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1.
Prev Sci ; 19(8): 1079-1090, 2018 11.
Article in English | MEDLINE | ID: mdl-30022356

ABSTRACT

The World Health Organisation advocates a direct focus on adolescent men in reducing adolescent pregnancy; however, no trials have been conducted. This trial (ISRCTN11632300; NCT02092480) determines whether a novel Relationship and Sexuality Educational intervention, If I Were Jack, is acceptable and feasible to implement in mixed sex UK classrooms. The intervention is a teacher-delivered intervention that emphasises male alongside female  responsibility in preventing unintended pregnancies and is designed to prevent unprotected sex. The trial was a parallel-group cluster randomised controlled feasibility trial with embedded process and cost evaluation in eight secondary schools (unit of randomisation) among 831 pupils (mean age 14) in Northern Ireland, alongside a qualitative evaluation of transferability in ten schools in Scotland, Wales and England. The sampling strategy was a maximum variation quota sample designed to capture a range of school management types. Four schools were randomised to each arm and the control arm continued with usual practice. Study duration was 12 months (from November 2014), with follow-up 9 months post-baseline. Results demonstrated that the intervention was acceptable to schools, pupils and teachers, and could be feasibly implemented, cost-effectively, with minor enhancements. The between-group difference in incidence of unprotected sex (primary outcome at pupil level) of 1.3% (95% CI 0.5-2.2) by 9 months demonstrated a potential effect size consistent with those reported to have had meaningful impact on teenage pregnancy. The study responds to global health policy for a paradigm shift towards inclusion of men in the achievement of sexual and reproductive health goals in a practical way by demonstrating that a gender-sensitive as well as a gender transformative intervention targeting males to prevent teenage pregnancy is acceptable to adolescent men and women and implementable in formal education structures. If I Were Jack now merits further effectiveness testing.


Subject(s)
Pregnancy in Adolescence/prevention & control , Schools , Sex Education/methods , Adolescent , Cluster Analysis , Feasibility Studies , Female , Humans , Male , Pregnancy , United Kingdom
2.
BMJ Open ; 8(7): e022128, 2018 07 28.
Article in English | MEDLINE | ID: mdl-30056390

ABSTRACT

INTRODUCTION: Teenage pregnancy remains a worldwide health concern which is an outcome of, and contributor to, health inequalities. The need for gender-aware interventions with a focus on males in addressing teenage pregnancy has been highlighted as a global health need by WHO and identified in systematic reviews of (relationship and sexuality education (RSE)). This study aims to test the effectiveness of an interactive film-based RSE intervention, which draws explicit attention to the role of males in preventing an unintended pregnancy by reducing unprotected heterosexual teenage sex among males and females under age 16 years. METHODS AND ANALYSIS: A phase III cluster randomised trial with embedded process and economic evaluations. If I Were Jack encompasses a culturally sensitive interactive film, classroom materials, a teacher-trainer session and parent animations and will be delivered to replace some of the usual RSE for the target age group in schools in the intervention group. Schools in the control group will not receive the intervention and will continue with usual RSE. Participants will not be blinded to allocation. Schools are the unit of randomisation stratified per country and socioeconomic status. We aim to recruit 66 UK schools (24 in Northern Ireland; 14 in each of England, Scotland and Wales), including approximately 7900 pupils. A questionnaire will be administered at baseline and at 12-14 months postintervention. The primary outcome is reported unprotected sex, a surrogate measure associated with unintended teenage pregnancy. Secondary outcomes include knowledge, attitudes, skills and intentions relating to avoiding teenage pregnancy in addition to frequency of engagement in sexual intercourse, contraception use and diagnosis of sexually transmitted infections. ETHICS AND DISSEMINATION: Ethical approval was obtained from Queen's University Belfast. Results will be published in peer-reviewed journals and disseminated to stakeholders. Funding is from the National Institute for Health Research. TRIAL REGISTRATION NUMBER: ISRCTN99459996.


