Development and evaluation of a pH-responsive Mimosa pudica seed mucilage/ß- cyclodextrin-co-poly(methacrylate) hydrogel for controlled drug delivery: In vitro and in vivo assessment.

In this comprehensive investigation, a novel pH-responsive hydrogel system comprising mimosa seed mucilage (MSM), ß-cyclodextrin (ß-CD), and methacrylic acid (MAA) was developed via free radical polymerization technique to promote controlled drug delivery. The hydrogel synthesis involved strategic variations in polymer, monomer, and crosslinker content in fine-tuning its drug-release properties. The resultant hydrogel exhibited remarkable pH sensitivity, selectively liberating the model drug (Capecitabine = CAP) under basic conditions while significantly reducing release in an acidic environment. Morphological, thermal, and structural analyses proved that CAP has a porous texture, high stability, and an amorphous nature. In vitro drug release experiments showcased a sustained and controlled release profile. Optimum release (85.33 %) results were recorded over 24 h at pH 7.4 in the case of MMB9. Pharmacokinetic evaluation in healthy male rabbits confirmed bioavailability enhancement and sustained release capabilities. Furthermore, rigorous toxicity evaluations and histopathological analyses ensured the safety and biocompatibility of the hydrogel. This pH-triggered drug delivery system can be a promising carrier system for drugs involving frequent administrations.

Development and Evaluation of Sodium Alginate/Carbopol 934P-Co-Poly (Methacrylate) Hydrogels for Localized Drug Delivery.

This research was carried out to create a pH-responsive polymeric system for the targeted drug delivery of Diloxanide furoate. It relied on sodium alginate (Na-Alg) and Carbopol 934P as building blocks. Using an aqueous free radical polymerization method, SCH1-SCH12 was created with varying polymer, MAA, and MBA input ratios. Positive outcomes were seen in the swelling and release profiles at higher pH levels. Hydrogel formation, as well as component compatibility, thermal stability, and Diloxanide furoate loading, were all validated by instrumental characterization. A drug loading percentage of 83.56% was determined, with the swelling reaching 743.19%. For the formulation with MBA, the gel fraction was 94.58%. The release of diloxanide furoate increased to 91.77% at neutral pH. The formulation containing Carbopol 934P provided the highest mucoadhesion force (3993.42 dynes/cm2). The created hydrogel has been shown to be biocompatible by toxicological testing of the network. Based on the findings, the created polymeric nexus proved promising for pH-dependent localized and regulated delivery of Diloxanide furoate.

Smart pH-responsive Co-polymeric Hydrogels for Controlled Delivery of Capecitabine: Fabrication, Optimization and In Vivo Toxicology Screening.

BACKGROUND: Despite exhibiting promising anticancer potential, the clinical significance of capecitabine (a potent prodrug of 5-fluorouracil used for the treatment of colorectal cancer) is limited owing to its acidic and enzymatic hydrolysis, lower absorption following the oral administration, poor bioavailability, short plasma half-life, and poor patient compliance. OBJECTIVES: The present study was aimed to fabricate the capecitabine as a smart pH-responsive hydrogel network to efficiently facilitate its oral delivery while shielding its stability in the gastric media. METHODS: The smart pH-sensitive HP-ß-CD/agarose-g-poly(MAA) hydrogel network was developed using an aqueous free radical polymerization technique. The developed hydrogels were characterized for drug-loading efficiency, structural and compositional features, thermal stability, swelling behaviour, morphology, physical form, and release kinetics. The pH-responsive behaviour of developed hydrogels was established by conducting the swelling and release behaviour at different pH values (1.2 and 7.4), demonstrating significantly higher swelling and release at pH 7.4 as compared with pH 1.2. The capecitabine-loaded hydrogels were also screened for acute oral toxicity in animals by analysing the body weight, water and food intake, dermal toxicity, ocular toxicity, biochemical analysis, and histological examination. RESULTS: The characteristic evaluations revealed that capecitabine (anticancer agent) was successfully loaded into the hydrogel network. The range of capecitabine loading was from 71.22% to 90.12%. An interesting feature of hydrogel was its pH-responsive behaviour which triggers release at basic pH (94.25%). Optimum swelling (95%)was seen at pH 7.4. Based upon regression coefficient R2(0.96 - 0.99) the best-fit model was zero-order. The extensive toxicity evaluations evidenced a good safety profile with no signs of oral, dermal, or ocular toxicities, as well as no variations in blood parameters and histology of vital organs. CONCLUSION: Our findings conclusively evinced that the developed hydrogel exhibited excellent pharmaceutical and therapeutic potential and thus can be employed as a pH-responsive system for the controlled delivery of anticancer agents.

Microbiological quality control of some non-sterile preparations commonly used in Pakistan.

The quality of medicines in some developing countries including Pakistan is not very satisfactory regarding safety and efficacy. In addition to sterile preparations, the microbial contamination of non sterile preparations should also be monitored according to USP microbial limits for these preparations. This study was designed to check the microbial quality of some commonly used non-sterile preparations available in Pakistan. Total 133 samples containing national and multinational brands of different dosage forms were collected from retail setups of Sargodha, Khushab and Chakwal cities. The total aerobic bacterial count and fungal contamination was tested by pour plate method. The absence of objectionable microorganisms was confirmed by using selective media, biochemical testing and microscopy. Bioburden of these preparations was also tested after a storage period of six months. The bio burden varied among all the selected non-sterile preparations whether of local or multinational brands. The highest load was observed in syrups, among which syrup number 1 showed maximum aerobic count (8.4×106). Lowest count was observed in tablets, among which tablet preparation number 1 contained 1.5×103aerobic bacteria. Creams and capsules produced no recovered bacteria. The fungal contaminants were also observed in all dosage forms except tablets. The isolated organisms included Gramnegative bacteria which contained objectionable ones such as Salmonella, Shigella, Pseudomonas and E.coli and some airborne moulds including Aspergillus spp., Penicillium spp., Fusarium spp. and Acremonium spp. Several measures such as GMPs, monitoring programs and SOPs should be followed by the pharmaceutical companies to reduce the microbial contamination level in the non sterile preparations. The regulatory agencies have to implement strict analysis strategy to check the microbial quality of the medicines before their release for sale in the market.