RESUMO
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.
Assuntos
Fraturas Intra-Articulares , Fraturas do Rádio , Placas Ósseas , Fixação Interna de Fraturas , Consolidação da Fratura , Humanos , Fraturas Intra-Articulares/diagnóstico por imagem , Fraturas Intra-Articulares/cirurgia , Fraturas do Rádio/diagnóstico por imagem , Fraturas do Rádio/cirurgia , Amplitude de Movimento Articular , Resultado do Tratamento , Articulação do PunhoRESUMO
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.
Assuntos
Artroplastia de Quadril , Prótese de Quadril , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/cirurgia , Humanos , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
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.
Assuntos
Amoxicilina/efeitos adversos , Antibacterianos/efeitos adversos , Antibioticoprofilaxia/efeitos adversos , Microbiota/efeitos dos fármacos , Infecção da Ferida Cirúrgica/prevenção & controle , Extração Dentária/efeitos adversos , Adulto , Amoxicilina/administração & dosagem , Antibacterianos/administração & dosagem , Antibioticoprofilaxia/métodos , Antibioticoprofilaxia/normas , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/isolamento & purificação , Humanos , Masculino , Microbiota/genética , Dente Molar/cirurgia , Projetos Piloto , Estudos Prospectivos , RNA Ribossômico 16S/genética , Saliva/microbiologia , Infecção da Ferida Cirúrgica/etiologia , Adulto Jovem , Resistência beta-Lactâmica/efeitos dos fármacos , Resistência beta-Lactâmica/genética , beta-Lactamases/genéticaRESUMO
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.
Assuntos
Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Amoxicilina/uso terapêutico , Antibacterianos/uso terapêutico , Dente Serotino/cirurgia , Infecção da Ferida Cirúrgica/prevenção & controle , Extração Dentária , Dente Impactado/cirurgia , Antibioticoprofilaxia , HumanosRESUMO
The present study examines the use of CS/TPP nanoparticles for gene delivery in different tissues of shrimp through oral route. The viral gene of WSSV was used to construct DNA vaccines using pcDNA 3.1, a eukaryotic expression vector and the constructs were named as pVP28. The CS/TPP nanoparticles were synthesized by ionic gelation process and these particles were characterized. The structure and morphology of the nanoparticles were studied by field emission scanning electron microscopy (FE-SEM) and FTIR (Fourier Transform Infrared Spectra). The cytotoxicity of CS/TPP nanoparticles was evaluated by MTT assay using fish cell line. The expression of gene was confirmed by Immuno-dot blot, ELISA and RT-PCR analyses. The results indicate that DNA can be easily delivered into shrimp by feeding with CS/TPP nanoparticles.
Assuntos
Quitosana/administração & dosagem , Crustáceos/genética , Técnicas de Transferência de Genes , Nanopartículas/administração & dosagem , Polifosfatos/administração & dosagem , Vacinas de DNA/administração & dosagem , Vacinas Virais/administração & dosagem , Administração Oral , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quitosana/toxicidade , Peixes , Microscopia Eletrônica de Varredura , Nanopartículas/toxicidade , Nanopartículas/ultraestrutura , Polifosfatos/toxicidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vacinas de DNA/genética , Vacinas de DNA/toxicidade , Vacinas Virais/genética , Vacinas Virais/toxicidade , Vírus da Síndrome da Mancha Branca 1/genéticaRESUMO
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.
Assuntos
Participação do Paciente/psicologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Slings Suburetrais , Incontinência Urinária por Estresse/cirurgia , Adulto , Idoso , Anestesia Geral , Anestesia Local , Feminino , Humanos , Entrevistas como Assunto , Pessoa de Meia-Idade , Medição de Risco , Centros de Atenção Terciária , Reino UnidoRESUMO
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.
Assuntos
Abscesso/induzido quimicamente , Resinas Acrílicas/efeitos adversos , Resinas Acrílicas/uso terapêutico , Hidrogéis/efeitos adversos , Hidrogéis/uso terapêutico , Doenças Uretrais/induzido quimicamente , Incontinência Urinária por Estresse/tratamento farmacológico , Abscesso/patologia , Abscesso/cirurgia , Resinas Acrílicas/administração & dosagem , Idoso , Drenagem/métodos , Feminino , Procedimentos Cirúrgicos em Ginecologia , Humanos , Hidrogéis/administração & dosagem , Injeções , Imageamento por Ressonância Magnética , Recidiva , Resultado do Tratamento , Doenças Uretrais/patologia , Doenças Uretrais/cirurgia , Incontinência Urinária por Estresse/epidemiologiaRESUMO
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.
Assuntos
Hipertensão/epidemiologia , Feminino , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , População RuralRESUMO
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.
Assuntos
Doenças do Cão/diagnóstico , Estradiol/análise , Neoplasias Pulmonares/veterinária , Tumor de Células de Sertoli/veterinária , Neoplasias Testiculares/veterinária , Animais , Criptorquidismo/veterinária , Cistos/patologia , Cistos/veterinária , Doenças do Cão/patologia , Doenças do Cão/terapia , Cães , Feminização/etiologia , Feminização/veterinária , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Masculino , Próstata/diagnóstico por imagem , Radioimunoensaio/veterinária , Tumor de Células de Sertoli/complicações , Tumor de Células de Sertoli/diagnóstico , Tumor de Células de Sertoli/secundário , Neoplasias Testiculares/complicações , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/patologia , Resultado do Tratamento , UltrassonografiaRESUMO
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.
