Search

The purpose of this study was to develop a novel d‐cycloserine tablet with improved stability and dissolution equivalent to the d‐cycloserine‐loaded commercial hard capsule. The effect of alkalizing agents on the d‐cycloserine was investigated. Numerous d‐cycloserine tablets were prepared with various calcium hydroxide contents, using direct or wet granulation compression, and their stability and dissolution were assessed compared to the commercial d‐cycloserine‐loaded hard capsule. Long‐term stability of the selected d‐cycloserine tablet in aluminum polyvinylchloride blister were conducted at 25 °C/60% RH or 40 °C/75% RH for 6 months. Amongst the stabilizers tested, calcium hydroxide gave the best stability at 60 °C/75% RH for 2 days due to its alkaline and waterproofing properties. Calcium hydroxide hardly affected dissolution of drug from the tablets but considerably increased stability of drug in the tablets. Particularly, the tablet prepared with d‐cycloserine, calcium hydroxide, polyvinylpyrrolidone, and talc in the weight ratio of 250/250/40/7.5 using direct compression gave similar dissolution but significantly improved stability compared to the commercial hard capsule. This tablet, packaged in aluminum polyvinylchloride blister, was stable in the above accelerated conditions for 6 months. Therefore, this novel d‐cycloserine tablet with enhanced stability and dissolution equivalent to the commercial hard capsule would be recommended as an alternative. [ABSTRACT FROM AUTHOR]

The purpose of this study was to improve the chemical stability of D‐cycloserine via tablet form containing an alkali stabilizer. The influence of alkalizing agents on the stability of D‐cycloserine was investigated at 60 °C/75% RH for 2 days. The drug stability was evaluated with the D‐cycloserine‐loaded tablets prepared with various amounts of magnesium oxide using direct compression method. Compared to D‐cycloserine powder and a commercial D‐cycloserine‐loaded product, the long‐term drug stability on the chosen tablet was assessed at 40, 60, and 40 °C/75% RH during 6 months. Amongst the stabilizers investigated, magnesium oxide most improved the stability of D‐cycloserine at the accelerated stress condition. The magnesium oxide/drug ratio of 1 and 2 showed higher remaining drug concentrations than those less than 0.5; however, two formers gave no significant difference in the remaining drug concentrations. Amongst the tablets tested, the formulation composed of D‐cycloserine, magnesium oxide, and talc at the weight ratio of 250/250/5 most increased the stability of D‐cycloserine. Additionally, due to the alkali and water‐proofing property of magnesium oxide, this tablet improved the stability of D‐cycloserine compared to the drug powder and commercial product. Hence, this novel tablet with enhanced drug stability would be a candidate for oral pharmaceutical product of D‐cycloserine. [ABSTRACT FROM AUTHOR]

In the past decade, the self-immolative biodegradable polymer arose as a novel paradigm for its efficient degradation mechanism and vast potential for advanced biomedical applications. This study reports successful synthesis of a novel biodegradable polymer capable of self-immolative backbone cleavage. The monomer is designed by covalent conjugations of both pendant redox-trigger (p-nitrobenzyl alcohol) and self-immolative linker (p-hydroxybenzyl alcohol) to the cyclization spacer (n-2-(hydroxyethyl)ethylene diamine), which serves as the structural backbone. The polymerization of the monomer with hexamethylene diisocyanate yields a linear redox-sensitive polymer that can systemically degrade via sequential 1,6-elimination and 1,5-cyclization reactions within an effective timeframe. Ultimately, the polymer's potential for biomedical application is simulated through in vitro redox-triggered release of paclitaxel from polymeric nanoparticles. [ABSTRACT FROM AUTHOR]