Effects of Drug-Free Pectin Hydrogel Films on Thermal Burn Wounds in Streptozotocin-Induced Diabetic Rats.

This study aims to examine the influence of drug-free pectin hydrogel films on partial-thickness burn wounds using streptozotocin-induced diabetic rats as the animal model. Thirty male Sprague Dawley rats were included in the wound healing study, and scalding water was used to produce wounds in the dorsum region of the rats. Two different formulations of pectin hydrogel films, PH 2.5% and PH 5%, were prepared using a solvent evaporation method. MEBO® (moist exposed burn ointment), a commercial herbal formulation was used as a positive control. The progress of the wound healing was observed and compared between untreated normal rats, untreated diabetic rats, diabetic rats treated with MEBO®, diabetic rats treated with PH 2.5%, and diabetic rats treated with PH 5%. The results showed that diabetic rats treated with PH 5% healed faster than the untreated diabetic rats and diabetic rats treated with PH 2.5%. Interestingly, the diabetic rats treated with PH 5% healed as well as diabetic rats treated with MEBO®, where wounds were healed entirely on day 20. Nevertheless, both PH 2.5% and PH 5% showed a greater zone of inhibition than MEBO® when tested against Staphylococcus aureus.

A revisit to the effects of zinc salt on skin burn wound healing to reflect the risks in current pharmaceutical care.

The lower limit of soluble zinc content that can possibly be applied onto a wounded skin as a healing promoter was not known. This study examined skin wound healing process of rats inflicted by partial thickness thermal burn wound as a function of applied soluble zinc contents (0.1 ml of zinc chloride solution 0.01% (w/w) or 5.0% (w/w)). The size, surface morphology and histological profiles of wound beds of untreated rats and those treated with zinc chloride solutions were characterized. A soluble zinc content as low as 10.5 µg/cm2 of skin negated skin wound healing when compared to the untreated rats. This was alarming as the commercial products currently in the market are formulated with a high level of zinc content. Albeit the zinc salt employed was water-insoluble, a minute fraction of soluble zinc might be available to the treatment sites. This could be partially responsible for the late adverse effects such as pruritis and inflammation reported with calamine/diphenhydramine lotion, medicated shampoo, Olay Complete defense moisturizing lotion and Zineryt® topical solution. The skin irritation was likely a resultant oxidative stress action of soluble zinc, where a small fraction could be adequate to negate the skin homeostasis.[Figure: see text]Key messagesZinc is essentially a cofactor for skin collagen formation.Soluble zinc content as low as 10.5 µg/cm2 of skin irritates skin and negates burn wound healing.Skin irritation of commercial products relates to minute soluble zinc content availability.

In Vitro Drug Dissolution/Permeation Testing of Nanocarriers for Skin Application: a Comprehensive Review.

This review highlights in vitro drug dissolution/permeation methods available for topical and transdermal nanocarriers that have been designed to modulate the propensity of drug release, drug penetration into skin, and permeation into systemic circulation. Presently, a few of USFDA-approved in vitro dissolution/permeation methods are available for skin product testing with no specific application to nanocarriers. Researchers are largely utilizing the in-house dissolution/permeation testing methods of nanocarriers. These drug release and permeation methods are pending to be standardized. Their biorelevance with reference to in vivo plasma concentration-time profiles requires further exploration to enable translation of in vitro data for in vivo or clinical performance prediction.

Students perception of an industry based approach problem based learning (PBL) and their performance in drug delivery courses.

OBJECTIVE: To investigate students perception of an industry based approach problem based learning (PBL) and their performance in drug delivery courses in pharmaceutics. METHODS: PBL was implemented within two drug delivery courses in 2015, in anticipation that the use of formulation or industrial instead of clinical or pharmacy practice based triggers, would open up student interest and understanding towards learning pharmaceutics in relation to industrial pharmacy. Two cohorts were monitored through final year examination results and PBL feedback to evaluate student perception and acceptance of the use of PBL. Previous cohorts were only exposed to conventional tutorials. RESULTS: Both cohorts showed better performance in their final examination results (2015 & 2016) compared to the previous year (2014) when students were only exposed to tutorials. The maximum and average marks obtained were also higher. There was significant difference between the maximum marks for Drug Delivery Systems 2 and the average marks for Drug Delivery Systems 1 with P < 0.05. It was also noted that although the cGPA of student intake for Cohort 2014 is higher than Cohorts 2015 and 2016, the performance of students were better seen in the two latter cohorts. In addition, student feedback showed positive acquiescence towards using PBL as part of the course. CONCLUSIONS: Introduction of PBL in the drug delivery courses has shown to improve student academic performance either directly or indirectly by increasing student's interest and understanding of the subjects taught. It also enhanced student soft skills and confidence. Students were happy with the implementation of PBL which improved their understanding of the subject, enhancing their abilities to think critically and improved their time management abilities.

Microwave modified non-crosslinked pectin films with modulated drug release.

The effects of microwave on drug release properties of pectin films carrying sulfanilamide (SN-P), sulfathiazole (ST-P) and sulfamerazine (SM-P) of high to low aqueous solubilities were investigated. These films were prepared by solvent evaporation technique and treated by microwave at 80 W for 5-40 min. Their profiles of drug dissolution, drug content, matrix interaction and matrix crystallinity were determined by drug dissolution testing, drug content assay, differential scanning calorimetry, X-ray diffractometry and scanning electron microscopy techniques. Microwave induced an increase in matrix amorphousness but lower drug release propensity with a greater retardation extent in SN-P films, following a rise in strength of matrix interaction. A gain in amorphous structure does not necessarily increase the drug release of film. Microwave can possibly retard drug release of pectin film carrying water-soluble drug through modulating its state of matrix interaction.

Characterization of hydroxypropylmethylcellulose films using microwave non-destructive testing technique.

The applicability of microwave non-destructive testing (NDT) technique in characterization of matrix property of pharmaceutical films was investigated. Hydroxypropylmethylcellulose and loratadine were selected as model matrix polymer and drug, respectively. Both blank and drug loaded hydroxypropylmethylcellulose films were prepared using the solvent-evaporation method and were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using microwave NDT technique as well as ultraviolet spectrophotometry, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) techniques. The results indicated that blank hydroxypropylmethylcellulose film exhibited a greater propensity of polymer-polymer interaction at the O-H and C-H domains of the polymer chains upon conditioned at a lower level of relative humidity. In the case of loratadine loaded films, a greater propensity of polymer-polymer and/or drug-polymer interaction via the O-H moiety was mediated in samples conditioned at the lower level of relative humidity, and via the C-H moiety when 50% relative humidity was selected as the condition for sample storage. Apparently, the absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer and/or drug-polymer interaction involving the O-H and C-H moieties. The measurement of microwave NDT test at 8GHz was sensitive to the chemical environment involving O-H moiety while it was greatly governed by the C-H moiety in test conducted at a higher frequency band of microwave. Similar observation was obtained with respect to the profiles of microwave NDT measurements against the state of polymer-polymer and/or drug-polymer interaction of hydroxypropylmethylcellulose films containing chlorpheniramine maleate. The microwave NDT measurement is potentially suitable for use as an apparent indicator of the state of polymer-polymer and drug-polymer interaction of the matrix.