High-performance liquid chromatographic determination of 2-hydroxypropyl-gamma-cyclodextrin in different biological fluids based on cyclodextrin enhanced fluorescence.

A high-performance size exclusion chromatographic method with analyte enhanced fluorescence detection is described for the analysis of 2-hydroxypropyl-gamma-cyclodextrin (HPGCD) in different biological fluids. The principle of detection was the in situ complexation of 8-anilinonaphthalene-1-sulfonic acid (ANS) by HPGCD. When HPGCD eluted from the column the increased fluorescence was measured at excitation and emission wavelengths of 270 and 512 nm, respectively.

Cyclodextrins in oligonucleotide delivery.

The aim of this contribution is to summarize recent findings on the potential use of cyclodextrins and their derivatives as carriers for oligonucleotide agents. Their peculiar properties could be exploited in such an emerging therapeutic area by virtue of their capability of interacting with cellular membranes, thus giving rise to improved cellular uptake. In particular, some specific derivatives could be considered as promising future excipients for the delivery of "naked" antisense and/or decoy oligonucleotides which are difficult to formulate with existing pharmaceutical excipients.

Safety of parenteral hydroxypropyl beta-cyclodextrin.

Post-treatment data were collected on a patient who received intravenous hydroxypropyl beta-cyclodextrin in a dose of 1.5 g/kg in 1985. Although no untoward effects were observed in this patient, rarely occurring agitation and pulmonary edema have been noted after injections into rabbits and dogs, respectively.

Parenteral hydroxypropyl cyclodextrins: intravenous and intracerebral administration of lipophiles.

Hydroxypropyl cyclodextrins are nontoxic carbohydrate derivatives of moderate molecular weight (1030-1750 Da) which form water-soluble complexes with many lipophiles. The fate of hydroxypropyl beta-cyclodextrin alone and in complex with testosterone or cholesterol injected intravenously or intracerebrally into rats was followed. More than 90% of intravenously administered hydroxypropyl beta-cyclodextrin was cleared into urine in 4 h, as previously described (Monbaliu, J.

Safety of oral cyclodextrins: effects of hydroxypropyl cyclodextrins, cyclodextrin sulfates and cationic cyclodextrins on steroid balance in rats.

Derivatives of beta-cyclodextrin differing in the length of a hydroxyalkyl substituent (CH2CH2OH, CH2CHOHCH3, CH2CHOHCH2CH2CH2CH3) or in the electrical charge of the substituents (SO4-, CH2CHOHCH2N(CH3)3+) and hydroxypropyl derivatives (CH2CHOHCH3) of alpha-, beta-, and gamma-cyclodextrin were compared, individually and in mixtures, as solubilizers of cholesterol. The most effective solubilizer proved to be hydroxypropyl derivatives of beta-cyclodextrin; beta-cyclodextrin sulfate (SO4-) was practically devoid of solubilizing activity. Oral administration of these cyclodextrin derivatives, some of which are both nondegradable and effective complexation agents for cholesterol and bile acids, nevertheless did not affect the conversion of [14C]acetic acid to [14C]-cholesterol in rat under the same conditions when another bile acid complexation agent, cholestyramine, increased that conversion.

Suppositories containing cyclodextrin complexes. Part 2: Dissolution and absorption studies.

The dissolution and absorption of poorly water-soluble drugs from rectal suppositories can be enhanced by complexing these substances (e.g., essential oils, indomethacin) with beta-cyclodextrin.

Absorption, distribution, excretion and metabolism of orally administered 14C-beta-cyclodextrin in rat.

The absorption, distribution, excretion and metabolism of orally administered universally labelled 14C-beta-cyclodextrin and 14C-glucose were compared in rat. The maximum radioactivity of the blood derived from 14C-beta-cyclodextrin was observed between 4th and 11th h and the value of the maximum in different experiments ranged between 5 and 17 0/00 of the total administered radioactivity. Following 14C-glucose treatment radioactivity reached the maximum within half-an-hour, with values of 15 to 82 0/00.

Improvement of the absorption of 3H-Cholecalciferol by formation of its cyclodextrin complex.

Following oral administration to rats of beta-cyclodextrin inclusion complex of 3H-labelled vitamin D3 (cholecalciferol) resulted in significantly higher blood radioactivity as with the non-complexed vitamin. Difference in the first 90 min was 2,3-2,8 fold, and it remained significantly higher up to the 6th h. After 24 h there was no difference between the blood radioactivity of animals treated with complexed and with non-complexed vitamin D3.

Influencing of resorption and side-effects of salicylic acid by complexing with beta-cyclodextrin.

After oral administration of 14C-labelled salicylic acid and its beta-cyclodextrin complex to rats, the blood radioactivity-level increases in the first 2 h than decreases. The blood level obtained with the inclusion complex is somewhat but not significantly lower than with free acid. Since the resorption of cyclodextrin is a considerably slower process, it is very likely that the resorption of salicylic acid take place in the form of free acid after dissociation of the complex.

Intestinal absorption of 14C-labelled beta-cyclodextrin in rats.

beta-Cyclodextrin and glucose labelled universally by 14C was administered orally to rats and blood radioactivity level was followed. In the case of glucose about 20% of the administered radioactivity, related to 10 ml blood was to be found and this appeared in the blood within 10 min following the oral administration. In the case of beta-cyclodextrin maximum 5% of the administered activity could be found in blood, and even this only 4 to 10 h following administration.

Transport parameters and stoichiometry of active calcium ion extrusion in intact human red cells.

Ca2+-transport and its energy consumption were studied in intact human red cells loaded with Ca2+ by the aid of the ionophore A23187. After the complete elimination of the ionophore the passive Ca2+-permeability of the membrane returned to its normal low value, except when the intracellular Ca2+-concentration was higher than 3 mM or the ATP level fell below 100 muM. Within these limits the rate of Ca2+-extrusion was independent of the cellular ATP content but was greatly enhanced by increasing [Ca2+]i and reached a plateau at about 1 mM intracellular Ca2+-concentration.