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PubMed1990

Estimation of right ventricular pressure by 201Tl scintigraphy in paediatric cardiac disease.

To estimate right ventricular overload in paediatric cardiac disease, 201Tl scintigraphy was used to quantify right ventricular uptake. Six methods for calculating the 201Tl right-to-left ventricular uptake ratio (TRL) were compared, based on the location of regions of interest (ROIs), use of total count or mean count density, and the ROI-based method or profile method. When the TRL was compared with the right-to-left ventricular peak systolic pressure ratio (RVP/LVP), the mean count density method using entire right and left ventricular ROIs seemed to be appropriate, considering its simplicity, reproducibility and regression line. The linear regression line was RVP/LVP = 1.15 x TRL - 0.13 (n = 15, P = -0.0001), and RVP(mm Hg) = 162 x TRL - 33 (n = 15, P = 0.0001). In four patients with pulmonary stenosis, the changes of TRL were in good agreement with the right ventricular pressure changes after percutaneous balloon valvuloplasty. Thus, evaluation of thallium scintigraphy using this quantitative method can be a simple and effective way to evaluate patients with right ventricular pressure overloading.

Adolescent↗
PubMed1997

A limited sampling approach in bioequivalence studies.

A limited sampling model (LSM) has been developed for an antidepressant immediate-release product (Drug A) and an antiepileptic controlled release product (Drug B) to predict the area under the curve (AUC) and the maximum plasma concentration (Cmax) and to compare the bioequivalence of two formulations of each drug using predicted versus observed AUC and Cmax after a single oral dose. The LSM for drug A was developed using data from 10 healthy people. The correlation between plasma concentration (independent variable) at selected time points with the AUC or Cmax (dependent variable) was evaluated by simple regression analysis. The linear regression that gave the best correlation coefficient (r) for a single sampling time versus AUC or Cmax was chosen as the LSM. The model provided good estimates of AUC and Cmax for drug A. The 90% confidence interval on log transformed observed and predicted AUC and Cmax were as follows: AUC observed = 100% to 118%, AUC predicted = 101% to 117%, Cmax observed = 99% to 125%, and Cmax predicted = 100% to 131%. The LSM for drug B was developed using a similar approach to drug A. The 90% confidence interval on log transformed observed and predicted AUC and Cmax were: AUC observed = 99% to 110%, AUC predicted = 99% to 118%, Cmax observed = 107% to 120%, and Cmax predicted = 99% to 111%. Although the predicted Cmax did not meet the 90% confidence interval for drug A, the method described here may be used to estimate AUC and Cmax for a drug in bioequivalence studies without detailed blood sampling. More research is needed in this direction.

Anticonvulsants↗
PubMed1996

Evaluation of pulse oximetry in anaesthetised foals using multiple combinations of transducer type and transducer attachment site.

A commercially available pulse oximeter was evaluated in anaesthetised foals to determine its accuracy for estimating arterial haemoglobin saturation (SaO2). Five different transducer/transducer attachment site (TTAS) combinations were evaluated; 1-3) a fingertip transmission transducer attached to the foal's ear, lip and tongue, 4) an adhesive transmission transducer positioned on the foal's ear and 5) a forehead reflectance transducer placed on the ventral aspect of the foal's tail-base. Eight normal, Quarter Horse foals (age 5-10 days) were studied while under general anaesthesia. Alterations in arterial carbon dioxide tension (PaCO2) were produced by changing the level of ventilation. At each level of ventilation, alterations of arterial haemoglobin saturation (SaO2) were produced by varying the inspired fraction of oxygen (FIO2). At each level of ventilation and each level of FIO2, arterial blood samples were obtained for blood gas analysis while pulse oximeter readings were recorded simultaneously for each TTAS combination. Arterial blood oxygen saturation (SaO2) was calculated from arterial blood gas values and the equine blood oxygen dissociation curve. Pulse oximeter readings from each TTAS combination were compared with SaO2 values with linear regression analyses. Bias and precision values were determined and the sensitivity and specificity of each TTAS combination for detecting desaturation (SaO2 < 90%) were determined. Linear regression analyses indicated significant (P < 0.05) linear correlation between oxygen saturation determined by pulse oximeter (SpO2) and SaO2 for each of the 5 TTAS combinations. The combinations TTAS-1, TTAS-3 and TTAS-4 tended slightly to underestimate SaO2 at high SaO2 ranges, but overestimated SaO2 at low ranges of SaO2. Combination TTAS-2 overestimated SaO2 over all ranges of SaO2. Combination TTAS-5 consistently underestimated SaO2 at all ranges of SaO2. In general, accuracy and precision of each TTAS combination decreased at lower SaO2 ranges. All TTAS combinations, except TTAS-2 and TTAS-4, had good sensitivity for detecting SaO2 less than 90%. All TTAS combinations except TTAS-5 demonstrated good specificity. We concluded that pulse oximetry appears to be a valuable method for assessing SaO2 and detecting desaturation in anaesthetised foals. Clinicians should be aware that the type of transducer used and the anatomical site to which it is attached can have marked effects on the accuracy of pulse oximetry; and that different TTAS combinations may behave differently over various ranges of SaO2.

