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Biomedical subjects

A Khosravi

Publications and source records attributed to A Khosravi.

3 recordsLinked to original sources
PubMed1999

Release of 5-amino salicylic acid from acrylic type polymeric prodrugs designed for colon-specific drug delivery.

New acrylic type polymeric systems having degradable ester or amide bonds linked to the bioactive agent 5-amino salicylic acid (5-ASA), were prepared and evaluated as materials for colon-specific drug delivery. Methacryloyloxyethyl 5-amino salicylate (MOES), and N-methacryloylaminoethyl 5-amino salicylamide (MAES) were prepared as the polymerizable derivatives of 5-ASA using activated ester methodology. The drug-containing monomers were free radically copolymerized with methacrylic acid or hydroxyethyl methacrylate, utilizing azobisisobutyronitrile as initiator. The polymer bearing 5-ASA units as side substituents of the acrylic backbone were obtained in the form of poly pendent esters or poly pendent amides. The drug release studies were performed by hydrolysis in buffered solutions (pH 1, 7.2, 8.5), or simulated intestinal fluid containing pancreatin to measure the chemical degradation expected to occur in the intestinal tract. The release profiles indicated that the hydrolytic behavior of polymers strongly depends on their degree of swelling, type of comonomer, and the nature of hydrolyzable bond. Implication of the results for use of these polymers for colon targeting are discussed.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

Determination of captopril in human serum by high performance liquid chromatography using solid-phase extraction.

A rapid, simple and sensitive assay was developed for determination of captopril in human serum. We employed silica gel cartridge for efficient extraction of captopril adduct from human serum. Captopril was trapped with p-bromophenacyl bromide (pBPB) to give captopril-pBPB adduct. A 4-ml benzene extract of 1 ml acidified serum was passed through 1 ml silica gel cartridge. Potential interfering compounds were removed with 4-ml benzene wash. The captopril-pBPB adduct was eluted with 0.5 ml acetonitrile. Of this acetonitrile solution (100 microliters) was injected on an ODS reverse phase HPLC column (chromatography conditions; mobile phase; acetonitrile-water-acetic acid (225:270:5, v/v/v), flow rate; 1 ml min-1, detection; UV at 263 nm). It is found that this method is accurate and does not require time consuming evaporation-concentration steps. Recovery exceeds 94% and analytical responses are linear over captopril concentration range from 50 up to 1000 ng ml-1. The coefficients of variation from 108 ng ml-1 to 605 ng ml-1 varied between 3.7-7.7% and the relative error did not exceed 3.7%. Therefore, this method can be used for routine clinical monitoring and in pharmacokinetic studies of captopril.

Angiotensin-Converting Enzyme Inhibitors↗