Subject(s)
Adolescent Behavior/psychology , Clinical Trials, Phase III as Topic , Multicenter Studies as Topic , Pregnancy in Adolescence/prevention & control , Randomized Controlled Trials as Topic , School Health Services , Sex Education , Sexually Transmitted Diseases/prevention & control , Adolescent , Cluster Analysis , Contraception , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Peer Group , Pregnancy , Pregnancy in Adolescence/psychology , Sexual Behavior , Sexually Transmitted Diseases/psychology , United Kingdom/epidemiology
3.
Birth Defects Res A Clin Mol Teratol ; 100(9): 695-702, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25066220

ABSTRACT

BACKGROUND: Hirschsprung's disease is a congenital gut motility disorder, characterised by the absence of the enteric ganglion cells along the distal gut. The aim of this study was to describe the epidemiology of Hirschsprung's disease, including additional congenital anomalies, total prevalence, trends, and association with maternal age. METHODS: Cases of Hirschsprung's disease delivered during 1980 to 2009 notified to 31 European Surveillance of Congenital Anomaly registers formed the population-based case-series. Prevalence rates and 95% confidence intervals were calculated as the number of cases per 10,000 births. Multilevel Poisson regression was performed to investigate trends in prevalence, geographical variation and the association with maternal age. RESULTS: There were 1,322 cases of Hirschsprung's disease among 12,146,210 births. The total prevalence was 1.09 (95% confidence interval, 1.03-1.15) per 10,000 births and there was a small but significant increase in prevalence over time (relative risk = 1.01; 95% credible interval, 1.00-1.02; p = 0.004). There was evidence of geographical heterogeneity in prevalence (p < 0.001). Excluding 146 (11.0%) cases with chromosomal anomalies or genetic syndromes, there were 1,176 cases (prevalence = 0.97; 95% confidence interval, 0.91-1.03 per 10,000 births), of which 137 (11.6%) had major structural anomalies. There was no evidence of a significant increased risk of Hirschsprung's disease in cases born to women aged ≥35 years compared with those aged 25 to 29 (relative risk = 1.09; 95% credible interval, 0.91-1.31; p = 0.355). CONCLUSION: This large population-based study found evidence of a small increasing trend in Hirschsprung's disease and differences in prevalence by geographic location. There was also no evidence of an association with maternal age.


Subject(s)
Chromosome Aberrations , Hirschsprung Disease/epidemiology , Hirschsprung Disease/genetics , Registries , Adult , Case-Control Studies , Europe/epidemiology , Female , Hirschsprung Disease/mortality , Hirschsprung Disease/pathology , Humans , Infant , Infant, Newborn , Male , Maternal Age , Prevalence , Survival Analysis
4.
Public Health Genomics ; 17(2): 115-23, 2014.
Article in English | MEDLINE | ID: mdl-24714026

ABSTRACT

Congenital anomalies (CA) are the paradigm example of rare diseases liable to primary prevention actions due to the multifactorial etiology of many of them, involving a number of environmental factors together with genetic predispositions. Yet despite the preventive potential, lack of attention to an integrated preventive strategy has led to the prevalence of CA remaining relatively stable in recent decades. The 2 European projects, EUROCAT and EUROPLAN, have joined efforts to provide the first science-based and comprehensive set of recommendations for the primary prevention of CA in the European Union. The resulting EUROCAT-EUROPLAN 'Recommendations on Policies to Be Considered for the Primary Prevention of Congenital Anomalies in National Plans and Strategies on Rare Diseases' were issued in 2012 and endorsed by EUCERD (European Union Committee of Experts on Rare Diseases) in 2013. The recommendations exploit interdisciplinary expertise encompassing drugs, diet, lifestyles, maternal health status, and the environment. The recommendations include evidence-based actions aimed at reducing risk factors and at increasing protective factors and behaviors at both individual and population level. Moreover, consideration is given to topics specifically related to CA (e.g. folate status, teratogens) as well as of broad public health impact (e.g. obesity, smoking) which call for specific attention to their relevance in the pre- and periconceptional period. The recommendations, reported entirely in this paper, are a comprehensive tool to implement primary prevention into national policies on rare diseases in Europe.


