An improved topical gel was developed which could allow fast release of drug and having appropriate organoleptic (texture) and rheological properties (viscosity). In vitro release of diclofenac potassium from hydrophobically modified hydroxypropyl methyl cellulose (hm-HPMC, 90L grade) based gels (F1, F2 and F3 at 1, 1.5 and 2 % (w/v) concentration, respectively) was compared with conventional hydrophilic hydroxypropyl methylcellulose (HPMC, 50 mPa s) based gels (F4 and F5 at 12 and 15 % (w/v) concentration, respectively). This study was performed in Franz diffusion cell using cellulose dialysis membrane. The hm-HPMC-based gels of higher viscosity release remarkable quantity of the drug in comparison to conventional hydrophilic HPMC-based gels of lower viscosity. So in the drug-release process polymer concentration is more important and a determinant factor compared to viscosity. Texture profile and viscosity of hm-HPMC-based gels were compared with a commercial gel and all the rheological data obtained from the experiments confirm the suitability of these hm-HPMC-based gels for use as a topical drug delivery system. In order to achieve percutaneous penetration of drug, permeation enhancers (n-octanol and propylene glycol) were added in hm-HPMC-based gels. Both enhancers have shown enhancement of drug penetration through rat skin. Propylene glycol at both lower concentration (2 %) and higher concentration (5 %) exhibited a greater increase in the permeation flux as well as more antinociceptive activity than formulations without enhancer or with n-octanol as enhancer.

Antibiotic use is an essential method for the treatment of bacterial infections. In certain cases, antibiotics are not effective because of the distribution problems caused by physiological barriers in the body. Such problems are thought to be minimized by development of sustained release systems which involve implantation of antibiotic loaded polymeric systems directly to the site of infection. In this work, a new composite vancomycin hydrochloride release system based on HPMC microparticles and chitosan/glycerophosphate (Ch/Gp) thermosensitive hydrogel was designed for the aim of local treatment of osteomyelitis. Vancomycin-loaded HPMC microparticles (Van-HPMCs) were prepared by spray drying method. The SEM results showed that these particles had a mean diameter of 1.5-6.4 lm with a narrow size distribution and homogeneous particle production. Their drug encapsulation efficiency was 72.6%. The Van-HPMCs were embedded in an injectable Ch/Gp solution to introduce a composite drug release platform (Van/HPMC-Ch/Gp). In vitro release studies indicated that inclusion of the Van- HPMCs into the Ch/Gp hydrogel caused a reduction in both the release rate and total amount of vancomycin release, which suggests that HPMC microparticles entrapped into the Ch/Gp hydrogels showed more suitable sustained release kinetics for local antibiotics delivery.

Introduction: In recent years, edible films and coatings have received much attention in food packaging. These packaging’s displays suitable film-formation properties such as their biodegradable and carrier of food additive such as antioxidant, antimicrobial, color and nutrients.Materials and Methods: The antioxidant activity (AA) of sage essential oil (EO) in various in vitro model systems was investigated. Physical and AA of Hydroxypropylmethylcellulose (HPMC) film with sage essential oil were also evaluated.Results: In order to determine the AA of sag essential oil with DPPH radical scavenging, b- carotene/linoleic acid bleaching and reducing power assays, IC50 values were 907.7, 454.2 and 1362.42 mg/ml respectively and sag essential oil showed lower AA as compared to BHT. Addition of essential oil to film led to 1.5 times decrease in water vapor (WVP) and 1.7 times decrease in oxygen permeability (OP). Films with essential oil have a lower transparency as compared to films without essential oil as lightness reduced from 95.47 to 90.3. The addition of essential oil resulted in a significantly decrease in tensile strength (3 times) and elastic modulus (2.1 times) but elongation percentage haven’t significant difference (P>0.05) with films without essential oil. Film with sage essential oil showed good protective effects against soyabean oil oxidation as peroxide value of the samples without HPMC film coating, packed by film and film with sag essential oil was 92.7, 85.9 and 66.3 meq O2/kg oil respectively.Conclusion: The WVP and OP of HPMC edible film were improved by the addition of sage essential oil. Also, combination of essential oils into HPMC film is a suitable method for reducing of lipid oxidation.