Anesthesia↗
PubMed1994

MIB-1, Ki67, and PCNA scores and DNA flow cytometry in intermediate grade malignant lymphomas.

AIMS: To verify the correlation between MIB-1, Ki67, and proliferating cell nuclear antigen (PCNA-PC10) scores and S-phase fraction in intermediate grade non-Hodgkin's lymphomas (Working Formulation F); and their reliability in differently processed tissues. METHODS: Forty one non-Hodgkin's lymphomas were classified as (F) intermediate grade malignant lymphomas according to the Working Formulation; mitotic counts and percentage of large cells were assessed for each case. Sections from formalin fixed, paraffin wax embedded tissues were stained with anti MIB-1 monoclonal antibody, after microwave oven processing, and anti-PCNA (PC10) monoclonal antibody using an avidin-biotin immunoperoxidase (ABC) method. One thousand cells from 10 representative fields were scored. Frozen sections from surgical specimens were stained with Ki67 monoclonal antibody using the ABC method; the fraction of Ki67 positive cells was calculated scoring 1000 cells. Flow cytometry analysis (FCM) was performed on cell suspensions from fresh tissues. Correlations between data were estimated using linear regression. RESULTS: A linear correlation was found between MIB-1 and Ki67 scores (r = 0.92; p < 0.00001); between MIB-1 and PCNA scores (r = 0.79; p < 0.00001); and between MIB-1 score and S-phase fraction (r = 0.51; p = 0.0006). A linear correlation was also found between Ki67 and PCNA scores (r = 0.85; p < 0.00001); between Ki67 score and S-phase fraction (r = 0.6; p = 0.0002); and between PCNA score and S-phase fraction (r = 0.74; p < 0.00001). A correlation was found between mitotic counts and MIB-1 (r = 0.56; p = 0.0001), PCNA (r = 0.51; p = 0.0007), or Ki67 scores (r = 0.47; p = 0.002); between the percentage of large cells and MIB-1 (r = 0.49; p = 0.0009), PCNA (r = 0.6; p = 0.00003), and Ki67 scores (r = 0.53; p = 0.0003) and S-phase fraction (r = 0.55; p = 0.0002). CONCLUSION: MIB-1, Ki67, and PCNA (PC10) scores and S-phase fraction are highly correlated and equally well represent the proliferative activity of intermediate grade non-Hodgkin's lymphomas in differently processed material. MIB-1 and PCNA stains can be applied even on small biopsy specimens. MIB-1 produces homogenous staining without background; it also strongly stains mitotic figures. It can be performed on routinely processed tissues, permitting the simultaneous evaluation of the morphology and tumour cell kinetics. The wide standard deviations of the proliferative indices found for intermediate grade NHL suggest that this category probably includes various degrees of malignancy.

Antibodies, Monoclonal↗
PubMed2006

Prediction of sickness absence: development of a screening instrument.

OBJECTIVES: To develop a concise screening instrument for early identification of employees at risk for sickness absence due to psychosocial health complaints. METHODS: Data from the Maastricht Cohort Study on "Fatigue at Work" were used to identify items to be associated with an increased risk of sickness absence. The analytical procedures univariate logistic regression, backward stepwise linear regression, and multiple logistic regression were successively applied. For both men and women, sum scores were calculated, and sensitivity and specificity rates of different cut-off points on the screening instrument were defined. RESULTS: In women, results suggested that feeling depressed, having a burnout, being tired, being less interested in work, experiencing obligatory change in working days, and living alone, were strong predictors of sickness absence due to psychosocial health complaints. In men, statistically significant predictors were having a history of sickness absence, compulsive thinking, being mentally fatigued, finding it hard to relax, lack of supervisor support, and having no hobbies. A potential cut-off point of 10 on the screening instrument resulted in a sensitivity score of 41.7% for women and 38.9% for men, and a specificity score of 91.3% for women and 90.6% for men. CONCLUSIONS: This study shows that it is possible to identify predictive factors for sickness absence and to develop an instrument for early identification of employees at risk for sickness absence. The results of this study increase the possibility for both employers and policymakers to implement interventions directed at the prevention of sickness absence.