Subject(s)
Congenital Abnormalities/prevention & control , Health Policy , Primary Prevention/methods , Rare Diseases , Congenital Abnormalities/epidemiology , Congenital Abnormalities/etiology , Congenital Abnormalities/genetics , Diet , Environmental Pollution/prevention & control , Europe/epidemiology , European Union , Evidence-Based Practice , Female , Folic Acid , Humans , Life Style , Male , Nutritional Physiological Phenomena , Obesity/complications , Obesity/prevention & control , Practice Guidelines as Topic , Preconception Care , Pregnancy , Risk Factors , Risk Management , Teratogens
5.
J Control Release ; 162(3): 529-37, 2012 Sep 28.
Article in English | MEDLINE | ID: mdl-22960496

ABSTRACT

Dissolving polymeric microneedle arrays formulated to contain recombinant CN54 HIVgp140 and the TLR4 agonist adjuvant MPLA were assessed for their ability to elicit antigen-specific immunity. Using this novel microneedle system we successfully primed antigen-specific responses that were further boosted by an intranasal mucosal inoculation to elicit significant antigen-specific immunity. This prime-boost modality generated similar serum and mucosal gp140-specific IgG levels to the adjuvanted and systemic subcutaneous inoculations. While the microneedle primed groups demonstrated a balanced Th1/Th2 profile, strong Th2 polarization was observed in the subcutaneous inoculation group, likely due to the high level of IL-5 secretion from cells in this group. Significantly, the animals that received a microneedle prime and intranasal boost regimen elicited a high level IgA response in both the serum and mucosa, which was greatly enhanced over the subcutaneous group. The splenocytes from this inoculation group secreted moderate levels of IL-5 and IL-10 as well as high amounts of IL-2, cytokines known to act in synergy to induce IgA. This work opens up the possibility for microneedle-based HIV vaccination strategies that, once fully developed, will greatly reduce risk for vaccinators and patients, with those in the developing world set to benefit most.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Lipid A/analogs & derivatives , Microinjections , env Gene Products, Human Immunodeficiency Virus/administration & dosage , AIDS Vaccines , Administration, Cutaneous , Animals , Cytokines/immunology , Female , HIV-1 , Immunoglobulin A/blood , Immunoglobulin A/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Lipid A/administration & dosage , Mice , Mice, Inbred BALB C , Needles , Recombinant Proteins/administration & dosage , Spleen/cytology , Spleen/immunology , Toll-Like Receptor 4/agonists , Vagina/immunology , env Gene Products, Human Immunodeficiency Virus/immunology
6.
Int J Pharm ; 430(1-2): 89-97, 2012 Jul 01.
Article in English | MEDLINE | ID: mdl-22486955

ABSTRACT

A major goal in vaccine development is elimination of the 'cold chain', the transport and storage system for maintenance and distribution of the vaccine product. This is particularly pertinent to liquid formulation of vaccines. We have previously described the rod-insert vaginal ring (RiR) device, comprising an elastomeric body into which are inserted lyophilised, rod-shaped, solid drug dosage forms, and having potential for sustained mucosal delivery of biomacromolecules, such as HIV envelope protein-based vaccine candidates. Given the solid, lyophilised nature of these insert dosage forms, we hypothesised that antigen stability may be significantly increased compared with more conventional solubilised vaginal gel format. In this study, we prepared and tested vaginal ring devices fitted with lyophilised rod inserts containing the model antigen bovine serum albumin (BSA). Both the RiRs and the gels that were freeze-dried to prepare the inserts were evaluated for BSA stability using PAGE, turbidimetry, microbial load, MALDI-TOF and qualitative precipitate solubility measurements. When stored at 4 °C, but not when stored at 40 °C/75% RH, the RiR formulation offered protection against structural and conformational changes to BSA. The insert also retained matrix integrity and release characteristics. The results demonstrate that lypophilised gels can provide relative protection against degradation at lower temperatures compared to semi-solid gels. The major mechanism of degradation at 40 °C/75% RH was shown to be protein aggregation. Finally, in a preliminary study, we found that addition of trehalose to the formulation significantly reduces the rate of BSA degradation compared to the original formulation when stored at 40 °C/75% RH. Establishing the mechanism of degradation, and finding that degradation is decelerated in the presence of trehalose, will help inform further development of RiRs specifically and polymer based freeze-dried systems in general.


