Does prophylactic decompression of distal nerves following nerve repair improve functional recovery? A systematic review.

BACKGROUND: Peripheral nerve injuries are burdensome on healthcare systems, individuals and society as a whole. The current standard of treatment for neurotmesis is primary neurorrhaphy or nerve grafting. However, several patients do not recover their full function. There has been a suggestion that primary distal neurolysis at common entrapment sites maximises surgical outcomes; however, no guidelines exist on this practice. This scoping review aims to ascertain the existing evidence on prophylactic distal decompression of peripheral nerves following repair. METHODS: A literature search was performed using Ovid Medline, PubMed, Embase and Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews for studies published in the past 50 years. Studies were screened using a selection criteria and study quality was assessed using standardised tools. Furthermore, thematic content analysis was performed. RESULTS: Six studies were eligible for inclusion after screening; all studies were retrospective and at most level 3 evidence. No studies were designed specifically to assess the efficacy of distal neurolysis following proximal repair, thus no comparative data with control cohorts are available. All studies that recommended distal decompression of proximally repaired nerves based their conclusions on cases observed by the authors in practice or from theories on nerve regeneration. CONCLUSIONS: This systematic review suggests that the evidence on the role of immediate distal neurolysis in primary neurorrhaphy is inadequate. Recommendations are limited by the lack of large-scale and generalisable data. Further research is needed with definitive objective outcomes and patient-related outcome measures.

Global Forum of Cancer Surgeons: Cancer Surgery During the COVID-19 Pandemic: Impact and Lessons Learned.

BACKGROUND: The purpose of this article is to summarize the opinions of the surgical oncology leaders from the Global Forum of Cancer Surgeons (GFCS) about the global impact of COVID-19 pandemic on cancer surgery. METHODS: A panel session (virtual) was held at the annual Society of Surgical Oncology 2021 International Conference on Surgical Cancer Care to address the impact of COVID-19 on cancer surgery globally. Following the virtual meeting, a questionnaire was sent to all the leaders to gather additional opinions. The input obtained from all the leaders was collated and analyzed to understand how cancer surgeons from across the world adapted in real-time to the impact of COVID-19 pandemic. RESULTS: The surgical oncology leaders noted that the COVID-19 pandemic led to severe disruptions in surgical cancer care across all domains of clinical care, education, and research. Several new changes/protocols associated with increased costs were implemented to deliver safe care. Leaders also noted that preexisting disparities in care were exacerbated, and the pandemic had a detrimental effect on well-being and financial status. CONCLUSIONS: The COVID-19 pandemic has led to severe disruptions in surgical cancer care globally. Leaders of the GFCS opined that new strategies need to be implemented to prepare for any future catastrophic events based on the lessons learned from the current events. The GFCS will embark on developing such a roadmap to ensure that surgical cancer care is preserved in the future regardless of any catastrophic global events.

Evaluation of the frequency and pattern of local recurrence following intersphincteric resection for ultra-low rectal cancer.

INTRODUCTION: Abdomino-perineal resection has been the standard treatment for rectal tumors located ≤5cm from the anal verge. Recently, intersphincteric resection became a valid option which preserves the bowel continuity with better functional outcome. AIM: Is to evaluate the oncological and functional outcome alongside the associated surgical morbidity in patients with T1-3 rectal cancer, who underwent intersphincteric resection (ISR). PATIENTS & METHODS: Between the years 2006 and 2011, 55 patients with invasive rectal adenocarcinoma, T1-3 lesions, located 2-5cm from the anal verge underwent ISR with total mesorectal excision. When inevitable, complete. ISR was performed, otherwise partial ISR was done. All T3 patients underwent total meso-rectal excision (TME) while some had lateral lymph node dissection (LND) with concomitant pelvic autonomic nerve preservation (PANP). RESULTS: Among the 55 patients, 21 (38.1%) patients were T1-2 and 34 (61.9%) patients were T3. The tumor location range was 0-5cm from the anal verge (median 2.3cm). Partial or complete ISR was done for 35 (63.6%) and 20 (36.4%), respectively. Patients were followed for a median of 1.5 years (range 1-4.6 years). The 3 year local recurrence and distant metastasis free rates were 85.2% and 85.6%, respectively. All the 3 local recurrences occurred in T3 patients group, and had positive circumferential resection margins. Overall 3-year disease-free survival was 82.6%; while the overall 3-year survival was 88.7%. CONCLUSION: Intersphincteric resection with TME does not affect the local recurrence or overall survival rate in early rectal cancer T1-2 & 3, with preservation of bowel continuity and better life quality.

