Infrared spectral comparison of 5-aminolevulinic acid and its hexyl ester

Chen, J.Y.; Peng, Qian; Jodl, H. J.

doi:10.1016/s1386-1425(03)00011-8

Cited by 17 publications

(8 citation statements)

References 10 publications

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“…This is said to be the functional group region, where the primary functional groups absorb [29]. The IR spectrum of the compound synthesised is in agreement with IR spectrum for h-ALA reported by Chen et al [30]. Fig .…”

Section: Resultssupporting

confidence: 83%

Practical Considerations in the Pharmaceutical Analysis of Methyl and Hexyl Ester Derivatives of 5-Aminolevulinic Acid

Morrow¹,

McCarron²,

Woolfson³

et al. 2009

TOACJ

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Photodynamic therapy (PDT) using topical 5-aminolevulinic acid (ALA), a water-soluble precursor of the potent endogenous photosensitiser, protoporphyrin IX (PpIX), is a treatment and diagnostic tool for premalignant and malignant skin cancers. However, to improve drug delivery to deeper skin lesions, more lipophilic ALA esters have been investigated. Owing to the necessity in drug delivery research for efficient and validated assays for ALA esters in solution, this paper aims to describe optimised protocols to quantify the methyl and hexyl esters of ALA.ALA esters were derivatised using acetyl acetone and formaldehyde reagents and analysed using reversed phase HPLC. For the first time, the significance of ALA-impurities in ester samples has been highlighted. Furthermore, it was shown that for a given concentration, peak areas obtained for ALA-esters were significantly smaller than those obtained for ALA (p < 0.05). This may be due to parent drug undergoing the derivatisation reaction more efficiently or because the ALAderivate is inherently more fluorescent than the ester derivatives. The method was optimised to give acceptable intra-and inter-day variability (CV values < 5%) and the limits of detection and quantification were determined for both drugs.The validated methods were used to determine the release profiles of ALA, m-ALA and h-ALA from an o/w cream formulation. The percentage of drug loading released after five hours across a model membrane was in the order of ALA (45.2%) > m-ALA (38.3%) > h-ALA (33.9%). These findings may explain why, historically, some of the benefits seen with ALA-esters using cell culture models have not been demonstrated in vivo.

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Section: Resultssupporting

confidence: 83%

Practical Considerations in the Pharmaceutical Analysis of Methyl and Hexyl Ester Derivatives of 5-Aminolevulinic Acid

Morrow¹,

McCarron²,

Woolfson³

et al. 2009

TOACJ

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“…In He-ALA (15) spectrum, an additional CH(3) peak appears [94]. However, the quantification of mixtures of both compounds would not be possible by this method.…”

Section: B61 Systemic Administration and Topical Application Of Alamentioning

confidence: 99%

Aminolevulinic Acid Derivatives and Liposome Delivery as Strategies for Improving 5-Aminolevulinic Acid- Mediated Photodynamic Therapy

Casas¹,

Batlle²

2006

CMC

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Photodynamic Therapy employing 5-aminolevulinic acid (ALA) as a precursor of the photosensitizer Protoporphyrin IX has become a promising approach to treat superficial cancers. However, the hydrophilic nature of the ALA molecule somewhat limits the penetration through the skin as well as all cell membranes. Different attempts are currently under investigation to enhance ALA penetration, such as the development of new synthetic and more lipophilic molecules derived from ALA and the incorporation of ALA into lipophilic vehicles such as liposomes. Among the new synthesized molecules, we can find ALA esters, ALA aminoacid derivatives and ALA dendrimers. In general, there is consensus that the promising results obtained in vitro with ALA esters cannot be reproduced in vivo. However, ALA methyl ester (1) has been widely used for treatment of skin malignancies and ALA hexyl ester (15) proved to be more powerful than ALA in bladder imaging. ALA aminoacid derivatives have been designed to use specific cellular aminopeptidases to targeting tumors, and it was shown that they can be metabolized to ALA with some specificity.

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“…In addition, the vibration bands at 2858.51 and 2924.09 cm À1 belong to the CH 2 and [sbond]CH 3 groups of BOC and 5-ALA. The shoulder around 1700 cm À1 belongs to the C[dbond]O group of folate in FA-5ALA-conjugated Bi 2 O 3 NPs[30]. Moreover, the band at 1400-1600 cm À1 and peak at 1083.99 cm À1 is apportioned to bending vibration mode of aromatic C=C of FA in FA-5ALA-conjugated Bi 2 O 3 NPs[31].Figure 3(B), shows the comparison of FA-5ALA-conjugated Bi 2 O 3 NPs with free 5-ALA and folate.…”

mentioning

confidence: 99%

Evaluating the photodynamic therapy efficacy using 5-aminolevulinic acid and folic acid-conjugated bismuth oxide nanoparticles on human nasopharyngeal carcinoma cell line

Akbarzadeh

Khoshgard

Arkan

et al. 2018

Artificial Cells, Nanomedicine, and Biotechnology

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Selective accumulation of photosensitizers (PSs) into cancerous cells is one of the most important factors affecting photodynamic therapy (PDT) efficacy. 5-Aminolevulinic acid (5-ALA) is precursor of a strong PS, protoporphyrin-IX (Pp-IX); but it has poor permeability in lipophilic membrane of the cells due to its hydrophilic property. Therefore, establishment of an improved delivery strategy could highly affect on treatment outcome. Moreover, folate receptors (FRs) are overexpressed on the surface of many tumor cells. In the present work, targeting ligand folic acid (FA) and 5-ALA conjugated bismuth oxide nanoparticles (FA-5ALA-Bi 2 O 3 NPs) were synthesized; and used in PDT against human nasopharyngeal carcinoma cells (KB cell line). The KB cells incubated with the synthesized NPs for 2 h; then illuminated using a custom-made red light LED lamp at the light dose of 26 J/cm 2. MTT and caspase-3 activity assays were performed to evaluate the efficacy of treatment. Results showed that FR targeting ligand enables selective endocytosis of FA-5-ALA-conjugated NPs into KB cells. Improved internalization of 5-ALA into cells decreased the cell viability to about 50%, 65%, and 85% in the groups receiving FA-5ALA-Bi 2 O 3 NPs, 5ALA-Bi 2 O 3 NPs, free 5-ALA and subsequent PDT, respectively. Therefore, FA-5ALA-Bi 2 O 3 NPs can significantly increase the cell killing effect of PDT.

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Infrared spectral comparison of 5-aminolevulinic acid and its hexyl ester

Cited by 17 publications

References 10 publications

Practical Considerations in the Pharmaceutical Analysis of Methyl and Hexyl Ester Derivatives of 5-Aminolevulinic Acid

Practical Considerations in the Pharmaceutical Analysis of Methyl and Hexyl Ester Derivatives of 5-Aminolevulinic Acid

Aminolevulinic Acid Derivatives and Liposome Delivery as Strategies for Improving 5-Aminolevulinic Acid- Mediated Photodynamic Therapy

Evaluating the photodynamic therapy efficacy using 5-aminolevulinic acid and folic acid-conjugated bismuth oxide nanoparticles on human nasopharyngeal carcinoma cell line

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