Lidocaine Cyclodextrin complex Ophthalmic Drop, a New Topical Anesthetic Choice.

BACKGROUND: Topical anesthesia is a safe and cost-effective method considered as the first-choice in many procedures. Due to the physiological characteristics of eye, most of the local anesthetics cannot efficiently penetrate through the conjunctiva deep to tenon. The aim of this pilot study was to find a new form of lidocaine to give a sufficient level of anesthesia. METHODS: Lidocaine Cyclodextrin complex ophthalmic drop was produced and its pharmacological properties were studied [tested] in standard temperature and pressure. 30 patients (18 males, 12 females) with the mean age of 30.68±8.02 years enrolled in this clinical trial. All the patients were fully informed and signed the ethics committee consent forms. The patients were given tetracaine drop as the anesthetic: 3 drops separated 2 minute apart 10 min before the intervention. If we achieved a sufficient level of anesthesia, the procedure was done after. If the patient could not tolerate the procedure, the method was changed to lidocaine drop (administered after wash-out period like the first drop).The last option was conventional injection method if the patient could not tolerate the procedure with the second method either.We used this type of anesthesia for conventional procedures such as forced duction test, symblepharon, pterygium, and disport injection into extra-ocular muscles. All the procedures were done by one surgeon in a university hospital. We used a 0 to 10 visual analogue scale for pain and two 0 to 4 patient and physician satisfaction scales designed for this study. RESULTS: The mean pain score was 7.53±0.90 in group 1 and 3.03±1.83 in group 2 (P=0.00). Patient and surgeon satisfaction in group 1 were 1.33±0.48 and 1.40±0.56 respectively; while 3.23±1.00 and 3.56±0.77 for group 2 (P=0.00). Tetracaine drop could not induce sufficient anesthesia for none of the patients. Cyclodextrin based lidocaine drop was successful except For two patients for whom we changed the anesthesia to Sub-conjunctival injection method. CONCLUSION: Our newly manufactured cyclodextrin based lidocaine eye drop could successfully induce sufficient anesthesia for 28 of 30 patients. Further studies with larger sample sizes are now being designed to find more clinical evidence about this method.

Estimation of abbreviated mycophenolic acid area under the concentration-time curve during early posttransplant period by limited sampling strategy.

Area under the concentration curve (AUC) of mycophenolic acid (MPA) could help to optimize therapeutic drug monitoring during the early post-renal transplant period. The aim of this study was to develop a limited sampling strategy to estimate an abbreviated MPA AUC within the first month after renal transplantation. In this study we selected 19 patients in the early posttransplant period with normal renal graft function (glomerular filtration rate > 70 mL/min). Plasma MPA concentrations were measured using reverse-phase high-performance liquid chromatography. MPA AUC(0-12h) was calculated using the linear trapezoidal rule. Multiple stepwise regression analysis was used to determine the minimal and convenient time points of MPA levels that could be used to derive model equations best fitted to MPA AUC(0-12h). The regression equation for AUC estimation that gave the best performance was AUC = 14.46 C(10) + 15.547 (r(2) = .882). The validation of the method was performed using the jackknife method. Mean prediction error of this model was not different from zero (P > .05) and had a high root mean square prediction error (8.06). In conclusion, this limited sampling strategy provided an effective approach for therapeutic drug monitoring during the early posttransplant period.

Cooperative alpha-helix formation of beta-lactoglobulin induced by sodium n-alkyl sulfates.

It is generally assumed that folding intermediates contain partially formed native-like secondary structures. However, if we consider the fact that the conformational stability of the intermediate state is simpler than that of the native state, it would be expected that the secondary structures in a folding intermediate would not necessarily be similar to those of the native state. beta-Lactoglobulin is a predominantly beta-sheet protein, although it has a markedly high intrinsic preference for alpha-helical structure. The formation of non-native alpha-helical intermediate of beta-lactoglobulin was induced by n-alkyl sulfates including sodium octyl sulfate, SOS; sodium decyl sulfate, SDeS; sodium dodecyl sulfate, SDS; and sodium tetradecyl sulfate, STS at special condition. The effect of n-alkyl sulfates on the structure of native beta-lactoglobulin at pH 2 was utilized to investigate the contribution of hydrophobic interactions to the stability of non-native alpha-helical intermediate. The addition of various concentrations of n-alkyl sulfates to the native state of beta-lactoglobulin (pH 2) appears to support the stabilized form of non-native alpha-helical intermediate at pH 2. The m values of the intermediate state of beta-lactoglobulin by SOS, SDeS, SDS and STS showed substantial variation. The enhancement of m values as the stability criterion of non-native alpha-helical intermediate state corresponded with increasing chain length of the cited n-alkyl sulfates. The present results suggest that the folding reaction of beta-lactoglobulin follows a non-hierarchical mechanism and hydrophobic interactions play important roles in stabilizing the non-native alpha-helical intermediate state.