RESUMEN
BACKGROUND: Accurate component positioning is the key for successful outcome after total hip arthroplasty (THA). Positioning acetabular and femoral components in a safe zone of 25°-50° on the basis of combined anteversion (CA) has shown to reduce instability and impingement. This safe zone was described for THAs performed through the posterior approach and has not been validated for other surgical approaches. METHODS: Seventy patients who underwent unilateral uncemented THA were included in the study; 35 patients-using posterior approach and the remaining 35-using trans-gluteal approach. All patients included had a stable and impingement-free THA at a mean follow-up of 39.2 ± 9.5 months. CT scan was performed to assess component positioning by calculating CA. The values were compared between the two groups to study possible differences. RESULTS: CA in the trans-gluteal group was significantly lower (32° ± 3.7° vs 38.4° ± 4.6°, P < .001) compared to posterior group. The difference in CA was due to the differences in acetabular anteversion, which was significantly low in the trans-gluteal group than the posterior group (22.1° ± 3.6° vs 27.8° ± 4.2°, P < .001). The mean femoral anteversion was similar in both groups. All trans-gluteal hips fell within the safe zone of 20°-40°, and all posterior hips fell within the safe zone of 25°-50°. CONCLUSION: A safe zone of 25°-50° is valid for THAs performed from the posterior approach but not universally applicable. For trans-gluteal approach, a safe zone of 20°-40° is better to provide a stable and impingement-free THA. CA varies with the surgical approach. THAs performed through the trans-gluteal approach can be stable and impingement-free with lesser CA compared to THAs performed through the posterior approach.
Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Acetábulo/diagnóstico por imagen , Acetábulo/cirugía , Fémur/diagnóstico por imagen , Fémur/cirugía , Articulación de la Cadera/diagnóstico por imagen , Articulación de la Cadera/cirugía , Humanos , Estudios Retrospectivos , Tomografía Computarizada por Rayos XRESUMEN
INTRODUCTION AND HYPOTHESIS: The objective of the study was to identify reasons why women declined participation in a pilot randomised controlled trial (RCT) comparing tension-free vaginal tape (TVT) under general anaesthetic (GA) with single incision sling (SIS) under local anaesthetic (LA). These data would inform the design of a larger trial to improve patient recruitment. METHODS: This was a qualitative interview study on women eligible to have a TVT for stress urinary incontinence in a tertiary referral hospital in the UK. Women were counselled in a standardised manner. They were informed that the short-term success rates were similar for both operations. Women who declined to take part in the RCT were interviewed using a topic guide. Themes and sub-themes on non-participation were identified by two independent observers using a constant comparison method. RESULTS: Twenty-three non-participants of the RCT were interviewed. Common themes for non-participation were a preference for TVT and request for GA. Sub-themes showed that the TVT was preferred due to its perceived better efficacy as well as a minimal benefit from a SIS and also an unwillingness to take unknown risks. GA was favoured due to fear of local awareness, past negative experiences and embarrassment. Additional tests and follow-up visits were not cited as a reason for non-participation. CONCLUSIONS: The study found that non-participants are not research averse in general but they had strong preferences about specific aspects of treatment. Risk propensity and personality may also influence this behaviour. The study also demonstrates how a qualitative pilot study may improve trial design.
Asunto(s)
Participación del Paciente/psicología , Ensayos Clínicos Controlados Aleatorios como Asunto , Cabestrillo Suburetral , Incontinencia Urinaria de Esfuerzo/cirugía , Adulto , Anciano , Anestesia General , Anestesia Local , Femenino , Humanos , Entrevistas como Asunto , Persona de Mediana Edad , Medición de Riesgo , Centros de Atención Terciaria , Reino UnidoRESUMEN
Bulkamid is a periurethral bulking agent used to treat stress urinary incontinence (SUI). Manufacturers describe it as nontoxic, nonbiodegradable and biocompatible. Periurethral abscesses are one of the known complications of bulking agents. We present the first reported case of periurethral abscess following Bulkamid injection. The woman had previously had a transobturator tape (TOT) and total vaginal mesh repair. At 6 weeks after injection of the bulking agent, she reported 100 % cure of her SUI. Transperineal ultrasound was used to diagnose and monitor an abscess that developed anterior and lateral to the urethra and separate from the TOT. Magnetic resonance imaging was helpful in delineating the extent of the abscess into the retropubic space but was not able to identify the urethra or the TOT. Surgical drainage of the abscess was performed vaginally, resulting in successful resolution of pain but recurrence of incontinence.
