comparison of explanation methods of encapsulation efficacy of hydroquinone in a liposomal system

One of the most important parameters describing the liposomal formulation of hydroquinone is encapsulation efficacy. For the efficacy evaluation of hydroquinone trapped in liposomal structure, there is a need to first separate liposome from the matrix surrounding it

There are various separation techniques; however, in this study, the three techniques of centrifuges with and without washing and dialysis were used

From among the laboratory techniques, an appropriate method is the one that offers responses with a high repeatability

The statistical calculations revealed that encapsulation efficacy with a direct method resulted from a separation via the techniques of dialysis and centrifuge without washing had the highest dispersion with SDs of 6.1 and 8.7, respectively, while the SD value in the technique of centrifuge with washing was 5.2. Through an indirect method, hydroquinone encapsulation efficacy showed the best repeatability with SD values of 2.8 and 2.1 by using the two techniques of centrifuge and centrifuge filtration, respectively

It seems that the treatments leading to the dilution of hydroquinone formulation would result in hydroquinone leakage and a reduction of encapsulation efficacy

It seems that measurement of hydroquinone encapsulation efficacy with an indirect method is a better choice; therefore, a centrifuge technique was utilized to report the mentioned efficacy at a speed of 45000 rcf and duration of 30 min due to having a reasonable price and ease of access?

Analgesic efficacy of aloe Vera and green tea mouthwash after periodontal pocket reduction surgery: a randomized split-mouth clinical trial

Objectives: the aim of this study was to assess the efficacy of aloe vera and green tea mouthwash for reducing pain after periodontal pocket reduction surgery

Methods: this randomized, split-mouth, double-blind, cross-over clinical trial was carried out on 45 patients between 25 and 50 years of age requiring pocket reduction surgery. Patients underwent bilateral surgeries in two sessions. After the first surgery, the patients were randomized to receive either mouthwash or placebo for 10 days; then, each group used the other product for the same time period. The parameters assessed following each procedure were the numeric pain rating scale [NPRS] and number of painkillers taken by patients to alleviate postoperative pain. Also, patients were requested to report side effects, if any, after using the mouthwash

Results: the reported postoperative pain score was significantly lower after using the aloe vera and green tea mouthwash compared to the placebo only in the first postoperative day [P=0.002]. Furthermore, number of analgesic tablets used in the first postoperative day was significantly lower than that in the control group [P=0.007]

Conclusion: our results indicated that patients experienced significantly less early postoperative pain when they used aloe vera and green tea mouthwash. Thus, its application can be recommended to decrease pain after periodontal pocket reduction surgery

UV spectrophotometric determination and validation of hydroquinone in liposome

The method has been developed and validated for the determination of hydroquinone in liposomal formulation. The samples were dissolved in methanol and evaluated in 293 nm. The validation parameters such as linearity, accuracy, precision, specificity, limit of detection [LOD] and limit of quantitation [LOQ] were determined. The calibration curve was linear in 1-50 microg/mL range of hydroquinone analyte with a regression coefficient of 0.9998. This study showed that the liposomal hydroquinone composed of phospholipid [7.8%], cholesterol [1.5%], alpha ketopherol [0.17%] and hydroquinone [0.5%] did not absorb wavelength of 293 nm if it diluted 500 times by methanol. The concentration of hydroquinone reached 10 microg/mL after 500 times of dilution. Furthermore, various validation parameters as per ICH Q2B guideline were tested and found accordingly. The recovery percentages of liposomal hydroquinone were found 102 +/- 0.8, 99 +/- 0.2 and 98 +/- 0.4 for 80%, 100% and 120% respectively. The relative standard deviation values of inter and intra-day precisions were <%2. LOD and LOQ were 0.24 and 0.72 microg/mL respectively

Effects of combined sonodynamic and photodynamic therapies on a colon carcinoma tumor model

Although photodynamic therapy is considered as a noninvasive method, most photosensitizers are susceptible to ultrasound. Therefore, it is expected that the combination of two activation methods might have a synergistic effect. This probable effect has been investigated in this study. This study was conducted on colon carcinoma tumor in Balb/c mice. The tumors were induced by subcutaneous injection of CT26 cells. Ultrasound and light irradiations were performed on tumors 24 hr after injection of liposomal Zn [Il]-phthalocyanine. The treatment efficacy was evaluated using daily measurement of the tumor dimensions. Ten days post treatment, relative tumor volumes of all groups were significantly reduced in comparison with the main control group. The best response was observed when one of the two treatment methods had been applied. The longest doubling time of tumor was related to the treatment group namely photodynamic, sonodynamic and combination technique, while the shortest belonged to the control group. This study showed that liposomal Zn phthalocyanine is both photosensitizer and sonosensitizer. Photodynamic and sonodynamic therapies can be efficient in retarding tumor growth rate. In this study, the combination of two methods didn't show any improvement in therapeutic outcomes. It is predicted that latest results are related to the treatments sequence and could be optimized in the future