Pre-prosthetic surgical alterations in maxillectomy to enhance the prosthetic prognoses as part of rehabilitation of oral cancer patient.

OBJECTIVES: After maxillectomy, prosthetic restoration of the resulting defect is an essential step because it signals the beginning of patient's rehabilitation. The obturator used to restore the defect should be comfortable, restore adequate speech, deglutition, mastication, and be cosmetically acceptable, success will depend on the size and location of the defect and the quantity and integrity of the remaining structures, in addition to pre-prosthetic surgical preparation of defect site. Preoperative cooperation between the oncologist surgeon and the maxillofacial surgeon may allow obturation of a resultant defect by preservation of the premaxilla or the tuberosity on the defect side and maintaining the alveolar bone or teeth adjacent to the defect. This study evaluates the importance of pre-prosthetic surgical alterations at the time maxillectomy on the enhancement of the prosthetic prognoses as part of the rehabilitation of oral cancer patient. STUDY DESIGN: The study was carried out between 2003- 2008, on 66 cancer patients(41 male-25 female) age ranged from 33 to 72 years, at National Cancer Institute, Cairo University, whom underwent maxillectomy surgery to remove malignant tumor as a part of cancer treatment. Patients were divided in two groups. Group A: Resection of maxilla followed by preprosthetic surgical preparation. Twenty-four cancer patients (13 male - 11 female). Group B: Resection of maxilla without any preprosthetic surgical preparation. Forty-two cancer patients (28 male-14 female). RESULTS: Outcome variables measured included facial contour and aesthetic results, speech understandability, ability to eat solid foods, oronasal separation, socializing outside the home, and return-to-work status. Flap success and donor site morbidity were also studied. CONCLUSIONS: To improve the prosthetic restoration of maxillary defect resulting maxillary resection as part treatment of maxillofacial tumor depends on the close cooperation between prosthodontist and surgeon, by combination of pre-prosthetic surgery during maxillectomy and prosthodontic technique.

Passive all-optical polarization switch, binary logic gates, and digital processor.

We introduce the passive all-optical polarization switch, which modulates light with light. That switch is used to construct all the binary logic gates of two or more inputs. We discuss the design concepts and the operation of the AND, OR, NAND, and NOR gates as examples. The rest of the 16 logic gates are similarly designed. Cascading of such gates is straightforward as we show and discuss. Cascading in itself does not require a power source, but feedback at this stage of development does. The design and operation of an SR Latch is presented as one of the popular basic sequential devices used for memory cells. That completes the essential components of an all-optical polarization digital processor. The speed of such devices is well above 10 GHz for bulk implementations and is much higher for chip-size implementations. In addition, the presented devices do have the four essential characteristics previously thought unique to the microelectronic ones.

Phenylpropanoids from the stem bark of Jacaranda mimosaefolia.

Two new compounds: 2-(3',4'-dihydroxyphenyl) ethyl-3-O-α-L-rhamnopyranosyl-4-O-p-hydroxyphenylacetyl-6-O-caffeoyl-ß-D-glucopyranoside and 2-(3',4'-dihydroxyphenyl) ethyl-3-O-α-L-rhamnopyranosyl-4-O-piperidine-3-carboxylic acid-6-O-caffeoyl-ß-D-glucopyranoside were isolated from the stem bark of Jacaranda mimosaefolia. In addition, the known compounds lupeol, betulinaldehyde, terminic acid, betulinic acid, maslinic acid, ß-sitosterol glucoside and isoacteoside were isolated and identified.

Autologous melanocyte-keratinocyte suspension in the treatment of vitiligo.