Assuntos
Anticonvulsivantes/administração & dosagem , Carbamazepina/administração & dosagem , Emulsões , Glicerol/análogos & derivados , Nanotecnologia , Animais , Anticonvulsivantes/farmacocinética , Carbamazepina/farmacocinética , Cromatografia Líquida de Alta Pressão , Glicerol/química , Infusões Intravenosas , Masculino , Camundongos , Distribuição TecidualRESUMO
Oral hepatitis B vaccine formulation was prepared by successful encapsulation of immunogenic peptide representing residues 127-145 of the immunodominant B-cell epitope of hepatitis B surface antigen (HBsAg) in poly(D,L-lactide co-glycolide) (PLG) microparticles. The smooth, spherical PLG microparticles with a diameter of around 10 microm was prepared by using W/O/W double emulsion solvent evaporation method. The entrapment efficiency of B-cell epitope peptide (BCEP) into PLG microparticles was 64%. In vitro studies showed B-cell epitope loaded PLG microparticles (BCEM) released the peptide in sustained profile and reached 64.9% efficiency by Day 25. Single oral immunization of mice with BCEM led to the significant induction of specific serum IgG and IgM anti-HB antibodies. After the termination of antibody induction, the orally immunized mice were infected with HBsAg, which resulted in the rapid production of antibodies against HBsAg as a result of secondary immune response. PLG microparticles formulation approach may have potential in increasing the efficacy of microparticulate systems for the oral administration of hepatitis B vaccine.
Assuntos
Epitopos de Linfócito B , Vacinas contra Hepatite B/administração & dosagem , Ácido Láctico/administração & dosagem , Ácido Poliglicólico/administração & dosagem , Polímeros/administração & dosagem , Administração Oral , Animais , Feminino , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , VacinaçãoRESUMO
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.
Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Colágeno/metabolismo , Sistemas de Liberação de Medicamentos , Cicatrização , Infecção dos Ferimentos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Materiais Biocompatíveis/metabolismo , Dicroísmo Circular , Teste de Materiais , Testes de Sensibilidade Microbiana , Estrutura Secundária de Proteína , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Infecção dos Ferimentos/tratamento farmacológicoRESUMO
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.
Assuntos
Colágeno/química , Oligopeptídeos/farmacologia , Pele/patologia , Cicatrização/fisiologia , Animais , Materiais Biocompatíveis , Biotinilação , Cobre/análise , Cobre/farmacologia , Espectroscopia de Ressonância de Spin Eletrônica , Masculino , Teste de Materiais , Modelos Moleculares , Ratos , Ratos Wistar , Termodinâmica , Cicatrização/efeitos dos fármacosRESUMO
Pexiganan (Gly-Ile-Gly-Lys-Phe-Leu-Lys-Lys-Ala-Lys-Lys-Phe-Gly-Lys-Ala-Phe-Val-Lys-Ile-Leu-Lys-Lys), a 22 amino acid peptide, is an analogue of the magainin family of antimicrobial peptides present in the skin of the African clawed frog. Conformational analysis of pexiganan was carried out in different solvent environments for the first time. Organic solvents, trifluoroethanol (TFE) and methanol, were used to study the secondary structural preferences of this peptide in the membrane-mimicking environments. In addition, aqueous (D2O) and dimethyl sulfoxide (DMSO) solutions were also investigated to study the role of hydrogen bonding involved in the secondary structure formation. Fourier transform infrared absorption, vibrational circular dichroism (VCD), and electronic circular dichroism (ECD) measurements were carried out under the same conditions to ascertain the conformational assignments in different solvents. All these spectroscopic measurements suggest that the pexiganan peptide has the tendency to adopt different structures in different environments. Pexiganan appears to adopt an alpha-helical conformation in TFE, a sheet-stabilized beta-turn structure in methanol, a random coil with beta-turn structure in D2O, and a solvated beta-turn structure in DMSO.
Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Dicroísmo Circular , Estrutura Secundária de Proteína , Soluções , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
A clinical descriptive study was conducted to assess the frequency and pattern of involvement of cranial nerves in leprosy and to study the relationship of cranial nerve involvement with a leprosy patch or patches on facial skin. One hundred consecutive patients of leprosy, diagnosed by clinical features and/or slit skin smear and histopathology, were studied; of these, 22 patients had cranial nerve involvement. The mean age of patients with cranial nerve involvement was 41.2 years. 16 patients (72.7%) with cranial nerve involvement were in the age-group of 20-49 years. The male-to-female ratio was 3.4:1. The mean duration of the disease in these patients was 5.73 years. The duration of the disease in the majority of patients with cranial nerve involvement was less than 5 years. Impairment of cranial nerves was seen in 12 BT patients, 6 BL patients, and 4 LL patients. No significant difference was noted between involvement of cranial nerves in PB and MB patients. Among the cranial nerves, facial nerve was the most common nerve involved (10/22), followed by olfactory (9/22), trigeminal (7/22) and auditory (3/22) nerves. Among the risk factors, it was found that facial nerve impairment was significantly associated with facial patch(es) and also type 1 lepra reaction.
Assuntos
Nervos Cranianos/fisiopatologia , Hanseníase/fisiopatologia , Adulto , Distribuição por Idade , Feminino , Humanos , Hanseníase/classificação , Masculino , Pessoa de Meia-Idade , Distribuição por Sexo , População UrbanaRESUMO
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.