Asunto(s)
Absceso/inducido químicamente , Resinas Acrílicas/efectos adversos , Resinas Acrílicas/uso terapéutico , Hidrogeles/efectos adversos , Hidrogeles/uso terapéutico , Enfermedades Uretrales/inducido químicamente , Incontinencia Urinaria de Esfuerzo/tratamiento farmacológico , Absceso/patología , Absceso/cirugía , Resinas Acrílicas/administración & dosificación , Anciano , Drenaje/métodos , Femenino , Procedimientos Quirúrgicos Ginecológicos , Humanos , Hidrogeles/administración & dosificación , Inyecciones , Imagen por Resonancia Magnética , Recurrencia , Resultado del Tratamiento , Enfermedades Uretrales/patología , Enfermedades Uretrales/cirugía , Incontinencia Urinaria de Esfuerzo/epidemiologíaRESUMEN
BACKGROUND: In the setting of intra-articular distal radius fractures, the volar lunate facet (VLF) is the only articular segment that resists volar carpal subluxation. So, it is important to achieve a stable fixation of this key fragment. The VLF, when small (also called as volar marginal fragment, VMF) is located distal to the watershed line making fixation with the conventional volar locking plates difficult or impossible. METHODS: 18 patients with either an AO: 2R3B3 or a C3 fracture consisting of a VMF underwent surgical repair through a volar approach. The VMF was stabilised using a anatomical volar hook plate. Remaining fracture components were stabilised using 2.4/ 2.0 mm locked plates. Fracture healing, ability of the hook plate to maintain reduction of the VMF and complications were assessed during follow up. Functional outcome was evaluated using Mayo score and patient rated wrist evaluation questionnaires. RESULTS: All fractures united at follow up. Reduction of the VMF was maintained through healing with a stable radiocarpal and distal radioulnar joint. The mean flexion - extension wrist arc was 105° ± 10.2° The mean grip strength reached 74.6 ± 6% of the opposite side. The mean Mayo wrist score was 75 ± 5.3 and the mean patient rated wrist evaluation (PRWE) score was 15.2 ± 4.3 indicating recovery of wrist function. CONCLUSION: It is important to identify VMFs in intra-articular distal radius fractures. Anatomically designed volar hook plate achieves excellent low-profile stable fixation of this key fragment to allow early mobilisation without fearing loss of reduction and volar carpal subluxation.
Asunto(s)
Fracturas Intraarticulares , Fracturas del Radio , Placas Óseas , Fijación Interna de Fracturas , Curación de Fractura , Humanos , Fracturas Intraarticulares/diagnóstico por imagen , Fracturas Intraarticulares/cirugía , Fracturas del Radio/diagnóstico por imagen , Fracturas del Radio/cirugía , Rango del Movimiento Articular , Resultado del Tratamiento , Articulación de la MuñecaRESUMEN
A seven-year-old, 31 kg male neutered Labrador was investigated for signs of feminisation syndrome and prostatic disease four years after castration and removal of a testicular sertoli cell tumour (SCT). Investigations revealed an elevated serum oestradiol-17beta concentration, a pulmonary mass containing fluid high in oestradiol-17beta and cystic changes in the prostate gland. The pulmonary mass was surgically excised and histologically confirmed to be a SCT metastasis. To the authors' knowledge, this is the first reported case of a proven functional extranodal SCT metastasis and the first to be diagnosed by oestradiol-17beta measurement of intralesional fluid.