Absenteeism↗
PubMed1995

Are the respiratory health effects found in manufacturers of ceramic fibres due to the dust rather than the exposure to fibres?

OBJECTIVES: To determine whether the respiratory symptoms and decrements in lung function found in manufacturers of ceramic fibres are related to exposure to the respirable fibre or inspirable mass constituents of the air in the working environment. METHODS: Cross sectional survey of all current European primary producers of ceramic fibre was carried out, with measurement of exposure to respiratory fibres by personal samplers that measured inspirable and total mass, together with a health survey with an expanded respiratory questionnaire and standardised measurement of lung function. Odds ratios were calculated for symptoms and current exposure by multiple logistic regression, and multiple linear regression coefficients for lung function related to cumulative exposures controlled for the effects of respirable fibre and inspirable mass separately and together. RESULTS: Significant effects of current exposure to both inspirable dust and respirable fibres were related to dry cough, stuffy nose, eye and skin irritation and breathlessness. The decrements found in smokers and to some extent in ex-smokers in forced expiratory volume in one second and forced expiratory flow from 25% to 75% of expiratory volume, seem to be related to the respirable fibres rather than the inspirable mass constituents of the environment. CONCLUSIONS: Current symptoms were related to both current exposure to inspirable dust and respirable fibre. The decrements in lung function were related to the fibre constituent of the exposure.

Air Pollutants, Occupational↗
PubMed1986

Mathematical coupling of data: correction of a common error for linear calculations.

The need frequently arises in the scientific environment to investigate the relationship between quantities that are calculated from a common set of directly measured variables. However, the presence of error in the common set of measured variables distorts the relationship among the calculated quantities and can lead to incorrect conclusions. This article presents a method of correcting for such distortions in the Pearson correlation coefficient and in the linear regression coefficient for linear calculations involving two measured variables. The errors considered may be either independent of, or proportional to, the value of the variable being measured. Tests to determine whether these popular coefficients have values significantly different from zero are presented. An example from the physiology literature is presented to illustrate these techniques.

Mathematics↗
PubMed1996

Vertebral bone mineral density in postpartum women.

The purpose of this study was to measure the bone mineral density of the lumbar spine (L2-L4) in healthy postpartum women following term delivery, and to evaluate factors associated with bone mineral density. Using dual energy X-ray absorptiometry, the bone mineral density of the lumbar spine was determined during 1 year in 123 healthy postpartum Japanese women following term delivery. The mean bone mineral density of the lumbar spine was 1.007 +/- 0.108 g/cm2 (range 0.731-1.252 g/cm2). Thus, there were wide inter-individual differences. Also, this result was in agreement with the peak bone mass previously reported for other Japanese women. Multiple regression analysis and linear regression analysis showed that weight and body mass index were each significantly correlated with bone mineral density of the lumbar spine. Age, parity, height, and baby's birth weight were not contributory.

Absorptiometry, Photon↗
PubMed2000

Brain tissue sodium is a ticking clock telling time after arterial occlusion in rat focal cerebral ischemia.