Subject(s)
Drug Delivery Systems/instrumentation , Serum Albumin, Bovine/chemistry , Vaccines/chemistry , Administration, Intravaginal , Chemistry, Pharmaceutical , Chromatography, High Pressure Liquid , Circular Dichroism , Delayed-Action Preparations , Drug Carriers , Drug Compounding , Drug Stability , Elastomers/chemistry , Electrophoresis, Polyacrylamide Gel , Equipment Contamination , Equipment Design , Excipients/chemistry , Female , Freeze Drying , Gels , Humans , Humidity , Hypromellose Derivatives , Methylcellulose/analogs & derivatives , Methylcellulose/chemistry , Nephelometry and Turbidimetry , Polysorbates/chemistry , Protein Conformation , Protein Stability , Serum Albumin, Bovine/administration & dosage , Solubility , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Technology, Pharmaceutical/methods , Temperature , Thermogravimetry , Time Factors , Trehalose/chemistry , Vaccines/administration & dosage
7.
Eur J Pharm Sci ; 46(5): 315-22, 2012 Aug 15.
Article in English | MEDLINE | ID: mdl-22360941

ABSTRACT

Mucosally-administered vaccine strategies are widely investigated as a promising means of preventing HIV infection. This study describes the development of liposomal gel formulations, and novel lyophilised variants, comprising HIV-1 envelope glycoprotein, CN54gp140, encapsulated within neutral, positively charged or negatively charged liposomes. The CN54gp140 liposomes were evaluated for mean vesicle diameter, polydispersity, morphology, zeta potential and antigen encapsulation efficiency before being incorporated into hydroxyethyl cellulose (HEC) aqueous gel and subsequently lyophilised to produce a rod-shaped solid dosage form for practical vaginal application. The lyophilised liposome-HEC rods were evaluated for moisture content and redispersibility in simulated vaginal fluid. Since these rods are designed to revert to gel form following intravaginal application, mucoadhesive, mechanical (compressibility and hardness) and rheological properties of the reformed gels were evaluated. The liposomes exhibited good encapsulation efficiency and the gels demonstrated suitable mucoadhesive strength. The freeze-dried liposome-HEC formulations represent a novel formulation strategy that could offer potential as stable and practical dosage form.


Subject(s)
AIDS Vaccines/chemistry , Lipids/chemistry , env Gene Products, Human Immunodeficiency Virus/chemistry , AIDS Vaccines/administration & dosage , AIDS Vaccines/immunology , Adhesiveness , Administration, Intravaginal , Animals , Cellulose/analogs & derivatives , Cellulose/chemistry , Chemistry, Pharmaceutical , Compressive Strength , Drug Compounding , Female , Freeze Drying , Gels , Hardness , Liposomes , Mice , Mucins/metabolism , Recombinant Proteins/chemistry , Rheology , Surface Properties , Technology, Pharmaceutical/methods , Vaccines, Synthetic/chemistry , env Gene Products, Human Immunodeficiency Virus/administration & dosage , env Gene Products, Human Immunodeficiency Virus/immunology
8.
Vaccine ; 30(17): 2778-85, 2012 Apr 05.
Article in English | MEDLINE | ID: mdl-22361120

