Pharmacokinetics describes the processes of absorption, distribution, and elimination of drugs and pharmacodynamics describes the effect of drugs on the body. Sedation can be performed by various classes of drugs each with its own mechanism of action and using varying routes of administration: oral, rectal, or parenteral. The course of sedation over time is a reflection of the relationship between pharmacokinetics and pharmacodynamics. The safety and efficacy of sedation is mainly dependant on understanding pharmacologic principles. This review will focus on the general concepts of the pharmacokinetics and pharmacodynamics of drugs used for sedation.
Absorption

BACKGROUND: Although sun-caps are widely used to shun hazardous solar ultraviolet (UV) radiation in Korea, little is known about their protective efficacy. OBJECTIVE: We tried to measure and compare sun-cap protection from UV radiation. METHODS: Seventeen commercially available sun-caps (products 1~17) were evaluated against UV-protection by spectrophotometerically measuring absorption and transmission spectra, percent protection of solar UVB and UVA photometerically, and solar UV-spectra spectroradiometerically. RESULTS: The absorption and transmission spectra of 17 different sun-caps were different, and they were not related to either price or their stated UV-guarantee. Percent protection showed some correlation, particularly with that of UVB. Protection against solar UV-spectra was similar to that of the absorption ond transmission spectra. CONCLUSION: Protection of sun-caps were highly varied, and this was not related to their price or stated UV- guarantee. Among three evaluation methods, absorption and transmission spectra seemed to be more objective. Further studies would be necessary to provide proper information and guidelines to dermatologists and consumers on the UV- protection of sun-caps.
Absorption ; Korea

No abstract available.
Absorption* ; Hysteroscopy*

BACKGROUND: A lot of protective tools such as sunshades (sun-cap), sun-shielding tints and various sunscreens are widely used to protect solar ultraviolet (UV) radiation. Although dermatologists are aware of these products, they do not know the exact protective efficacy or their stability after strong UV irradiation. OBJECTIVE: We tried to measure the spectal absorbance and transmittance of various sunscreening products. In addition, we measured change of sunscreens's absorbance or transmittance after strong UV irradiation for 30, 60 and 90 minutes. METHODS: We purchased five commercially available sunshades (product A-E), five sun-tinting films (product A-E), and eight sunsceens (product A-H) with similar sun-protection factor (SPF) around 30, and measured spectral absorbance and transmittance of those agents. For the sunscreens, they were irradiated with 250 watt Xenon-Arc lamp and change of spectral responses were evaluated. RESULTS: In absorption and transmission spectra of five different sun-caps, sun-cap C showed very good protection in entire UV range whereas all others protected UV only partially. Absorption and transmission spectra of six different sun-shielding tints showed all of them protected UV fairly well and tint C showed the best protection. Eight different sunscreens showed profound differences in spectal absorbances or transmittances. Sunscreen-A showed the best protection and there was no relationship between price and spectral-protection of sunscreens. In the photo-stability of eight sunscreens after UV-irradiation, there were big differences. Only sunscreen-A showed the least change after UV irradiation, and all other sunscreens showed a change of specta by increased UV-irradiation time. CONCLUSION: Protection efficacies of sunscreening products were variable, and most sunscreens were unstable to strong UV irradiation. Further studies would be necessary to give proper information for protecting UV effectively to dermatologists and consumers.
Absorption ; Sunscreening Agents

No abstract available.
Absorption* ; Drug Interactions*

Analyses of lead and zinc were made by means of standard addition method using atomic absorption spectrophotometer(Baird Ltd., Model A5100) with flameless method for lead and flame method for zinc. The blood samples used were merely diluted with triton x-100, because it was simple, rapid and minimal risk of contamination. Mean recovery rate for lead added to the blood ranged from 97.7 to 101.3% with coefficient of variation ranging from 1.9 to 10.7%, and that for the added zinc ranged from 99.0 to 102.2% with coefficient of variation ranging from 2.1 to 9.1%. In repeated measurements of zinc in the blood, good reproducibility and inter-individual variation were proved(p<0.01). In comparison of the lead and zinc concentrations in the blood determined by the standard addition method and standard method, there were good correlations between 2 sets of data (r=0.9731 for lead and r=0.9785 for zinc), although lead levels were estimated higher by the former method(p<0.01) and zinc levels by the latter method(p<0.01). It can be concluded that lead zinc levels in blood standard addition method is reliable for determination of lead and zinc in the blood with good accuracy and reproducibility.
Absorption ; Octoxynol ; Zinc*

