Conductometric and spectrophotometric studies of self-aggregation behavior of streptomycin sulphate in aqueous solution: Effect of electrolytes

Free radical synthesis of succinic anhydride grafted poly(lactic acid) porous templates for sustained drug delivery in the buffer media

Poly(lactic) (PLA) is a biodegradable material obtained from renewable resources and is recognized as a safe biopolymer by the Food and Drug Administration. PLA expresses excellent mechanical and moldability attributes nonetheless poor elasticity/functionality limits its widespread utilization. One approach to compensate for this is chemical surface modification through free radical grafting with small organic molecules like maleic anhydride (MA). The study undertakes the synthesis of succinic anhydride (SA)-grafted PLA [SA-g-PLA] films for sustained drug delivery applications. The entrapped porogen was leached out under alkaline treatment to make the PLA film porous by creating channels/cavities for drug inclusion. The success of the surface treatment of PLA-based films was investigated using specific chemical analyses. The results demonstrated the hydrophilic nature (water contact angle of 31°) of the SA-g-PLA films for the prevalence of MA (1780 cm-1) and methylamine (340-640 cm-1) congeners as expressed under FTIR analysis. The SA-g-PLA film expressed a crystallinity of 72.41 % and a melting temperature of 201.9 °C. The SA-g-PLA film exhibited pH-responsive streptomycin sulfate uptake (pH 6.5) and release (pH 7.4) profiles and obeyed first-order kinetics. The SA-g-PLA porous films with potential modification would be a sustainable and biocompatible candidate for drug delivery applications.

Aggregation phenomena and physico-chemical properties of tetradecyltrimethylammonium bromide and protein (bovine serum albumin) mixture: Influence of electrolytes and temperature

It is important for biological, pharmaceutical, and cosmetic industries to understand how proteins and surfactants interact. Herein, the interaction of bovine serum albumin (BSA) with tetradecyltrimethylammonium bromide (TTAB) in different inorganic salts (KCl, K2SO4, K3PO4.H2O) has been explored through the conductivity measurement method at different temperatures (300.55 to 325.55 K) with a specific salt concentration and at a fixed temperature (310.55 K) using different salts concentrations. The extent of micelle ionization (α) and different thermodynamic parameters associated with BSA and TTAB mixtures in salt solutions were calculated. Evaluation of the magnitudes of ∆Hm0 and ∆Sm0 showed that the association was exothermic and primarily an enthalpy-operated process in all cases at lower contents of BSA, but the system became endothermic, and entropy driven in the presence of K3PO4.H2O at a relatively higher concentration of BSA. The enthalpy-entropy compensation variables were determined, which explained the types and nature of interactions between TTAB and BSA in salt media. Molecular docking analysis revealed that the main stabilizing factors in the BSA-TTAB complex are electrostatic and hydrophobic interactions. These findings aligned with the significant results obtained from the conductometry method regarding the nature and characteristics of binding forces observed between BSA and TTAB.

Investigation of the impacts of simple electrolytes and hydrotrope on the interaction of ceftriaxone sodium with cetylpyridinium chloride at numerous study temperatures

Herein, interactions between cetylpyridinium chloride (CPC) and ceftriaxone sodium (CTS) were investigated applying conductivity technique. Impacts of the nature of additives (e.g. electrolytes or hydrotrope (HDT)), change of temperatures (from 298.15 to 323.15 K), and concentration variation of CTS/additives were assessed on the micellization of CPC + CTS mixture. The conductometric analysis of critical micelle concentration (CMC) with respect to the concentration reveals that the CMC values were increased with the increase in CTS concentration. In terms of using different mediums, CMC did not differ much with the increase in electrolyte salt (NaCl, Na2SO4) concentration, but increased significantly with the rise of HDT (NaBenz) amount. In the presence of electrolyte, CMC showed a gentle increment with temperature, while the HDT showed the opposite trend. Obtained result was further correlated with conventional thermodynamic relationship, where standard Gibb's free energy change ( Δ G m o ) , change of enthalpy ( Δ H m o ) , and change of entropy ( Δ S m o ) were utilized to investigate. The Δ G m o values were negative for all the mixed systems studied indicating that the micellization process was spontaneous. Finally, the stability of micellization was studied by estimating the intrinsic enthalpy gain (Δ H m o , ∗ ) and compensation temperature (Tc). Here, CPC + CTS mixed system showed more stability in Na2SO4 medium than the NaCl, while in NaBenz exhibited the lowest stability.