ABSTRACT

A robust vaginal immune response is considered essential for an effective prophylactic vaccine that prevents transmission of HIV and other sexually acquired diseases. Considerable attention has recently focused on the potential of vaginally administered vaccines as a means to induce such local immunity. However, the potential for vaccination at this site remains in doubt as the vaginal mucosa is generally considered to have low immune inductive potential. In the current study, we explored for the first time the use of a quick release, freeze-dried, solid dosage system for practical vaginal administration of a protein antigen. These solid dosage forms overcome the common problem associated with leakage and poor retention of vaginally administered antigen solutions. Mice were immunized vaginally with H4A, an HIV gp41 envelope based recombinant protein, using quick release, freeze-dried solid rods, and the immune responses compared to a control group immunized via subcutaneous H4A injection. Vaginally immunized mice failed to elicit robust immune responses. Our detailed investigations, involving cytokine analysis, the stability of H4A in mouse cervicovaginal lavage, and elucidation of the state of H4A protein in the immediate-release dosage form, revealed that antigen instability in vaginal fluid, the state of the antigen in the dosage form, and the cytokine profile induced are all likely to have contributed to the observed lack of immunogenicity. These are important factors affecting vaginal immunization and provide a rational basis for explaining the typically poor and variable elicitation of immunity at this site, despite the presence of immune responsive cells within the vaginal mucosae. In future mucosal vaccine studies, a more explicit focus on antigen stability in the dosage form and the immune potential of available antigen-responsive cells is recommended.


Subject(s)
AIDS Vaccines/administration & dosage , HIV Envelope Protein gp41/immunology , HIV-1/immunology , Vagina/immunology , AIDS Vaccines/immunology , Administration, Intravaginal , Animals , Antibody Specificity/immunology , Cytokines/metabolism , Female , HIV Antibodies/immunology , HIV Infections/immunology , HIV Infections/prevention & control , Humans , Immunoglobulin A/immunology , Interleukin-2/metabolism , Mice , Mice, Inbred BALB C , Mucous Membrane/immunology , Spleen/immunology , Spleen/metabolism , Th2 Cells/immunology
9.
AIDS Res Hum Retroviruses ; 28(7): 641-8, 2012 Jul.
Article in English | MEDLINE | ID: mdl-21861777

ABSTRACT

Well-defined correlates of protective immunity are an essential component of rational vaccine development. Despite years of basic science and three HIV vaccine efficacy trials, correlates of immunological protection from HIV infection remain undefined. In December 2010, a meeting of scientists engaged in basic and translational work toward developing HIV-1 vaccines was convened. The goal of this meeting was to discuss current opportunities and optimal approaches for defining correlates of protection, both for ongoing and future HIV-1 vaccine candidates; specific efforts were made to engage young scientists. We discuss here the highlights from the meeting regarding the progress made and the way forward for a protective HIV-1 vaccine.


Subject(s)
AIDS Vaccines , HIV Seropositivity/immunology , HIV-1/immunology , Immunologic Memory , T-Lymphocytes/immunology , Vaccines, Synthetic , AIDS Vaccines/immunology , Female , Genetic Vectors , HIV Seropositivity/drug therapy , HIV-1/drug effects , Humans , Immunity, Cellular/drug effects , Immunity, Mucosal/drug effects , Male , T-Lymphocytes/drug effects , Vaccines, Synthetic/immunology
10.
Vaccine ; 29(27): 4512-20, 2011 Jun 15.
Article in English | MEDLINE | ID: mdl-21514349