Asunto(s)
Enfermedades de los Perros/diagnóstico , Estradiol/análisis , Neoplasias Pulmonares/veterinaria , Tumor de Células de Sertoli/veterinaria , Neoplasias Testiculares/veterinaria , Animales , Criptorquidismo/veterinaria , Quistes/patología , Quistes/veterinaria , Enfermedades de los Perros/patología , Enfermedades de los Perros/terapia , Perros , Feminización/etiología , Feminización/veterinaria , Neoplasias Pulmonares/secundario , Neoplasias Pulmonares/cirugía , Masculino , Próstata/diagnóstico por imagen , Radioinmunoensayo/veterinaria , Tumor de Células de Sertoli/complicaciones , Tumor de Células de Sertoli/diagnóstico , Tumor de Células de Sertoli/secundario , Neoplasias Testiculares/complicaciones , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/patología , Resultado del Tratamiento , UltrasonografíaRESUMEN
Hypertension is one of the major causes of cardiovascular morbidity and mortality. Community based studies in the rural areas of Tamil Nadu on the prevalence of hypertension and its associated risk factors are scarce. A cross-sectional study was undertaken among a sample of 406 individuals (45-60 years) selected by the standard 30 cluster systematic random sampling technique to find out prevalence of hypertension and its associated risk factors in a rural area of Tamil Nadu. Chi-square test and multiple logistic regression were employed using SPSS package. The overall prevalence of hypertension was 33% and higher among sedentary type (41%). In bivariate analysis many of the independent variables correlated with hypertension, but in multivariate analysis, only body-mass index, family history and age remained significant.
Asunto(s)
Hipertensión/epidemiología , Femenino , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Población RuralRESUMEN
The objectives of this systematic review were to investigate the efficacy of amoxicillin/amoxicillin-clavulanic acid for reducing the risk of postoperative infection after third molar surgery and to evaluate the adverse outcomes in these patients, as well as in healthy volunteers. A systematic search of four databases was performed on May 26, 2017. Eleven studies qualified for the qualitative analysis and eight were found suitable for meta-analysis. The results suggest that both amoxicillin-clavulanic acid and amoxicillin significantly reduce the risk of infection after third molar extraction (overall relative risk (RR) 0.25, P<0.001). However, with the exclusion of randomized controlled trials with a split-mouth design (due to an inadequate crossover period after antibiotic treatment), only amoxicillin-clavulanic acid was found to be effective (RR 0.21, P<0.001). The risk of adverse effects was significantly higher in the amoxicillin-clavulanic acid group (RR=4.12, P=0.023) than in the amoxicillin group (RR 1.57, P=0.405). In conclusion, amoxicillin-clavulanic acid and amoxicillin may significantly reduce the risk of infection after third molar extraction. However, their use in third molar surgery should be viewed with caution, as recent clinical trials on healthy volunteers have shown evidence of the negative impact of amoxicillin use on bacterial diversity and antibiotic resistance.
Asunto(s)
Combinación Amoxicilina-Clavulanato de Potasio/uso terapéutico , Amoxicilina/uso terapéutico , Antibacterianos/uso terapéutico , Tercer Molar/cirugía , Infección de la Herida Quirúrgica/prevención & control , Extracción Dental , Diente Impactado/cirugía , Profilaxis Antibiótica , HumanosRESUMEN
Routine postoperative antibiotic prophylaxis is not recommended for third molar extractions. However, amoxicillin still continues to be used customarily in several clinical practices worldwide to prevent infections. A prospective cohort study was conducted in cohorts who underwent third molar extractions with (group EA, n = 20) or without (group E, n = 20) amoxicillin (250 mg three times daily for 5 days). Further, a control group without amoxicillin and extractions (group C, n = 17) was included. Salivary samples were collected at baseline, 1-, 2-, 3-, 4-weeks and 3 months to assess the bacterial shift and antibiotic resistance gene changes employing 16S rRNA gene sequencing (Illumina-Miseq) and quantitative polymerase chain reaction. A further 6-month follow-up was performed for groups E and EA. Seven operational taxonomic units reported a significant change from baseline to 3 months for group EA (adjusted p < 0.05). No significant change in relative abundance of bacteria and ß-lactamase resistance genes (TEM-1) was observed over 6 months for any group (adjusted p > 0.05). In conclusion, the salivary microbiome is resilient to an antibiotic challenge by a low-dose regimen of amoxicillin. Further studies evaluating the effect of routinely used higher dose regimens of amoxicillin on gram-negative bacteria and antibiotic resistance genes are warranted.