Background: The goal of the present study was the preparation and evaluation of griseofulvin topical gel as a drug dosage form with appropriate efficacy and stability. Methods: To select the best formulation, formulations with different concentration of carbomer and HPMC were evaluated for their appearance. Then evaluated for physicochemical characteristics such as rheologic behavior, viscosity, stability and drug release. Results: The result showed that the topical gel of griseofulvin prepared with Carbomer 0.5% and HPMC2.5% had good chemical stability, viscosity and drug release. The evaluation of the kinetic of drug release indicated that the formulations containing Carbomer 0.5% and HPMC 2.5% followed zero order release and liner Wagner, respectively. Rheological data showed that while HPMC gel shows a very mild plastic behavior, Carbomer based gels behave very significantly as a thixotropic pseudo plastic gel. Discussion: Rheological behavior can affect the physicochemical and pharmacological aspects of the drug and plastic behavior of carbomer gel made it suitable for topical application. Although clinical research is necessary for Confirm the effectiveness but as a result, topical griseofulvin in a suitable formulation showed good drug release and efficacy.

Introduction: The skin is considered the first barrier against the penetration of laser light into the body, which causes limitations in imaging or treatment with laser light. The constituents of the skin, which are mainly proteins, lipids, interstitial water, and blood vessels, cause severe light scattering and limit the penetration of light into the deep tissues. This limitation causes the lack of access to structural information and tissue constituents by light and a decrease in the resolution of optical imaging. In this study, using semi-natural HPMC polymer, sorbitol, coconut oil and Tween 20 (called CSC1 and CSC2 for short), the optical parameters of the skin tissue sample were determined by the diffuse reflection spectrum (DRS) method. Research method: DRS was used to obtain the reflection and transmission spectra of the tissue. Then, by using the obtained values and placing them in the Kramers-Kronig relationship, the refractive index can be obtained before and after applying optical clearing agent. Also, other optical parameters such as absorption coefficient, total attenuation coefficient and diffusion coefficient have been calculated from reflection and transmission spectra. Findings: The effect of using optical clearing agent (CSC1, CSC2) on variation of optical properties of sample (refractive index, absorption coefficient, and diffusion coefficient) are measured. Conclusion: The results show that the semi-natural HPMC polymer, which played a role in maintaining the structure of the solution, was effective. Therefore, it can be concluded that the CSC2 could better clear the sample, and it improves the optical depth.

Several studies have been shown that surfactants are able to increase release rate of drugs from HPMC matrices. The present study investigates the effects of various surfactants )nonionic surfactants e.g. Tween 80 with HLB=15 and Arlacel60 with HLB=4.7, sodium lauryl sulphate as an anionic surfactant and cetyl trimethyl ammonium bromide as a cationic surfactant) with different concentrations ranging from 0-10% w/w on the release rate of propranolol hydrochloride from HPMC matrices. The results showed that an increase in the concentration of the surfactant with opposite charge to the drug resulted in a reduction in the release rate of propranolol from HPMC matrices. It was also found that the surfactant with the same charge as the drug had not considerable effect on the release rate of propranolol. The use of nonionic surfactant with high HLB caused an increase in the release rate of the drug, whereas using the low HLB. surfactant produced a reduction in release rate. The increase in release rate of the drug in presence of surfactant is attributed to an increase in wettability of tablet surfaces, reduction in surface tension, micellar solubilization and increase in drug solubility. The reduction in release rate of the drug could be due to the formation of insoluble complex between the drug of gel layer around matrix and lipophilicity of the matrix surfaces. Studies on the release kinetic of the drug from HPMC matrices showed that both diffusion and erosion mechanisms are responsible for the release of propranolol.

Controlled drug release is vital for sustaining the appropriate blood levels. This necessitates a thorough study of drug release profiles. In this study quantitative relationships between chemical structure of drugs and their release from HPMC E4M were investigated using QSPR (Quantitative Structure Property Relationship) technique. To this end, matrices containing 100 mg of the polymer and 100 mg of drug were prepared using a constant pressure for 12 drugs from different chemical group and the release profiles were investigated at pH=6.8. Release parameters consisted of drug release rate constants calculated from various kinetic models of zero order, first order, Peppas, Higuchi and Weibull as well as dissolution efficiency, the amount of drug released within the first 8h and the time required for the release of 50% of drugs. Structural parameters were obtained from Molecular mechanics, Quantum mechanics, graph theoretical software packages and ACD log D suit. Stepwise regression analysis was used in Minitab statistical software in order to establish statistically significant relationships between each release parameter and structural descriptors. The resulting equations revealed that increasing the molecular size leads to decreased release rate and efficiency from HPMC E4M matrices. However the drug release rate increased with the increase of the drug solubility.