ABSTRACT

Vaccine-mediated prevention of primary HIV-1 infection at the heterosexual mucosal portal of entry may be facilitated by highly optimised formulations or drug delivery devices for intravaginal (i.vag) immunization. Previously we described hydroxyethylcellulose (HEC)-based rheologically structured gel vehicles (RSVs) for vaginal immunization of an HIV-1 vaccine candidate, a soluble recombinant trimeric HIV-1 clade-C envelope glycoprotein designated CN54gp140. Here we investigated the efficacy of lyophilized solid dosage formulations (LSDFs) for prolonging antigen stability and as i.vag delivery modalities. LSDFs were designed and developed that upon i.vag administration they would reconstitute with the imbibing of vaginal fluid to mucoadhesive, site-retentive semi-solids. Mice were immunized with lyophilized equivalents of (i) RSVs, (ii) modified versions of the RSVs more suited to lyophilization (sodium carboxymethyl cellulose (NaCMC)-based gels) and (iii) Carbopol(®) gel, all containing CN54gp140. NaCMC-based LSDFs provided significantly enhanced antigen stability compared to aqueous-based RSVs. Rheological analysis indicated the NaCMC-based LSDFs would offer enhanced vaginal retention in woman compared to more conventional vaginal gel formulations. All LSDFs were well tolerated in the mouse model. Following i.vag administration, all LSDFs boosted systemic CN54gp140-specific antibody responses in sub-cutaneously primed mice. Induction of CN54gp140-specific antibody responses in the female genital tract was evident. Of all the LSDFs the fastest releasing which was lyophilized Carbopol(®) gel elicited immune responses comparable to buffer instillation of antigen suggesting that rather than slower sustained release, initial high burst release from the LSDFs may suffice. The boosting of specific immune responses upon i.vag administration indicates that LSDFs are viable mucosal vaccine delivery modalities promoting antigen stability and facilitating intimate exposure of CN54gp140 to the mucosal-associated lymphoid tissue of the female genital tract.


Subject(s)
AIDS Vaccines/administration & dosage , HIV Antibodies/blood , HIV Infections/prevention & control , Immunity, Mucosal , Vaccines, Synthetic/administration & dosage , env Gene Products, Human Immunodeficiency Virus/administration & dosage , AIDS Vaccines/genetics , AIDS Vaccines/immunology , Acrylic Resins , Administration, Intravaginal , Animals , Chemistry, Pharmaceutical , Female , Freeze Drying , Gels/administration & dosage , Gels/chemistry , HIV Antibodies/immunology , HIV Infections/immunology , HIV-1/immunology , Humans , Immunization , Mice , Polyvinyls/chemistry , Rheology , Starch/analogs & derivatives , Starch/chemistry , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , env Gene Products, Human Immunodeficiency Virus/chemistry , env Gene Products, Human Immunodeficiency Virus/genetics , env Gene Products, Human Immunodeficiency Virus/immunology
11.
Eur J Pharm Biopharm ; 77(1): 3-10, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21055465

ABSTRACT

A new vaginal ring technology, the insert vaginal ring (InVR), is presented. The InVR overcomes the current shortfall of conventional vaginal rings (VRs) that are generally ineffectual for the delivery of hydrophilic and/or macromolecular actives, including peptides, proteins and antibodies, due to their poor permeation characteristics in the hydrophobic polymeric elastomers from which VRs are usually fabricated. Release of the model protein BSA from a variety of insert matrices for the InVR is demonstrated, including modified silicone rods, directly compressed tablets and lyophilised gels, which collectively provided controlled release profiles from several hours to beyond 4 weeks. Furthermore, the InVR was shown to deliver over 1 mg of the monoclonal antibody 2F5 from a single device, offering a potential means of protecting women against the transmission of HIV.


Subject(s)
Contraceptive Devices, Female , Delayed-Action Preparations , Proteins/administration & dosage , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/chemistry , Excipients/chemistry , Proteins/analysis , Proteins/chemistry , Silanes/chemistry , Silicone Elastomers/chemistry , Solubility , Technology, Pharmaceutical , Time Factors , Water/analysis
14.
Vaccine ; 27(48): 6791-8, 2009 Nov 12.
Article in English | MEDLINE | ID: mdl-19747994

ABSTRACT

Rheologically structured vehicle (RSV) gels were developed as delivery systems for vaginal mucosal vaccination with an HIV-1 envelope glycoprotein (CN54gp140). RSVs comprised a mucoadhesive matrix-forming and vaginal fluid absorbing polymer. The mucoadhesive and rheological properties of the RSVs were evaluated in vitro, and the distribution, antigenicity and release of CN54gp140 were analysed by ELISA. CN54gp140 was uniformly distributed within the RSVs and continuously released in vitro in an antigenically intact form over 24h. Vaginal administration to rabbits induced specific serum IgG, and IgG and IgA in genital tract secretions. The RSVs are a viable delivery modality for vaginal immunization.