BACKGROUND: In stable vitiligo, several techniques of autologous transplantation of melanocytes are used. Autologous melanocyte transplantation of non-cultured melanocytes is one of those techniques with variable reported outcomes. OBJECTIVE: The objective of this study was to evaluate the response to autologous melanocyte-keratinocytes suspension transplantation in cases of stable vitiligo. METHODS: A total of 25 cases of vitiligo were treated by autologous melanocyte-keratinocytes suspension transplantation. After 6-17 months, patients' response was evaluated according to the extent of pigmentation (excellent 90-100%, good 50-89%, fair 20-49% and poor response <20%). RESULTS: Of the 25 patients treated, 22 continued the follow-up period. Five (23%) patients showed excellent response, 7 (32%) good, 6 (27%) fair and 4(18%) showed poor response. CONCLUSION: Unlike transplantation of cultured melanocytes, which requires experience in culture technique, autologous melanocyte-keratinocytes suspension transplantation is an easy economic technique, which may be used in resistant areas of stable vitiligo.

Single-angle-of-incidence ellipsometry.

We introduce single angle-of-incidence (SAI) ellipsometry [U.S. patent application 20070024850 (14 July 2006)] as a technique to completely identify, i.e., totally characterize, film-substrate systems. We show that only one measurement of the ellipsometric function rho at one angle of incidence and one wavelength is totally sufficient to determine the optical constant of the film N1, its thickness d, and the substrate's optical constant N2. Obviously, it is also sufficient for characterizing only the film, determining N1 and d, and for characterizing only the substrate, determining N2 and d, as well as for characterizing only bare substrates. An inverse genetic algorithm (IGA) for complete identification is presented that is based on a physical condition of the transparent-film-absorbing-substrate system . This IGA is used to identify the film-substrate system in four separate cases. We show that removing the film thickness from the fitness function of the genetic algorithm and using the defined optimum population size to characterize the film reduces the computational effort from 20,000 to 69 fitness-function calculations; the number of calculations to characterize an absorbing layer is reduced from 80,000 to 180. This is a very significant reduction and is very welcome in real-time applications. An error analysis is presented that shows that the IGA is resilient to, not affected by, random experimental errors and that it gives very good results in the presence of both random and systematic errors of the ellipsometer system. Experimental results are given that also prove the robustness, stability, and high accuracy of the method. We present data only for the SiO2-Si film-substrate system, but the IGA works for any film-substrate system, physical or not.

Preparation, characterization and optimization of probucol self-emulsified drug delivery system to enhance solubility and dissolution.

The main purposes of this work were to prepare, characterize and optimize a self-emulsified drug delivery system of probucol (PBSEDDS) with enhanced dissolution and better chance for oral absorption. The methods included determination of the solubility of probucol in different oils, surfactants and co-surfactants using saturation solubility method and HPLC for drug analysis. The ingredients showing high drug solubility were used to prepare PBSEDDS after being tested for physical and chemical compatibility with the drug using DSC and FTIR. The prepared formulations were evaluated for droplet size, turbidity, spontaneity of emulsification and dissolution in water. Optimization was performed using a three-factor, three-level Box-Behnken experimental design. The results showed high drug solubility and compatibility with soybean oil (solvent), Labrafil M1944CS (surfactant) and Capmul MCM-C8 (cosurfactant). Oil to surfactant/co-surfactant ratio showed large influence on the characteristics of PBSEDDS. Several fold improvement of drug dissolution was observed compared to drug solution in soybean oil alone. Optimization study showed that observed and predicted values of cumulative percent drug dissolution after 60 min were in reasonable agreement. The experimental design applied helped in understanding the effects and the interaction effects between the independent factors. The prepared PBSEDDS may have the potential to enhance the therapeutic bioavailability of probucol.

Using factorial design to improve the solubility and in-vitro dissolution of nimesulide hydrophilic polymer binary systems.

The aim of the present study was to use factorial design to enhance the dissolution rate of nimesulide using solid binary systems with the hydrophilic carriers D-mannitol and polyethylene glycol (PEG 4000). Two-factor full factorial design was employed to investigate the effects of the drug/carrier ratio (X(1), 10 and 20%) and the method of　preparation (X(2), physical or co-melted mixture) on　the percent drug release after 60 min (Y(1)). Drugcarrier co-melted mixtures were prepared by melting the carriers D-mannitol or PEG with the drug. For physical mixtures, the drug and carrier were mixed thoroughly in a mortar until a homogeneous mixture was obtained. Drug-carrier interactions were investigated by differential scanning calorimetry (DSC). All prepared mixtures were filled in hard gelatin capsules, size 0, and then their dissolution rate was tested. The results showed an increase in the solubility of the drug with increasing polymer concentrations. Thermal analysis revealed no notable differences regarding thermal events of nimesulide, D-mannitol, PEG 4000, and their physical or comelted mixtures. The percent drug released after 60 min was 29.5% for nimesulide alone, 37.14 and 32.0% for a PEG/Physical mixture with a 10 or 20% drug/polymer ratio, and 69.7 and 53.1% for a PEG/Co-melted mixture with the same ratios. For nimesulide/D-mannitol, this percent drug released was 33.57 and 29.6% for a physical mixture and 63.13 and 48.04% for a co-melted mixture. Formulations with PEG showed an increase in solubility as well as dissolution in comparison to those prepared with D-mannitol. Factorial design was successfully used to optimize the dissolution rate of nimesulide. The chosen polymers caused a notable increase in drug solubility and co-melted formulations generally showed a higher dissolution than those prepared with physical mixtures.

