Investigating Photochromic Behavior of Organic Dyes in Solution Form using Multilevel Factorial Design

Photochromic compounds, namely spiropyran, spirooxazine, and naphthopyran, have received much attention, because of their high potential applications in various industrial fields. The aim of this study is to understand the behavior of three photochromic dyes in solution form via statistical approach. The types of dyes and solvents were screened using multilevel factorial design. From the analysis of variance results, it was found that the types of dyes and solvents used as well as their interaction have significant effects on the absorbance and photostability. The naphthopyran compound displayed highest change in absorbance intensity, followed by spiropyran and spirooxazine, when dissolved in isopropanol separately. However, the spirooxazine is the most photostable dye compared to naphthopyran and spiropyran, with ethanol as the solvent. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Formulation and In vitro Evaluation of Piroxicam Conventional and Hollow Suppositories

Objective: The objective of this study was to develop a higher and rapid release of piroxicam from suppositories of different types (conventional and hallow) using different bases. Methods: Thirteen formulas (F1–F13) were prepared (five were conventional and the rest were hollow-type suppositories (HTS)] by using different bases, such as, witepsol H35, polyethylene glycols (PEGs) with a different ratio, and glycerinated gelatin. The prepared suppositories were evaluated for physical properties, such as, hardness, melting time, softening time, and dissolution profile. Results: All of the prepared suppositories had acceptable physical properties. The maximum percent release of piroxicam was 98, 97, 95, and 91% within 50 minutes were obtained from hollow-type suppositories containing piroxicam in a solution form and utilizing witepsol H35 base (F10), glycerinated gelatin base (F13), PEGs 400:4000 (70:30) (F12), and PEGs 200:6000 (70:30) (F11), respectively. Also, they exhibited rapid release of piroxicam however, F10 and F12 released 65 and 50% of piroxicam within 5 minutes, while, F11 released 57% within 10 minutes. Conclusion: Hollow type suppositories containing piroxicam in a solution form can be considered as the most suitable formulas (F10–F13). So, a hollow-type suppository is useful as a promising approach for enhancing the release of piroxicam to be administered rectally. Also, the study revealed that in addition to the type of suppositories, the type of the base, the grade, and the ratio of PEGs bases are other important factors affecting the physical properties of suppositories and the dissolution profile of piroxicam.

Formulation and In vitro Evaluation of Piroxicam Conventional and Hollow Suppositories

Objective: The objective of this study was to develop higher and rapid release of piroxicam from suppositories of different types (conventional and hollow) using different bases. Methods: Thirteen formulas (F1–F13) were prepared (five were conventional, and the rest were hollow type suppositories) by using different bases, such as, witepsol H35, polyethylene glycols (PEGs) with different ratio and glycerinated gelatin. The prepared suppositories were evaluated for physical properties, such as, hardness, melting time, softening time, and for dissolution profile. Results: All of the prepared suppositories had acceptable physical properties. The maximum percent release of piroxicam was 98, 97, 95, and 91% within 50 minutes were obtained from hollow type suppositories containing piroxicam in a solution form and utilizing witepsol H35 base (F10), glycerinated gelatin base (F13), PEGs 400:4000 (70:30) (F12), and PEGs 200:6000 (70:30) (F11), respectively. Also, they exhibited rapid release of piroxicam, however, F10 and F12 released 65 and 50% of piroxicam within 5 minutes, while, F11 released 57% within 10 minutes. Conclusion: Hollow type suppositories containing piroxicam in a solution form can be considered as the most suitable formulas (F10–F13). So, hollow-type suppository is useful as a promising approach for enhancing the release of piroxicam to be administered rectally. Also, the study revealed that in addition to the type of suppositories, the type of the base, the grade, and the ratio of PEGs bases are other important factors affecting the physical properties of suppositories and the dissolution profile of piroxicam.