BACKGROUND AND PURPOSE: Many patients with acute stroke are excluded from receiving thrombolysis agents within the necessary time limit (3 or 6 hours from stroke onset) because they or their family members are unable provide the time of stroke onset. Brain tissue sodium concentration ([Na(+)]) increases gradually and incessantly during the initial hours of experimental focal cerebral ischemia but only in severely damaged brain regions. We propose that this steady increase in [Na(+)] can be used to estimate the time after arterial occlusion in the rat middle cerebral artery occlusion model of ischemic stroke. METHODS: Sixteen anesthetized Sprague-Dawley rats underwent permanent middle cerebral artery occlusion combined with bilateral common artery occlusion. After 100 to 450 minutes, diffusion-weighted MRI was used to generate apparent diffusion coefficient (ADC) maps, cerebral blood flow (CBF) was determined with (14)C-iodoantipyrine (in a subset of 7 animals), and the brain was frozen. Autoradiographic CBF sections and punch samples for Na(+) analysis were obtained from the brain at the same level of the MR image. Severely at risk regions were identified with an ADC of <520 microm(2)/s and, in the subset, with both ADC of <520 microm(2)/s and CBF of <40 mL. 100 g(-1). min(-1). RESULTS: Both CBF and the ADC dropped quickly and remained stable in the initial hours after ischemic onset. Linear regression revealed strong linearity between [Na(+)] and time after onset, with a slope of 0.95 or 1.00 (mEq/kg DW)/min, with both ADC and ADC-plus-CBF criteria, respectively. The 95% CIs at 180 and 360 minutes were between 41 and 52 minutes. CONCLUSIONS: The time after ischemic onset can be estimated with this 2-step process. First, ADC and CBF are used to identify severely endangered regions. Second, the [Na(+)] in these regions is used to estimate time after onset. The favorable 95% CIs at the time limits for thrombolytic therapy and the availability of measurements of ADC, CBF, and [Na(+)] in humans through the use of MRI suggest that this time-estimation scheme could be used to assess the appropriateness of thrombolysis for patients who do not know when the stroke occurred.

Animals↗
PubMed2005

Effect of water activity and temperature on growth and the relationship between fumonisin production and the radial growth of Fusarium verticillioides and Fusarium proliferatum on corn.

The two major fumonisin-producing Fusarium species are Fusarium verticillioides and Fusarium proliferatum. The growth and fumonisin production of these two isolates on corn was studied at water activities (a(w)) between 0.860 and 0.975 and at temperatures between 15 and 30 degrees C. Growth rates (g, mm/day) were obtained by linear regression during the linear phase of growth. In general, growth rates for both isolates increased significantly (P < 0.05) with increases in a(w) and temperature. Both fumonisin production and radial growth (mycelial development) for both isolates increased with a(w) at all temperatures investigated, but the effect of temperature on this relationship was not obvious. The effect of temperature on fumonisin production at high a(w) values optimal for growth was only marginal, whereas at lower a(w) values the effect of temperature was more pronounced, with more fumonisin production occurring at temperatures not optimal for growth. The optimum temperature for fumonisin production was between 15 and 25 degrees C. For F. proliferatum, the optimum temperature for growth at all a(w) values, 30 degrees C, resulted in the poorest fumonisin production. For both isolates, the slowest initial rate of fumonisin production was at 15 degrees C, the temperature at which the slowest growth rates were obtained.

Animals↗
PubMed1985

The use of the abdominal circumference as a means of assessing M-mode ventricular dimensions during the second and third trimesters of pregnancy in the normal human fetus.

Eighty-two normal fetuses were scanned from 18 to 41 weeks of gestation. The following M-mode measurements were correlated with the abdominal circumference: diastolic biventricular outer (r = 0.951) and inner (r = 0.948) dimensions; diastolic right (r = 0.942) and left (r = 0.925) internal dimensions; tricuspid (r = 0.916) and mitral (r = 0.900) valve opening excursions; and right (r = 0.774), left (r = 0.731), and interventricular septal (r = 0.753) wall thickness. Polynomial regression demonstrated that linear regression best described the data from which the mean and 5 per cent and 95 per cent confidence limits for predicted M-mode measurements were computed for the abdominal circumference between 12 and 35 cm.

Embryonic and Fetal Development↗
PubMed1999

Salivary antiepileptic drug levels in Thai children.

A total of 123 patients were enrolled in this study. 88 patients were enrolled in the first stage of the study, which was to evaluate the commercial salivary collecting devices: Orasure and Omnisol. 35 patients were enrolled in the second stage of the study and were asked to spit whole saliva samples for further analysis of AED levels. Serum AED levels and corresponding saliva AED levels were paired and analyzed for the correlation coefficients with the linear regression model. None of the commercial salivary collecting devices can provide the linear regression correlation between the serum AED level and saliva AED level in all three AEDs studied. The correlation coefficients of serum and whole saliva AED levels of phenobarbital, phenytoin, and carbamazepine were highly correlated (r-squared were 0.981, 0.976, and 0.888, respectively). Saliva samples can be used clinically to monitor the AEDs level in phenobarbital, phenytoin and carbamazepine. This would be another alternative method of therapeutic drug monitoring that can be done painlessly and is easier in children than the blood sampling method.