Ex vivo mucoadhesion and in vivo bioavailability assessment and correlation of ketoprofen tablet dosage forms containing bioadhesives.

The purposes of this study were to assess the mucoadhesion and bioavailability and their correlation for ketoprofen tablet dosage forms (F1-F6) containing polycarbophil (PC), sodium carboxymethylcellulose (Na CMC) as bioadhesives, Avicel pH 101 as direct compressible tablet vehicle or mixtures of these, and non compressible vehicles such as lactose and starch. For mucoadhesion assessment, we used sheep gastric mucosa and for bioavailability we used six human volunteers in an open randomized seven-way crossover study. Young's modulus (YM) and relative bioavailability (RB) parameters were used for evaluation of mucoadhesion and bioavailability, respectively. The results indicated that F2 containing Na CMC (72.5%) showed the highest value of YM (7.6 +/- 0.76 pascals) and 119.4 +/- 3.2% for RB. Decreasing the amount of Na CMC to 10% in F3 and F6 decreased the values of YM and RB to 1.4 +/- 0.08 and 84 +/- 2.05 in F3, 4.6 +/- 0.43 and 114.7 +/- 2.46 in F6, respectively. The highest RB (152.3 +/- 2.56) was observed in F5 containing starch and Avicel pH 101. This formulation showed 6 +/- 0.87 for YM. F4 containing PC (10%) showed 5.1 +/- 0.43 and 74.15 +/- 1.98 for YM and RB respectively. The lowest value of YM was observed in F1 containing Avicel pH 101 (0.27 +/- 0.01) which also showed low RB (93.3 +/- 2.3). In conclusion, formulations containing bioadhesives and/or starch in high concentration showed high values of YM and RB which indicate good correlation between mucoadhesion and bioavailability. Bioadhesives may show a high potential to improve bioavailability and therapeutic efficacy of ketoprofen in tablet dosage forms.

Thin-film coatings--a transmission ellipsometric function approach: I. Nonnegative transmission systems, polarization devices, coatings, and closed-form design formulas.

The transmission ellipsometric function (TEF) of a film-substrate system relates the polarization change, upon transmission, of an electromagnetic wave obliquely incident on, and transmitted through, a film-substrate system. The behavior of the TEF depends on the category of the film-substrate system: negative, zero, or positive. The category is determined by the sign of [equation in text]: negative for a negative film-substrate system, zero for a zero system, and positive for a positive system. We discuss the behavior of the TEFs of the two transparent nonnegative film-substrate systems, zero and positive. We describe the TEF as two successive transformations and analyze its behavior as the angle of incidence and film thickness of the film-substrate system are changed. We use the constant-angle-of-incidence contours and constant- thickness contours to analyze and utilize that behavior. From the analysis and understanding of the behavior of the TEF, and from the definition of a polarization device as a film-substrate system that introduces prescribed polarization changes, we discuss the design of all possible types of polarization devices using either of the two systems. We present a design formula for each. We also present a general formula that is used for the design of any of the devices. Thin-film coatings are treated as polarization devices for the purposes of our discussion. We conclude with a brief discussion of suggested practical modifications to, and simplifications of, ellipsometric memory, which is an interesting application of polarization devices for which there is a patent pending.

beta-Estradiol biodegradable microspheres: effect of formulation parameters on encapsulation efficiency and in vitro release.