Nonlinear Buckling Behavior of Spiral Corrugated Sandwich FGM Cylindrical Shells Surrounded by an Elastic Medium

This paper presents a semi-analytical approach for investigating the nonlinear buckling and postbuckling of spiral corrugated sandwich functionally graded (FGM) cylindrical shells under external pressure and surrounded by a two-parameter elastic foundation based on Donnell shell theory. The improved homogenization theory for the spiral corrugated FGM structure is applied and the geometrical nonlinearity in a von Karman sense is taken into account. The nonlinear equilibrium equation system can be solved by using the Galerkin method with the three-term solution form of deflection. An explicit solution form for the nonlinear buckling behavior of shells is obtained. The critical buckling pressure and the postbuckling strength of shells are numerically investigated. Additionally, the effects of spiral corrugation in enhancing the nonlinear buckling behavior of spiral corrugated sandwich FGM cylindrical shells are validated and discussed.

Evaluation of single-component chitosan fiber: from advanced materials to contemporary fashion manufacturing

Advancements in material science have driven the development of the textile industry. Chitosan has inherent advantages, such as biodegradability, nontoxicity, and antibacterial and wound acceleration properties. It has been applied in the textile industry as a coating on fabrics. Nevertheless, research on single-component chitosan fibers is scant. The advantages of single-component chitosan fibers include improved comfort, laundry durability, abrasion resistance, and structural flexibility. To fill the mentioned research gap, this study developed an industrial-manufacturing-based method for testing and analyzing chitosan fibers. This method was demonstrated by studying the physical and biological performance of commercial chitosan fibers. Studying the characteristics of the chitosan fibers revealed the influence of the fiber structure on their performance. Although chitosan fibers with a higher degree of deacetylation had a shorter molecular chain, they exhibited higher strength. Moreover, the molecular weight and deacetylation degree influenced biological performance. Chitosan fibers with higher deacetylation degree chitosan had better antimicroorganism performance on Staphylococcus aureus, Escherichia coli, and Candida albicans; however, no such relationship was observed for the solution form of chitosan. These results imply a difference in antimicroorganism mechanisms between the fiber (solid) form and solution form of chitosan.

FORMULATION AND IN VITRO EVALUATION OF PIROXICAM CONVENTIONAL AND HOLLOW SUPPOSITORIES

Objective: The objective of this study was to develop higher and rapid release of piroxicam from suppositories of different types (conventional and hallow) using different bases. Methods: Thirteen formulas (F1–F13) were prepared (five conventional and the rest were hollow type suppositories) by using different bases such as witepsol H35, polyethylene glycols (PEGs) with different ratio and glycerinated gelatin. The prepared suppositories were evaluated for physical properties such as hardness, melting time, softening time and for dissolution profiles. Results: All of the prepared suppositories had acceptable physical properties. The maximum percent release of piroxicam was 98%, 97%, 95% and 91% within 50 min were obtained from hollow type suppositories containing piroxicam in a solution form and utilizing witepsol H35 base (F10), glycerinated gelatin base (F13), PEGs 400:4000 (70:30) (F12) and PEGs 200:6000 (70:30) (F11), respectively. Also, they exhibited rapid release of piroxicam however, F10 and F12 released 65% and 50% of piroxicam within 5 min while, F11 released 57% within 10 min. Conclusion: Hollow type suppositories containing piroxicam in a solution form can be considered as the most suitable formulas (F10–F13). So that, the hollow-type suppository is useful as a promising approach for enhancing the release of piroxicam to be administered rectally. Also, the study revealed that in addition to the type of suppositories, the type of the base, the grade and the ratio of PEGs bases are other important factors affecting the physical properties of suppositories and the dissolution profile of piroxicam.

Perylene diimide–Cu2+ based fluorescent nanoparticles for the detection of spermine in clinical and food samples: a step toward the development of a diagnostic kit as a POCT tool for spermine

EA-PDI∩Cu2+ complex can be established as cost-effective method to develop diagnostic kit for POCT of spermine for real time detection of spermine in vapor and solution form released from fermented food samples.