Asunto(s)
Amoxicilina/efectos adversos , Antibacterianos/efectos adversos , Profilaxis Antibiótica/efectos adversos , Microbiota/efectos de los fármacos , Infección de la Herida Quirúrgica/prevención & control , Extracción Dental/efectos adversos , Adulto , Amoxicilina/administración & dosificación , Antibacterianos/administración & dosificación , Profilaxis Antibiótica/métodos , Profilaxis Antibiótica/normas , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Femenino , Estudios de Seguimiento , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/genética , Bacterias Gramnegativas/aislamiento & purificación , Humanos , Masculino , Microbiota/genética , Diente Molar/cirugía , Proyectos Piloto , Estudios Prospectivos , ARN Ribosómico 16S/genética , Saliva/microbiología , Infección de la Herida Quirúrgica/etiología , Adulto Joven , Resistencia betalactámica/efectos de los fármacos , Resistencia betalactámica/genética , beta-Lactamasas/genéticaRESUMEN
Carbamazepine (CBZ) is used in the treatment of generalized tonic clonic and partial seizures. In seizure disorder the focal point of treatment is brain. At present no commercial parenteral formulation of CBZ is available. We developed o/w nanoemulsions of CBZ stabilized by 1-O-alkylglycerol/lecithin for intravenous administration and evaluated the brain targeting potential of these formulations. The nanoemulsions were characterized for globule size, zeta potential (ZP), CBZ content and in vivo tissue distribution in mice. The in vivo data revealed a significant uptake of CBZ in all tissues. Among the nanoemulsions, 1-O-decylglycerol stabilized system showed significantly higher tissue levels and availability of CBZ. Particularly for this system 2.37 times higher brain availability and a brain/serum concentration ratio of 3.0 at 30 min is an important finding. This indicates the brain targeting potential. A systematic formulation development of CBZ nanoemulsions employing 1-O-alkylglycerols might pave way to achieve selective brain delivery of this important antiepileptic drug.
Asunto(s)
Anticonvulsivantes/administración & dosificación , Carbamazepina/administración & dosificación , Emulsiones , Glicerol/análogos & derivados , Nanotecnología , Animales , Anticonvulsivantes/farmacocinética , Carbamazepina/farmacocinética , Cromatografía Líquida de Alta Presión , Glicerol/química , Infusiones Intravenosas , Masculino , Ratones , Distribución TisularRESUMEN
The use of peptide-based drugs is limited by their rapid degradability and toxicity at high concentration during their therapeutic application. These problems could be managed by the use of a peptide delivery agent for sustained release in the site of action. Collagen is one of the most proven biomaterials of good biocompatibility with an exceptional ligand encapsulating property. In this work, we have shown that pexiganan, an antimicrobial, 22-amino-acid peptide could be incorporated and delivered to the wound-healing site against bacterial strains Pseudomonas aeruginosa and Staphylococcus aureus. The release profiles of pexiganan collagen films with different collagen concentration were studied. The release of pexiganan from 2.5% w/w of collagen film showed a sustainable activity over 72 h with effective antimicrobial concentrations. Pexiganan-incorporated collagen (PIC)-treated groups were compared with open wound (OW)- and collagen film (CF)-treated rats. PIC-treated animals showed a diminishing level of bacterial growth as compared with OW- and CF-treated animals. The biochemical parameters such as hydroxyproline, protein, DNA, uronic acid, hexosamine, SOD, and catalase content in the granulation tissue of the healing wound revealed increased proliferation of cells involved in tissue reconstruction in PIC-treated groups when compared with OW- and CF-treated groups. Furthermore, spectroscopic studies suggested that collagen structure is not perturbed by pexiganan incorporation. This study provides rationale for application of collagen membrane for antimicrobial peptide delivery in infected wounds.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/metabolismo , Colágeno/metabolismo , Sistemas de Liberación de Medicamentos , Cicatrización de Heridas , Infección de Heridas , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/uso terapéutico , Materiales Biocompatibles/metabolismo , Dicroismo Circular , Ensayo de Materiales , Pruebas de Sensibilidad Microbiana , Estructura Secundaria de Proteína , Pseudomonas aeruginosa/efectos de los fármacos , Ratas , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos , Infección de Heridas/tratamiento farmacológicoRESUMEN