The purpose of this work was to study the effect of organic solvent and surfactant type on the in vitro release behavior in general and on the burst release in particular of beta-estradiol from PLA/PLGA microspheres. Also the effect of these variables on the encapsulation efficiency was investigated. The microspheres were prepared by solvent evaporation technique using dichloromethane (DCM), ethyl acetate (EtAc), tetrahydrofuran (THF), chloroform (CHCl3) or acetone (AC) as organic solvent and polyvinyl alcohol (PVA), Tween 80, sodium lauryl sulfate (SLS) or benzalkonium chloride (BKCI) as surfactant. The obtained microspheres were tested for encapsulation efficiency and in vitro drug release using 50% methanol/buffer pH 7.4 as dissolution medium. EtAC and PVA formulations showed the highest encapsulation efficiency and the lowest burst release. These microspheres were further characterized for particle size distribution, SEM and zeta potential. The results suggested that these materials could be starting materials to prepare a beta-estradiol biodegradable controlled delivery system.

Unified analysis and mathematical representation of film-thickness behavior of film-substrate systems.

The ellipsometric function p of a film-substrate system is studied as the film thickness d is kept constant and the angle of incidence phi is changed. The generated constant-thickness contours (CTCs) are characterized by an introduced mathematical behavior indicator that represents a group of CTCs. The behavior of each group is developed and studied in the four planes phi-d, X, Z, and p, where X is the film-thickness exponential function and Z is a previously introduced intermediate plane. In the phi-d plane the film-thickness domain is identified and divided into a sequence of disconnected thickness subdomains (DTSs), depending on only N0 and N1, and their number depending on the range in which N0/N1 lies. The behavior of the CTCs in the successive planes X, Z, and p is then studied in each DTS, and the CTC's space is divided into disconnected subfamilies according to the behavior indicator. Equivalence classes that reduce the infinite number of subfamilies into a finite number are then introduced. The transformation from each plane to the next is studied with the origin of the Z plane mapped onto the point at infinity of the p plane, forming a singularity. A multiple-film-thickness inequality is derived to determine the unique solution of the film thickness. The type of reflection being internal or external at both ambient-film and film-substrate interfaces affects the analysis and is also considered. To conclude we introduce the design of polarization-preserving devices and a novel oscillating single-element ellipsometer to fully characterize zero film-substrate systems as examples of applying the knowledge developed here.

Unforced polarization-based optical implementation of Binary logic.

We present a new method to optically represent and implement binary logic, and we implement some unforced logic gates. The binary logic zero and one are taken to be an optical beam, or any electromagnetic wave, that is polarized at a selected state and its negation, orthogonal counterpart, or otherwise. In one implementation, a thin-film system is then designed and used so as it can move between 2 positions producing the net desired polarization change of the output. The output consists of a wave that is polarized either in the direction of the original logic 1 or 0 or any other chosen state and its negation, orthogonal counterpart. The system can be cascaded infinitely due to the fact that the output and input are both of the same format and that the logic zero and one are not dependant on the intensity of the input or the output light beam. The unforced gates exclusive OR and exclusive NOR along with a simple inverter are demonstrated in this communication. We present three design architectures, where each has two types of gates. In one type of gates the polarization state magnitude can carry information that can be employed for testability or reverse logic. XOR, XNOR, and inverter gate designs and operation are discussed in detail, and an easy-to-follow step-by-step algorithm is presented. The introduced architectures are easily adapted for simultaneous cascading, multiple input designs, and integrated optical architecture. * Patent Pending.

Complete all-optical processing polarization-based binary logic gates and optical processors.

