett 2009; 20:398-402. [PMID: 19939680 DOI: 10.1016/j.bmcl.2009.10.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 10/07/2009] [Accepted: 10/09/2009] [Indexed: 11/21/2022]
Abstract
Two classes of compounds, thiocarbamates 1 and triazoles 2, have been identified as HIV RT RNase H inhibitors using a novel FRET-based HTS assay. The potent analogs in each series exhibited selectivity and were active in cell-based assays. In addition, saturable, 1:1 stoichiometric binding to target was established and time of addition studies were consistent with inhibition of RT-mediated HIV replication.
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