Matrikines are small peptide fragments of extracellular matrix proteins that display potent tissue repair activities. Difficulties in achieving sustained delivery of bioactive concentration of matrikines in the affected area limits their therapeutic use. The present study evaluates the effects biotinylated matrikine peptide (bio-glycyl-histidyl-lysine) incorporated collagen membrane for dermal wound healing processes in rats. Biotinylated peptide incorporated collagen matrix (PIC) showed better healing when compared to wounds treated with collagen matrix [CF (collagen film)] and without collagen [CR (control)]. Binding studies indicate that biotinylated GHK (Bio-GHK) binds effectively to the collagen matrix and red blood cell (RBC) membrane when compared with t-butyloxycarbonyl substituted GHK (Boc-GHK). Wound contraction, increased cell proliferation, and high expression of antioxidant enzymes in PIC treated group indicate enhanced wound healing activity when compared to CF and CR groups. Interestingly Bio-GHK incorporated collagen increases the copper concentration by ninefold at the wound site indicating the wound healing property of Bio-GHK can also be linked with both copper localization and matrikine activities. These results demonstrate the possibility of using Bio-GHK incorporated collagen film as a therapeutic agent in the wound healing process.
Asunto(s)
Colágeno/química , Oligopéptidos/farmacología , Piel/patología , Cicatrización de Heridas/fisiología , Animales , Materiales Biocompatibles , Biotinilación , Cobre/análisis , Cobre/farmacología , Espectroscopía de Resonancia por Spin del Electrón , Masculino , Ensayo de Materiales , Modelos Moleculares , Ratas , Ratas Wistar , Termodinámica , Cicatrización de Heridas/efectos de los fármacosRESUMEN
We have been developing antioxidants incorporated collagen matrix as a novel biomaterial for various biomedical applications. In this study we made use of quercetin incorporated collagenous matrix for dermal wound healing in rat. Quercetin incorporated collagen (QIC) treated groups were compared with control and collagen (CS) treated animals. QIC treated animal showed a better healing when compared to control and CS treated wound. The biochemical parameters like hydroxyproline, protein, uronic acid content in the healing wound, revealed that there is an increase in proliferation of cells in quercetin treated groups when compared to CS group and there is considerable increase in wound contraction when compared to CS treated group. In addition we adapted the antioxidant assay using 2,2'-azobisisobutryonitrile (AIBN) to assess in vitro antioxidant activity of QIC. The antioxidant studies indicate QIC quench the radicals more efficiently. These results suggested that quercetin incorporated collagen matrix could be a novel dressing material for dermal wound healing.
Asunto(s)
Colágeno/uso terapéutico , Quercetina/química , Quercetina/farmacología , Piel/lesiones , Cicatrización de Heridas/efectos de los fármacos , Heridas Penetrantes/tratamiento farmacológico , Animales , Materiales Biocompatibles/síntesis química , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Colágeno/química , Masculino , Ensayo de Materiales , Ratas , Ratas Wistar , Piel/efectos de los fármacosRESUMEN
The wound healing process involves extensive oxidative stress to the system, which generally inhibits tissue remodeling. In the present study, an improvement in the quality of wound healing was attempted by slow delivery of antioxidants like curcumin from collagen, which also acts as a supportive matrix for the regenerative tissue. Curcumin incorporated collagen matrix (CICM) treated groups were compared with control and collagen treated rats. Biochemical parameters and histological analysis revealed that increased wound reduction, enhanced cell proliferation and efficient free radical scavenging in CICM group. The higher shrinkage temperature of CICM films suggests increased hydrothermal stability when compared to normal collagen films. Spectroscopic studies revealed that curcumin was bound to the collagen without affecting its triple helicity. Further we adopted the antioxidant assay using 2,2'-azobisisobutyronitrile to assess in vitro antioxidant activity of CICM. The antioxidant studies indicated that CICM quenches free radicals more efficiently. This study provides a rationale for the topical application of CICM as a feasible and productive approach to support dermal wound healing.
