求翻译：然而卡铂的水溶性虽然较大，但是其不易通过血脑屏障，难以在颅内达到足够的浓度，更由于卡铂在体内的半衰期短作用于肿瘤的时间短，因而影响了疗效。是什么意思？

However carboplatin water-soluble, but it is not easy through the blood-brain barrier, it is difficult to achieve sufficient concentration in the intracranial, but also because of the short time of carboplatin in vivo half-life of short role in tumor, thus affecting the efficacy.

However card platinum of water soluble while larger, but its not easy through the blood brain barrier, it is difficult to achieve adequate in intracranial more because of the density, platinum card in the body of the short half-life in short time, the tumor has affected the efficacy.

正在翻译，请等待...

Carboplatin water-soluble while the larger, however, but it is not easy to pass the blood-brain barrier, it is difficult to reach sufficient concentrations of intracranial, more because of carboplatin tumor of the time, the short half-life in the body is short, thus affecting the curative effect.

However card platinum water-solubility although big, but it not easily through the blood brain barrier, with difficulty achieves the enough density in the skull, because the card platinum is shorter in vivo half-life short function in the tumor time, thus has affected the curative effect.