In present investigation new formulations of Sodium Alginate/Acrylic acid hydrogels with high porous structure were synthesized by free radical polymerization technique for the controlled drug delivery of analgesic agent to colon. Many structural parameters like molecular weight between crosslinks (M c), crosslink density (M r), volume interaction parameter (v 2,s), Flory Huggins water interaction parameter and diffusion coefficient (Q) were calculated. Water uptake studies was conducted in different USP phosphate buffer solutions. All samples showed higher swelling ratio with increasing pH values because of ionization of carboxylic groups at higher pH values. Porosity and gel fraction of all the samples were calculated. New selected samples were loaded with the model drug (diclofenac potassium).The amount of drug loaded and released was determined and it was found that all the samples showed higher release of drug at higher pH values. Release of diclofenac potassium was found to be dependent on the ratio of sodium alginate/acrylic acid, EGDMA and pH of the medium. Experimental data was fitted to various model equations and corresponding parameters were calculated to study the release mechanism. The Structural, Morphological and Thermal Properties of interpenetrating hydrogels were studied by FTIR, XRD, DSC, and SEM.

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.

Conventional dosage forms provide a sharp increase in plasma drug levels that falls below the therapeutic range after short interval of time until the re-administration of drug. There is a need of such dosage forms which provide not only sustained drug delivery but also reduce the plasma drug levels fluctuations. Microspheres used in drug delivery systems due to their ability to sustain the drug release, their biodegradability and compatibility and targeted drug delivery. In this review different types of microspheres their methods for the preparation with different hydrophilic and hydrophobic polymers, drug loading capacities will be discussed. Different characterizations like SEM, FTIR, XRD, DSC, rheological properties and invitro drug release are successfully described.

Dear sir, The on-going discussion on fixed dosing or personalized dosing of pembrolizumab has created great chaos among the patients of metastatic non-small cell lung cancer (NSCLC). Below mentioned are few points in this regard, Delta variant has affected economies of Asian countries in multiple ways. Personalized and six week dosing of pembrolizumab can be beneficial in this regard. A study conducted by DANIAL A. GOLDSTEIN and co-authors, compared fixed dosing of pembrolizumab with personalized dosing. They have concluded the result that personalized dosing can save upto 24.0% of annual savings in US that is equal to 0.825 billion dollar [1]. These results are supported by another study in which Q6W dosing of pembrolizumab is compared with Q3W dosing. The study states that 400 mg Q6W dosing of pembrolizumab leads to results that are very similar to 200mg Q3W dosing regimen [2]. Another study proposed weight based as well as six weeks dosing of pembrolizumab for the ease of cancer patients [3]. As pembrolizumab is approved for patients with stage III resected melanoma therefore delaying its therapy may have similar effects on overall survival [4]. Keeping all these point in view we would like to suggest that it would be better if doctors from now onwards suggest Q6W dosing of pembrolizumab instead of Q3W dosing as well as personalized dosing should be promoted as compared to fixed dosing as this well help in lowering down the financial as well as health burden on patients with metastatic non-small cell lung cancer (NSCLC). Continue...