Asunto(s)
Colágeno/química , Curcumina/administración & dosificación , Curcumina/química , Cicatrización de Heridas/efectos de los fármacos , Heridas Penetrantes/tratamiento farmacológico , Heridas Penetrantes/patología , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Materiales Biocompatibles/administración & dosificación , Materiales Biocompatibles/química , División Celular , Colágeno/uso terapéutico , Preparaciones de Acción Retardada/administración & dosificación , Sistemas de Liberación de Medicamentos , Estabilidad de Medicamentos , Inhibidores Enzimáticos/administración & dosificación , Estudios de Factibilidad , Peroxidación de Lípido , Masculino , Ensayo de Materiales , Membranas Artificiales , Conformación Molecular , Ratas , Ratas Wistar , Piel/efectos de los fármacos , Piel/lesiones , Piel/patología , Resultado del TratamientoRESUMEN
A semianalytical technique to study the charged-particle transport in one-dimensional finite media is developed. For this purpose, the transport equation is written in the form of coupled integral equations, separating the spatial and energy-angle transmissions. Legendre polynomial representation for the source, flux, and scattering kernel are used to solve the equations. For evaluation of the spatial transmission, discrete ordinate representation in space, energy, and direction cosine is used for the particle and source flux. The integral equations are then solved by the fast iteration technique. The computer code CHASFIT, written on the basis of the above formulation, is described. The fast convergence of the iteration process which is characteristic of charged-particle transport is demonstrated. Convergence studies are carried out with a number of mesh points and polynomial approximations. The method is applied to study the depth-dose distributions due to 140-, 200-, 300-, 400-, 600-, and 740-MeV protons incident normally on a 30-cm-thick tissue slab. The values of the quality factor at the surface and at 5 cm depth, as well as the total average quality factor, are calculated. The results thus obtained are compared with those predicted by the Monte Carlo method. This method can also be applied to multienergy, multiregion systems with arbitrary degree of anisotropy.
Asunto(s)
Protones , Dosis de Radiación , Matemática , Modelos Teóricos , Método de MontecarloRESUMEN
Vesicles with biological activity or with a targeting function in addition to carrier properties will have an added advantage. Vesicles prepared with amphiphiles having antioxidant property may have potential applications towards disorders implicated with reactive oxygen species. Ascorbyl palmitate (ASP) was explored as bilayer vesicle forming material. It formed vesicles (Aspasomes) in combination with cholesterol and a negatively charged lipid (dicetyl phosphate). Aspasomes were prepared by film hydration method followed by sonication in which aqueous azidothymidine (AZT) solution was encapsulated in aqueous regions of bilayer. Aspasomes were obtained with all compositions containing 18-72 mol% cholesterol. Differential scanning calorimetric data of aspasome dispersion and anhydrous mixtures of ascorbyl palmitate, cholesterol and dicetyl phosphate confirm the formation of bilayered vesicles with ascorbyl palmitate. Cholesterol content in aspasome did not exhibit any relation with vesicle size, zeta potential or percent entrapment. A substantial change in release rate of azidothymidine from aspasome was noticed on varying the proportion of cholesterol. Release rate and cholesterol content in Aspasomes did not exhibit any relation. A preparation with 45 mol% of cholesterol showed maximum retardation in release rate, than other compositions. The change in capture volume with time (latency) was studied for 8 h and with such a short duration study it was difficult to predict long term stability of these vesicles. But release experiments do indicate stability up to 18 h. Percent reducing activity of aspasome was estimated by measuring the absorbance of alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) at 517 nm after addition of test antioxidant samples. These studies revealed that the antioxidant potency of ascorbyl moiety is retained even after converting ascorbyl palmitate into vesicles (Aspasomes). The antioxidant potency of Aspasomes was assessed by measuring the protection offered by this preparation against quinolinic acid induced lipoperoxidation of whole human blood in vitro, where in the lipoperoxidation was monitored by measuring thiobarbituric acid reactive substances (TBARS) levels. Aspasome rendered much better antioxidant activity than ascorbic acid. Transdermal permeation of aspasomal AZT, ASP-AZT aqueous dispersion and AZT-solution across excised rat skin was investigated in vitro using Franz diffusion cell. Permeation of aspasomal AZT was much higher than the other two preparations. However, ASP-AZT aqueous dispersion has also enhanced permeation of AZT significantly over the AZT-solution, indicating skin permeation enhancing property of ascorbyl palmitate.
