ABSTRACT
With the commercial availability of a cream (EMLA) containing a eutectic mixture of local anaesthetics, 2.5% (w/w) lidocaine and 2.5% (w/w) prilocaine, effective topical anaesthesia of the intact skin is possible without the need for subcutaneous injections or exposure to high concentrations of local anaesthetics. In our hospital a topical anaesthetic product was designed for the same purpose. The home-made product contains a eutectic mixture of a local anaesthetic (5% w/w) and l-menthol (1% w/w). Prilocaine was used as the local anaesthetic because it is known for its safety and its well investigated analgesic effects. The eutectic mixture of prilocaine and l-menthol was mixed with a carbopol hydrogel (1% w/w). Preliminary testing of this anaesthetic hydrogel in our hospital has yielded satisfactory results. The anaesthetic hydrogel was found to be stable after at least 3 months' storage at ambient temperature.
Subject(s)
Anesthetics, Local/administration & dosage , Anesthetics, Local/chemistry , Lidocaine/administration & dosage , Lidocaine/chemistry , Prilocaine/administration & dosage , Prilocaine/chemistry , Administration, Topical , Antipruritics/administration & dosage , Antipruritics/chemistry , Chemistry, Pharmaceutical , Drug Combinations , Drug Stability , Lidocaine, Prilocaine Drug Combination , Menthol/administration & dosage , Menthol/chemistryABSTRACT
Iodine-131 radioiodinated meta-iodobenzylguanidine (131I-MIBG) is used for diagnostic scintigraphy and radionuclide therapy of neural crest-derived tumours. In higher doses (up to 80 mg), non-radioactive MIBG is now evaluated for palliation in carcinoid patients. After administration of therapeutic doses of 131I-MIBG (3.7-7.4 GBq, 1.7-5.8 mg MIBG) to patients aged 2-73 years, 53 +/- 8.8%, 69 +/- 7.8% and 83 +/- 7.0% of the dose was cumulatively excreted as MIBG in the urine after 24, 48 and 72 h, respectively. Within the MIBG dose range of 1.7-80.0 mg, a linear relationship was found between the excretion rate over the first 24 h (mg per 24 h) and the dose. In adults, the MIBG excretion rate over the first 24 h (% of dose per 24 h) was shown to be only partially related to the glomerular filtration rate (GFR).
Subject(s)
Iodine Radioisotopes/pharmacokinetics , Iodine Radioisotopes/therapeutic use , Iodobenzenes/pharmacokinetics , Iodobenzenes/therapeutic use , Neoplasms/radiotherapy , 3-Iodobenzylguanidine , Adolescent , Adrenal Gland Neoplasms/radiotherapy , Adult , Age Factors , Aged , Carcinoid Tumor/radiotherapy , Child , Child, Preschool , Creatinine/metabolism , Humans , Iodine Radioisotopes/urine , Iodobenzenes/urine , Metabolic Clearance Rate , Middle Aged , Neuroblastoma/radiotherapy , Pheochromocytoma/radiotherapyABSTRACT
An accurate, sensitive, reproducible and selective HPLC assay is presented for the quantitative determination of m-iodobenzylguanidine (MIBG) in human urine. The sample pretreatment involves a solid-phase extraction on Bakerbond SPE cyano columns. The HPLC systems consists of a muBondapak C18 column and 25 mM ammonium phosphate (pH 3.0)-acetonitrile (75:25, v/v) as the mobile phase. Detection is performed by UV absorbance at 254 nm. Log y vs. log x is the response function that yielded the smallest sum of percent relative concentration residuals over the whole concentration range of the assay (0.2-100 micrograms/ml). The excretion profile of MIBG in urine of a three-year old patient is shown.