Anticonvulsants↗
PubMedDate not supplied

Rate of decline of residual renal function in patients on continuous peritoneal dialysis and factors affecting it.

OBJECTIVE: We analyzed residual renal function (RRF) in a large number of new peritoneal dialysis (PD) patients to prospectively define the time course of decline of RRF and to evaluate the risk factors assumed to be associated with faster decline. STUDY DESIGN: Single-center, prospective cohort study. SETTING: Home PD unit of a tertiary care University Hospital. PATIENTS: The study included 242 patients starting continuous PD between January 1994 and December 1997, with a minimum follow-up of 6 months and at least three measurements of RRF. MEASUREMENT: All patients had data on demographic and laboratory variables, episodes of peritonitis and the use of aminoglycoside (AG) antibiotics, temporary hemodialysis, and number of radiocontrast studies. Adequacy of PD was measured from 24-hour urine and dialysate collection and peritoneal equilibration test using standard methodology. Further data on RRF was collected every 3 to 4 months until the patient became anuric (urine volume < 100 mL/day or creatinine clearance < 1.0 mL/min) or until the end of study in December 1998. OUTCOME MEASURE: The slope of the decline of residual glomerular filtration rate (GFR) (an average of renal urea and creatinine clearance) was the main outcome measure. Risk factors associated with faster decline were evaluated by a comparative analysis between patients in the highest and the lowest quartiles of the slopes of GFR, and a multivariate analysis using a stepwise option within linear regression and general linear models. RESULTS: There was a gradual deterioration of residual GFR with time on PD, with 40% of patients developing anuria at a mean of 20 months after the initiation of PD. On multivariate analysis, use of a larger volume of dialysate (p = 0.0001), higher rate of peritonitis (p = 0.0005), higher use of AG (p = 0.0006), presence of diabetes mellitus (p = 0.005), larger body mass index (BMI) (p = 0.01), and no use of antihypertensive medications (p = 0.04) independently predicted the steep slope of residual GFR. Male gender, higher grades of left ventricular dysfunction, and higher 24-hour proteinuria were associated with faster decline on univariate analysis only. CONCLUSION: Faster decline of residual GFR corresponds with male gender, large BMI, presence of diabetes mellitus, higher grades of congestive heart failure, and higher 24-hour proteinuria. Higher rate of peritonitis and use of AG for the treatment of peritonitis is also associated independently with faster decline of residual GFR. Whether the type of PD (CAPD vs CCPD/NIPD) is associated with faster decline of residual GFR remains speculative.

Adult↗
PubMed2000

Pharmacokinetic studies of cyclosporin in Thai kidney transplantation patients.

Pharmacokinetic studies were performed in 10 Thai patients with kidney transplantation who received microemulsion formulation (Neoral) of cyclosporin A (CsA) twice daily. No agents having pharmacokinetic effect on CsA had been used in these patients. The mean values of 12-h AUC (area under the concentration-blood curve) were 4603.63 +/- 344.61 ng x h/ml. CsA concentrations at 2 hours after dosing had the best value of correlation coefficient with the 12-h AUC. Abbreviated AUC could be calculated by stepwise multiple linear regression analysis and linear trapezoidal rule. The latter is more simple and superior to the former one.

Adult↗
PubMed2001

An electronic documentation system increases diagnostic code capture for very low birth weight infants.

INTRODUCTION: Information describing medical interventions and patient outcome of very low birth weight (VLBW; BW <1500 grams) infants who receive neonatal intensive care is necessary to evaluate the quality of health care. We developed an electronic patient documentation system (EDS) called PCode to identify and select patient diagnostic (DX) codes and compared EDS to the previous paper-based documentation system (PDS). Our hypothesis was that EDS would capture more patient diagnostic codes than PDS. METHODS: PDS was originally developed as a two page 'code sheet' which listed all 275 neonatal diagnoses/management options and corresponding 3-4 character diagnostic (DX) codes, organized by organ system. PDS code sheets were manually completed by one of three trained 'coders' for every neonatal patient. EDS was developed as a Java application with the 'coder' selecting DX codes from drop lists also categorized by organ system. The study intervention was patient code selection using either the PDS or the EDS system. Both systems produced a paper DX code summary. PDS data capture occurred from 11/1997-3/1999 followed by EDS data capture until 8/2000. The primary outcome variable was DX codes captured per patient. Data were analyzed using independent t-test and linear regression. RESULTS: The number of diagnoses increased with decreasing birth weight. After linear regression was applied to control for birth weight, the number of DX codes was 31% greater in the EDS group, 7.2 +/- 2.9 DX codes/patient, p=0.008. There was a trend towards fewer erroneous DX codes in the EDS group. The most common DX codes were hyaline membrane disease, sepsis evaluation and hyperbilirubinemia, as expected for this patient population. CONCLUSIONS: EDS captured more VLBW infant DX codes compared to PDS. These results support the transition toward electronic data documentation for the neonatal clinical environment. Electronically linking PCode to the patient database has been initiated and should reduce manual coding errors.