Asunto(s)
Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/química , Portadores de Fármacos/química , Animales , Antioxidantes/administración & dosificación , Antioxidantes/química , Antioxidantes/farmacocinética , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Colesterol/química , Estabilidad de Medicamentos , Técnicas In Vitro , Membrana Dobles de Lípidos/química , Peroxidación de Lípido , Organofosfatos/química , Tamaño de la Partícula , Ratas , Absorción Cutánea , Solubilidad , Zidovudina/administración & dosificación , Zidovudina/química , Zidovudina/farmacocinéticaRESUMEN
1-O-alkylglycerols (ALKG) have exhibited several biological activities and a prominent effect on blood-brain barrier permeability. They have markedly improved brain uptake of cancerostatic agents. Since ALKG are amphiphilic, we explored their tendency to assemble into bilayer vesicles, which can be applied as carriers for drugs. Vesicles (Algosomes) were formed by film hydration method using ALKG (tetra-, penta-, hexa-, hepta-, octa- or nona-decylglycerols) in combination with cholesterol (CHOL) and dicetyl phosphate (DCP) (1-O-alkylglycerol:CHOL:DCP in 45:45:10 molar ratio). On microscopic examination, the algosomes were found to be conspicuously spherical and the dispersion was a mixture of multi-lamellar and small-unilamellar vesicles. Phase transition temperatures of 1-O-hexadecylglycerol (HXDG) and CHOL mixtures were tested by differential scanning calorimetry (DSC). The changes in phase transition temperatures indicate the vesicle forming tendency of ALKG in presence of CHOL. Alkyl chain length dependent variations in vesicle size, zeta-potential (ZP) and capture volume (CV) could not be observed. Vesicles of 1-O-tetradecylglycerol (TTDG) showed improvement in CV with increase in CHOL content from 15 to 55 mol%. However the vesicle size decreased. On challenging algosomes with hypertonic salt solution [potassium iodide (KI) in water], vesicle size decreased and thus algosomes were found to be osmotically sensitive. Algosome dispersions on addition of higher concentrations of KI (40-100 mM) brought about increases in vesicle size and at concentrations 60 mM and above showed aggregation. All vesicular dispersions were stable for only a few days.
Asunto(s)
Glicerol/análogos & derivados , Glicerol/química , Transporte Biológico , Rastreo Diferencial de Calorimetría , Cromatografía Líquida de Alta Presión , Portadores de Fármacos , Estabilidad de Medicamentos , Ósmosis , Fotomicrografía , Factores de Tiempo , Zidovudina/químicaRESUMEN
This study evaluated the effects of noncovalently incorporated crystallin into the collagen matrix for dermal wound-healing processes in rats. Crystallin-incorporated collagen matrix (CIC) showed better healing when compared to wounds treated with collagen matrix (CS) and without collagen (CR). Biochemical parameters and histological analysis revealed that increased wound contraction enhanced cell proliferation and efficient radical scavenging in the CIC group. The higher shrinkage temperature of CIC films when compared to CS groups suggested increased hydrothermal stability for the former material. An in vitro release study of CIC has showed sustained and time-dependent release of crystallin from the collagen matrix. These results demonstrate the possibility of using crystallin as therapeutic protein in the wound-healing process.