[Evaluation of the combined effects of sonodynamic and photodynamic therapies in a colon carcinoma tumor model[CT26]]

Photodynamic therapy is a noninvasive therapeutic method for tumors with a maximum depth 0.5 mm. On the other hand, most photosensitixers are also susceptible to ultrasound waves [the basis of sonodynamic therapy]. Therefore, it is expected that a combination of the two therapeutic methods will increase effectiveness of photodynamic therapies for lower doses of sensitizer and curing deeper tumors. This study evaluates the synergistic effects of photodynamic and sonodynamic therapies. The study was conducted on a colon carcinoma tumor model in Balb/c mice. The colon carcinoma tumors were induced in the mice by subcutaneous injection. Twenty four hours after intraperitoneal injection of Zinc Phthalocyanine liposome as a sensitixer, at first ultrasound irradiation with a known frequency and intensity was performed followed by illumination of the tumor area. Evaluation of the treatment efficacy was done using daily measurement of the tumors and calculation of their relative volumes. Also, all control groups were considered to confirm the effect of each therapeutic option in the study. In the first ten days post treatment, the relative volumes of all groups decreased significantly in comparison with the main control group, but the best response was observed in the photodynamic or sonodynamic therapy groups. The longest doubling time of tumor size was related to groups under photodynamic, sonodynamci and main therapies, and the shortest belonged to the control group. Zinc phthalocyanine lipsome is both a photosensitizer and sonsentisitizer. Photodynamic and sonodynamic therapies can be efficient in retarding tumor growth rate. In this study, combination of the two methods did not cause improved therapeutic outcomes. It is predicted that this result is related to the choice of therapeutic agents and could be optimized in future

Preparation and investigation of poly [N-isopropylacrylamide-acrylamide] membranes in temperature responsive drug delivery

Physiological changes in the body may be utilized as potential triggers for controlled drug delivery. Based on these mechanisms, stimulus-responsive drug delivery has been developed. In this study, a kind of poly [N-isopropylacrylamide-acrylamide] membrane was prepared by radical copolymerization. Changes in swelling ratios and diameters of the membrane were investigated in terms of temperature. On-off regulation of drug permeation through the membrane was then studied at temperatures below and above the phase transition temperature of the membrane. Two drugs, vitamin B[12] and acetaminophen were chosen as models of high and low molecular weights here, respectively. It was indicated that at temperatures below the phase transition temperature of the membrane, copolymer was in a swollen state. Above the phase transition temperature, water was partially expelled from the functional groups of the copolymer. Permeation of high molecular weight drug models such as vitamin B[12] was shown to be much more distinct at temperatures below the phase transition temperature when the copolymer was in a swollen state. At higher temperatures when the copolymer was shrunken, drug permeation through the membrane was substantially decreased. However for acetaminophen, such a big change in drug permeation around the phase transition temperature of the membrane was not observed. According to the pore mechanism of drug transport through hydrogels, permeability of solutes decreased with increasing molecular size. As a result, the relative permeability, around the phase transition temperature of the copolymer, was higher for solutes of high molecular weight

novel composite membrane for ph responsive permeation

In this study, a kind of pH sensitive composite membrane was prepared and drug permeation through it was investigated in terms of pH. Rationale of this study originated from the fact that a pH change which may be a result of a disease state in the body can trigger drug release. Here, a kind of pH sensitive composite membrane containing different nanoparticle [1: 1 n-isopropyl acrylamide [Nipam]: metacrylic acid [Maa]] contents in ethylcellulose was prepared by a casting method. Swelling ratios of these nanoparticles and composite membranes with different particle loadings were determined. Permeation of two different drug models with different hydrophilicity and molecular weights, vitamin B12 [vit B12] and paracetamol, through these membranes was studied in terms of pH. It was seen that swelling ratios of nanoparticles and the composite membranes went up as the particle content increased at each pH. Vit B12 and paracetamol permeation through the membranes in pH value below the pKa was much higher than that at pHs above it, but this difference was much more pronounced for vit B12 compared to paracetamol. Permeation through these membranes showed a sharp sensitivity to pH changes. Nanoparticles in the composite membranes could act as nanovalves due to their sharp swelling/shrinkage around the pKa of Maa. These membranes could be considered as an ideal stimuli-sensitive barrier for modulating drug release with a small change in pH