This study investigated the recovery and absorption rates of murine norovirus, a surrogate for human norovirus, by using NanoCeram(R) filters which served as a tool for recovering viruses. In the study, two types of NanoCeram(R) filters were employed: one was a cartridge type and the other was a disc type (phi 47 mm) whose surface area is 75 times smaller than the cartridge type. The analytical method was the real-time reverse transcription-polymerase chain reaction (RT-PCR). The study found that the average recovery rates of the cartridge type and the disc type were 30.9% and 29.5% respectively. Since these two rates were very close to each other, the adsorption rate of the cartridge type could be predicted with the disc type. Analyzing recovery and absorption rates of the disc type based on different filtered volumes showed that when the volume increased from 0.5 L to 20 L, the average recovery rate rose from 14.78% to 30.41 %, while the average absorption rate dropped from 56.33% to 10.48%. The increase in turbidity from less than 1 NTU to less than 3 NTU raised the average recovery rate from 47.23% to 82.84%.
Absorption ; Adsorption ; Humans ; Norovirus

BACKGROUNDPrevious studies have suggested that nomogram can simplize complicated calculations of several variables. A simple nomogram was constructed to estimate absorption rate coefficient (k(a)) by using the peak time (tpeak) and the elimination rate coefficient (k(e)) of drugs administered orally.

METHODSThe nomogram was based on the plasma concentration-time (C-T) curve equation and the function relation between t(peak), k(a) and k(e). A mathematical analysis was presented for the construction of single chart nomogram. To check the degree of accuracy of the developed nomogram, we used it to analyze retrospective profiles of 46 drugs and compared the ka values obtained graphically and those calculated by numerically solving the descriptive equation. In addition, we measured the carbocisteine concentration of 18 healthy volunteers by HPLC with fluorescence detection. To analyze performance error, the measured carbocisteine concentrations were compared with predicted concentrations by the ka obtained from the nomograms along with the other pharmacokinetic parameters.

RESULTSThe estimated of k(a) values from nomograms were in very close proximity with the numerical values. The performance error was as follows: median performance error (MDPE) and median absolute performance error (MDAPE) were 1.32% and 18.15%, respectively.

CONCLUSIONSThe developed nomogram is accurate and reliable. The size of performance error meets the demand of clinical pharmacokinetics. Therefore, the nomograms can offer another convenient and easy method for rational individualized dosage regimens.

An observation on 15 individuals with exposure to mercury was made to see if there was any correlation between mercury levels in blood and urine. The data in this study have been subjected to statistical tests to support scientifically the validity of the results. (Summary)The Spearman coefficient of P = 0.015 and a correlation coefficient of 0.580 indicate a good correlation between the blood and urine levels on a group basis, although individually, there is no close correlation in any individual case. (Conclusion)
Absorption, Blood, Urine, Mercury

OBJECTIVES: We compared the effects of two different nano-sized calcium supplements (synthesized by wet-chemical method or the dry-grinding method of calcium carbonate) and one micro-sized calcium supplement (calcium carbonate) on intestinal absorption and bone turnover in 20 young women. MATERIALS & METHODS: This study was carried out with a three week cross-over design. The subjects ingested one of three different calcium supplements (1 dose of 500 mg Ca++) at 8 AM, which was repeated three times weekly. Serum and urine samples were collected before and after the calcium load using a time table (serum sampling 0, 2 hr, 4 hr, 8 hr after loading; urine sampling 0, 4 hr, 8 hr after loading). RESULTS: Serum ionized calcium and parathyroid hormone concentrations significantly changed in response to all calcium supplements loading, the difference among calcium supplements was not significant. However, the postload urinary excretion of calcium and the N-telopeptide/creatinine ratio were significantly different among three calcium supplement over time by repeated measured ANOVA. CONCLUSIONS: The results of this study suggest the effect of nano-sized calcium supplements synthesized by the wet-chemical method is superior to the other calcium supplements in intestinal calcium absorption and bone turn-over.
Absorption ; Calcium ; Cross-Over Studies ; Intestinal Absorption ; Parathyroid Hormone