Diagnosis↗
PubMed2002

Should a mucoadhesive patch (DentiPatch) be used for gingival anesthesia in children?

A local anesthetic-impregnated mucosal adhesive patch (DentiPatch) was compared with topical anesthetic (Hurricaine Dry Handle Swab) for gingival anesthesia before rubber dam clamp placement in children. Twenty-eight children needing sealants on their posterior teeth were enrolled in this study. Topical anesthesia was provided using either the mucoadhesive patch (20% lidocaine) or topical anesthetic (20% benzocaine). Subjects were randomized using a split mouth model. Either the patch or topical anesthetic was applied to the gingiva for 5 minutes or 1 minute, respectively. Subjects used a visual analog scale to describe their pain during the procedure. Linear regression and mixed linear models were used for data analysis. The visual analog scale results (pain scores) showed no significant difference between treatments. The mean per-child patch-sticking fraction was 29.7%. Patch adherence to oral mucosa increased with age in girls (P = .0045), but not in boys. The DentiPatch is as effective as, although not superior to, the Hurricaine Dry Handle Swab for gingival anesthesia before rubber dam clamp placement in children. These study results would not support the use of the DentiPatch for gingival anesthesia in children because of poor adherence to oral mucosa and the extra time necessary to apply and retain the device.

Adhesiveness↗
PubMed2003

Predicting the bioavailability of copper and zinc in soils: modeling the partitioning of potentially bioavailable copper and zinc from soil solid to soil solution.

This research produced statistically based, semimechanistic models describing partitioning of Cu and Zn in 40 soils from the United States, Canada, the United Kingdom (UK), The Netherlands, and Chile with widely varying characteristics. Two different types of models were constructed, partitioning models and competitive adsorption models. Multiple linear regression (MLR) was employed to prioritize over 30 different soil characteristics. Multiple linear regression yielded equations predicting the partitioning of Cu and Zn. Equations were also created that estimated the potentially bioavailable fraction of Cu and/or Zn. Data from plant uptake studies (which are reported separately) governed the choice of a suitable chemical soil extraction that estimated bioavailable Cu (0.01 M HCl) and bioavailable Zn (0.01 M CaCl2). Soil pH (1:1 soil:deionized water [DI H2O]) and percent organic matter accounted for approximately 70% of the variability in Cu partitioning and 80% of the variability in bioavailable Cu in the 40 soils studied. For Zn, soil pH alone accounted for roughly 75% of the partitioning variability and 80% of the variability for the estimated bioavailable portion. The results presented here were used in conjunction with results from the plant uptake studies for the creation of models to assess the potential bioavailable metal associated with any given soil from a wide variety of locations.

Adsorption↗
PubMed2004

Optimization of chitosan film as a substitute for animal and human epidermal sheets for in vitro permeation of polar and non polar drugs.

The present investigation is aimed at preparing chitosan films capable of simulating the flux of modal drugs, 5-fluorouracil (5-FU) and indomethacin (INDO), across rat, rabbit and human cadaver epidermal sheets. Application of statistical design revealed that the concentration of chitosan, crosslinking time and concentration of crosslinking agent significantly influenced the in vitro flux of 5-FU and INDO across chitosan films. Multiple linear regression revealed a linear influence of all these active variables on 5-FU and INDO flux. It was deduced from atomic absorption spectroscopic analyses, DSC and IR spectroscopic data that 5% (m/V) sodium tripolyphosphate (NaTPP) produced optimum crosslinking of chitosan films. The in vitro permeation of both 5-FU and INDO across optimized film formulations was found to be comparable to that obtained across rat, rabbit and human epidermal sheets. These results indicate that optimized chitosan films have a potential to be developed as a substitute for animal and human cadaver epidermal sheets for preliminary in vitro permeation studies.

Administration, Cutaneous↗