Subject(s)
AIDS Vaccines/administration & dosage , AIDS Vaccines/immunology , HIV Antibodies/blood , env Gene Products, Human Immunodeficiency Virus/immunology , Administration, Intravaginal , Animals , Antibody Formation , Enzyme-Linked Immunosorbent Assay , Female , Gels , Immunity, Mucosal , Immunoglobulin A, Secretory/immunology , Immunoglobulin G/blood , Rabbits , Rheology
15.
Biomacromolecules ; 10(9): 2427-35, 2009 Sep 14.
Article in English | MEDLINE | ID: mdl-19642670

ABSTRACT

This investigation describes the formulation and characterization of rheologically structured vehicles (RSVs) designed for improved drug delivery to the vagina. Interactive, multicomponent, polymeric platforms were manufactured containing hydroxyethylcellulose (HEC, 5% w/w) polyvinylpyrrolidone (PVP, 4% w/w), Pluronic (PL, 0 or 10% w/w), and either polycarbophil (PC, 3% w/w) or poly(methylvinylether-co-maleic anhydride) (Gantrez S97, 3% w/w) as a mucoadhesive agent. The rheological (torsional and dynamic), mechanical (compressional), and mucoadhesive properties were characterized and shown to be dependent upon the mucoadhesive agent used and the inclusion/exclusion of PL. The dynamic rheological properties of the gel platforms were also assessed following dilution with simulated vaginal fluid (to mimic in vivo dilution). RSVs containing PC were more rheologically structured than comparator formulations containing GAN. This trend was also reflected in formulation hardness, compressibility, consistency, and syringeability. Moreover, formulations containing PL (10% w/w) were more rheologically structured than formulations devoid of PL. Dilution with simulated vaginal fluids significantly decreased rheological structure, although RSVs still retained a highly elastic structure (G' > G'' and tan delta < 1). Furthermore, RSVs exhibited sustained drug release properties that were shown to be dependent upon their rheological structure. It is considered that these semisolid drug delivery systems may be useful as site-retentive platforms for the sustained delivery of therapeutic agents to the vagina.


Subject(s)
Drug Delivery Systems/methods , Gels/chemistry , Adhesiveness , Administration, Intravaginal , Delayed-Action Preparations , Mechanical Phenomena , Rheology
16.
Toxicon ; 54(4): 491-8, 2009 Sep 15.
Article in English | MEDLINE | ID: mdl-19481560

ABSTRACT

Okadaic acid (OA) and structurally related toxins dinophysistoxin-1 (DTX-1), and DTX-2, are lipophilic marine biotoxins. The current reference method for the analysis of these toxins is the mouse bioassay (MBA). This method is under increasing criticism both from an ethical point of view and because of its limited sensitivity and specificity. Alternative replacement methods must be rapid, robust, cost effective, specific and sensitive. Although published immuno-based detection techniques have good sensitivities, they are restricted in their use because of their inability to: (i) detect all of the OA toxins that contribute to contamination; and (ii) factor in the relative toxicities of each contaminant. Monoclonal antibodies (MAbs) were produced to OA and an automated biosensor screening assay developed and compared with ELISA techniques. The screening assay was designed to increase the probability of identifying a MAb capable of detecting all OA toxins. The result was the generation of a unique MAb which not only cross-reacted with both DTX-1 and DTX-2 but had a cross-reactivity profile in buffer that reflected exactly the intrinsic toxic potency of the OA group of toxins. Preliminary matrix studies reflected these results. This antibody is an excellent candidate for the development of a range of functional immunochemical-based detection assays for this group of toxins.


Subject(s)
Antibodies, Monoclonal/immunology , Marine Toxins/immunology , Okadaic Acid/immunology , Pyrans/immunology , Animals , Biosensing Techniques , Bivalvia/chemistry , Enzyme-Linked Immunosorbent Assay , Food Contamination/prevention & control , Marine Toxins/toxicity , Mice , Mice, Inbred BALB C , Okadaic Acid/toxicity , Pyrans/toxicity
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