Introduction: The current work was aimed to design and synthesize novel crosslinked pH-sensitive gelatin/pectin (Ge/Pec) hydrogels using different polymeric ratios and to explore the effect of polymers and degree of crosslinking on dynamic, equilibrium swelling and in vitro release behavior of the model drug (Mannitol). Methods: The Ge/Pec based hydrogels were prepared using glutaraldehyde as the crosslinker. Various structural parameters that affect their release behavior were determined, including swelling study, porosity, sol-gel analysis, average molecular weight between crosslinks (Mc), volume fraction of polymer (V2,s), solvent interaction parameter (χ) and diffusion coefficient. The synthesized hydrogels were subjected to various characterization tools like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and DSC differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Results:The hydrogels show highest water uptake and release at lower pH values. The FTIR spectra showed an interaction between Ge and Pec, and the drug-loaded samples also showed the drug-related peaks, indicating proper loading of the drug. DSC and TGA studies confirmed the thermal stability of hydrogel samples, while SEM showed the porous nature of hydrogels. The drug release followed non-Fickian diffusion or anomalous mechanism. Conclusion: Aforementioned characterizations reveal the successful formation of copolymer hydrogels. The pH-sensitive swelling ability and drug release behavior suggest that the rate of polymer chain relaxation and drug diffusion from these hydrogels are comparable which also predicts their possible use for site-specific drug delivery.

Bu çalışmada, her bir polimerin farklı oranları kullanılarak pH duyarlı çapraz bağlı jelatin/sodyum aljinat hidrojellerinin tasarlanması ve sentezlemesi ve her bir polimerin dinamik, kararlı şişme ve model etken madde olarak seçilen setirizin hidroklorürün in vitro salım profiline etkisinin araştırılması amaçlanmıştır. Gereç ve Yöntemler: Bu jelatin ve sodyum aljinat hidrojelleri, oda sıcaklığında, çapraz bağlayıcı olarak glutaraldehitin kullanımıyla serbest radikal polimerizasyonu ile hazırlandı. Bu polimerik kompozitler, çeşitli önemli karakterizasyonları öngörmek için model sistemler olarak kullanıldı. Etken maddelerin in vitro salım modeli üç farklı ortamda (pH 1.2, 5.5, 7.5 iyonik kuvveti sabit tutulan fosfat tampon çözeltisi) araştırıldı. Solunum analizi, gözeneklilik, sol-jel analizi, çapraz bağlar arasındaki ortalama molekül ağırlığı (Mc), çözücü etkileşim parametresi (χ), polimerin hacim fraksiyonu (V 2,s) ve difüzyon gibi salım davranışını etkileyen çeşitli yapı özellik ilişkileri belirlendi. FTIR, XRD ve DSC analizi kullanılarak yapı, kristalinite ve termal stabilite doğrulandı. Objectives: The present work aimed to design and synthesize pH-sensitive cross-linked Ge/SA hydrogels using different ratios of each polymer, and to investigate the effect of each polymer on dynamic, equilibrium swelling, and in vitro release pattern of cetirizine hydrochloride, which was selected as a model drug. Materials and Methods: These gelatin and sodium alginate hydrogels were prepared at room temperature through free radical polymerization using glutaraldehyde as a crosslinker. These polymeric composites were used as model systems to envisage various important characterizations. The in vitro release pattern of drug was investigated in three different mediums (phosphate buffer solution of pH 1.2, 5.5, 7.5 whose ionic strength was kept constant). Various structure property relationships that affect its release behavior were determined such as swelling analysis, porosity, solgel analysis, average molecular weight between crosslinks (Mc), solvent interaction parameter (χ), volume fraction of polymer (V 2,s) and diffusion coefficient. The structural, crystallinity, and thermal stability were confirmed using FTIR, XRD, and DSC analysis. Results: These hydrogels showed maximum swelling at pH 1.2. Zero-order, first-order, Higuchi, and Peppas models were applied to demonstrate the release pattern of drug. The release of drug occurred through non-Fickian diffusion or anomalous mechanism. Porosity was found increased with an increase in concentration of both polymers, and porosity decreased when the concentration of the crosslinker was increased. Gel fraction increased with an increase in concentration of SA, Ge, and glutaraldehyde. Conclusion: The prepared pH sensitive hydrogels can be used as a potential carrier for the sustained delivery of cetirizine hydrochloride.