Thermoanalytical characterization of clindamycin-loaded intravitreal implants prepared by hot melt extrusion

Selective Delivery of Clindamycin Using a Combination of Bacterially Sensitive Microparticle and Separable Effervescent Microarray Patch on Bacteria Causing Diabetic Foot Infection

INTRODUCTION

Diabetic foot infection (DFI) is one of the complications of diabetes mellitus. Clindamycin (CLY) is one of the antibiotics recommended to treat DFI, but CLY given orally and intravenously still causes many side effects.

METHODS

In this study, we encapsulated CLY in a bacteria sensitive microparticle system (MP-CLY) using polycaprolactone (PCL) polymer. MP-CLY was then delivered in a separable effervescent microarray patch (MP-CLY-SEMAP), which has the ability to separate between the needle layer and separable layer due to the formation of air bubbles when interacting with interstitial fluid in the skin.

RESULT

The characterization results of MP-CLY proved that CLY was encapsulated in large amounts as the amount of PCL polymer used increased, and there was no change in the chemical structure of CLY. In vitro release test results showed increased CLY release in media cultured with Staphylococcus aureus bacteria and showed controlled release. The characterization results of MPCLY-SEMAP showed that the developed formula has optimal mechanical and penetration capabilities and can separate in 56 ± 5.099 s. An ex vivo dermatokinetic test on a bacterially infected skin model showed an improvement of CLY dermatokinetic profile from MP-CLY SEMAP and a decrease in bacterial viability by 99.99%.

CONCLUSION

This research offers proof of concept demonstrating the improved dermatokinetic profile of CLY encapsulated in a bacteria sensitive MP form and delivered via MP-CLY-SEMAP. The results of this research can be developed for future research by testing MP-CLY-SEMAP in vivo in appropriate animal models.

Injectable Platelet-Rich Fibrin as a Drug Carrier Increases the Antibacterial Susceptibility of Antibiotic—Clindamycin Phosphate

The aim of this study was to investigate the change in clindamycin phosphate antibacterial properties against Gram-positive bacteria using the platelet-rich fibrin as a carrier matrix, and evaluate the changes in the antibiotic within the matrix. The antibacterial properties of CLP and its combination with PRF were tested in a microdilution test against reference cultures and clinical isolates of Staphylococcus aureus (S. aureus) or Staphylococcus epidermidis (S. epidermidis). Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analysis was done to evaluate the changes in the PRF_CLP matrix. Release kinetics of CLP was defined with ultra-performance liquid chromatography (UPLC). According to FTIR data, the use of PRF as a carrier for CLP ensured the structural changes in the CLP toward a more active form of clindamycin. A significant decrease in minimal bactericidal concentration values (from 1000 µg/mL to 62 µg/mL) against reference cultures and clinical isolates of S. aureus and S. epidermidis was observed for the CLP and PRF samples if compared to pure CLP solution. In vitro cell viability tests showed that PRF and PRF with CLP have higher cell viability than 70% after 24 h and 48 h time points. This article indicates that CLP in combination with PRF showed higher antibacterial activity against S. aureus and S. epidermidis compared to pure CLP solution. This modified PRF could be used as a novel method to increase drug delivery and efficacy, and to reduce the risk of postoperative infection.

Solid Polymeric Nanoparticles of Albendazole: Synthesis, Physico-Chemical Characterization and Biological Activity

Albendazole is a benzimidazole derivative with documented antitumor activity and low toxicity to healthy cells. The major disadvantage in terms of clinical use is its low aqueous solubility which limits its bioavailability. Albendazole was incorporated into stable and homogeneous polyurethane structures with the aim of obtaining an improved drug delivery system model. Spectral and thermal analysis was used to investigate the encapsulation process and confirmed the presence of albendazole inside the nanoparticles. The in vitro anticancer properties of albendazole encapsulated in polyurethane structures versus the un-encapsulated compound were tested on two breast cancer cell lines, MCF-7 and MDA-MB-231, in terms of cellular viability and apoptosis induction. The study showed that the encapsulation process enhanced the antitumor activity of albendazole on the MCF-7 and MDA-MB-23 breast cancer lines. The cytotoxic activity manifested in a concentration-dependent manner and was accompanied by changes in cell morphology and nuclear fragmentation.

Formulation Optimization of Selective Laser Sintering 3D-Printed Tablets of Clindamycin Palmitate Hydrochloride by Response Surface Methodology

The aims of the current study were to develop and evaluate clindamycin palmitate hydrochloride (CPH) 3D-printed tablets (printlets) manufactured by selective laser sintering (SLS). Optimization of the formulation was performed by studying the effect of formulation and process factors on critical quality attributes of the printlets. The independent factors studied were laser scanning speed, microcrystalline cellulose (MCC), and lactose monohydrate (LMH) concentration. The responses measured were printlets weight, hardness, disintegration time (DT), and dissolution in 30 min. The printlets were characterized for content uniformity, chemical interactions, crystallinity, drug distribution, morphology, and porosity. The laser scanning speed showed statistically significant effects on all the studied dependent responses (p < 0.05). MCC showed statistically significant effects on hardness, DT, and dissolution (p < 0.05), while LMH showed statistically significant effect on hardness and dissolution (p < 0.05). The model was validated by an independent formulation, and empirical values were in close agreement with model-predicted values. X-ray powder diffraction and differential scanning calorimetry data suggested a decrease in crystallinity of the LMH in the printlets. X-ray micro-CT scanning showed porous microstructure of the printlets with a porosity 24.4% and 31.1% for the printlets printed at 200 and 300 mm/s laser speed, respectively. In summary, the SLS method provides an opportunity to fabricate customized dosage forms as per patients' need.

Investigation of Drug-Polymer Compatibility Using Chemometric-Assisted UV-Spectrophotometry

A simple chemometric-assisted UV-spectrophotometric method was used to study the compatibility of clindamycin hydrochloride (HC1) with two commonly used natural controlled-release polymers, alginate (Ag) and chitosan (Ch). Standard mixtures containing 1:1, 1:2, and 1:0.5 w/w drug-polymer ratios were prepared and UV scanned. A calibration model was developed with partial least square (PLS) regression analysis for each polymer separately. Then, test mixtures containing 1:1 w/w drug-polymer ratios with different sets of drug concentrations were prepared. These were UV scanned initially and after three and seven days of storage at 25 °C. Using the calibration model, the drug recovery percent was estimated and a decrease in concentration of 10% or more from initial concentration was considered to indicate instability. PLS models with PC3 (for Ag) and PC2 (for Ch) showed a good correlation between actual and found values with root mean square error of cross validation (RMSECV) of 0.00284 and 0.01228, and calibration coefficient (R²) values of 0.996 and 0.942, respectively. The average drug recovery percent after three and seven days was 98.1 ± 2.9 and 95.4 ± 4.0 (for Ag), and 97.3 ± 2.1 and 91.4 ± 3.8 (for Ch), which suggests more drug compatibility with an Ag than a Ch polymer. Conventional techniques including DSC, XRD, FTIR, and in vitro minimum inhibitory concentration (MIC) for (1:1) drug-polymer mixtures were also performed to confirm clindamycin compatibility with Ag and Ch polymers.