We present a complete all-optical-processing polarization-based binary-logic system, by which any logic gate or processor can be implemented. Following the new polarization-based logic presented in [Opt. Express 14, 7253 (2006)], we develop a new parallel processing technique that allows for the creation of all-optical-processing gates that produce a unique output either logic 1 or 0 only once in a truth table, and those that do not. This representation allows for the implementation of simple unforced OR, AND, XOR, XNOR, inverter, and more importantly NAND and NOR gates that can be used independently to represent any Boolean expression or function. In addition, the concept of a generalized gate is presented which opens the door for reconfigurable optical processors and programmable optical logic gates. Furthermore, the new design is completely compatible with the old one presented in [Opt. Express 14, 7253 (2006)], and with current semiconductor based devices. The gates can be cascaded, where the information is always on the laser beam. The polarization of the beam, and not its intensity, carries the information. The new methodology allows for the creation of multiple-input-multiple-output processors that implement, by itself, any Boolean function, such as specialized or non-specialized microprocessors. Three all-optical architectures are presented: orthoparallel optical logic architecture for all known and unknown binary gates, singlebranch architecture for only XOR and XNOR gates, and the railroad (RR) architecture for polarization optical processors (POP). All the control inputs are applied simultaneously leading to a single time lag which leads to a very-fast and glitch-immune POP. A simple and easy-to-follow step-by-step algorithm is provided for the POP, and design reduction methodologies are briefly discussed. The algorithm lends itself systematically to software programming and computer-assisted design. As examples, designs of all binary gates, multiple-input gates, and sequential and non-sequential Boolean expressions are presented and discussed. The operation of each design is simply understood by a bullet train traveling at the speed of light on a railroad system preconditioned by the crossover states predetermined by the control inputs. The presented designs allow for optical processing of the information eliminating the need to convert it, back and forth, to an electronic signal for processing purposes. All gates with a truth table, including for example Fredkin, Toffoli, testable reversible logic, and threshold logic gates, can be designed and implemented using the railroad architecture. That includes any future gates not known today. Those designs and the quantum gates are not discussed in this paper.

Closed-form inversion of the reflection ellipsometric function of a film-substrate system: absorbing-substrate optical constant.

A closed-form inversion expression for obtaining the optical constant (complex refractive index) of the substrate of an absorbing-film-absorbing-substrate system from one reflection ellipsometry measurement is derived. If, in addition, the film thickness is to be determined, a second measurement at another angle of incidence may or may not be used. The derived formula does not introduce errors itself, and tolerates errors in input variables very well. Random and systematic errors in the measured ellipsometric parameters do not affect the value obtained for the optical constant of the substrate: it is always the true value to two decimal places. Two examples in ellipsometry and in the design of reflection-type optical devices, one each, are presented and discussed. In addition, experimental results for a commercially available wafer are also presented. Two other closed-form inversion expressions for obtaining the optical constant of the substrate from two and three measurements are also presented and briefly discussed.

Design of reflection retarders by use of nonnegative film-substrate systems.

A reflection-type film-substrate retarder is an optical device that changes the relative phase but not the relative amplitude of light upon reflection from a film-substrate system. While there are several such device designs based on the common negative film-substrate system, very little has been done with the other two categories of systems, zero and positive. The system category is determine by the relationship between the refractive indices of the ambient N0, film N1 and substrate N2. If N1 < square root of N0N2, the system is negative; if N1 = square root of N0N2, the system is zero; and if N1 > square root of N0N2, the system is positive. The design procedure and characteristics of zero-system reflection retarders are discussed. The polarization and ellipsometric properties of the positive system preclude the existence of a reflection retarder. First, a brief characterization of the zero and positive systems by means of constant-angle-of-incidence contours and constant-thickness contours of the ellipsometric function is presented and discussed. Then an algorithm outlining the design procedures is presented, and the characteristics of the obtained designs are optimized, analyzed, and discussed. The exact retarder is valid for a single wavelength at a set angle of incidence. The design tolerance to changes in the design parameters is analyzed and discussed. In general, N1 < or = square root of N1N2 is the condition to be satisfied to realize reflection-type retarders with film-substrate systems.

The adsorption of Cu(II) ions on bentonite--a kinetic study.

The kinetics of sorption of Cu(2+) on a Saudi clay mineral (bentonite) was investigated at 20+/-0.5 degrees C using different weights of the clay (0.5, 1.0, 1.5, and 2 g). Each weight represents a certain sample size. The order of the process appeared to be 1 with respect to the Cu(2+), and 112 with respect to the clay surface area. The rate was found to depend on internal diffusion.,which produced a decrease in the specific rate of sorption as a function of time. Sorption characteristics were described using two site Langmuir isotherms. The desorption experiments proved that Cu(2+) ions are chemisorbed on the bentonite surface. The maximum adsorption obtained was 909 mg Cu(2+)/g clay. This value is of great significance, as it is much higher than any reported one.

Bioavailability assessment of salbutamol sulfate suppositories in human volunteers.

The purpose of this investigation was to evaluate the bioavailability of three salbutamol sulfate suppository formulations. The formulations were; 2 mg salbutamol sulfate in Suppocire NA base containing 6% Eudispert gel (F1), 2mg salbutamol sulfate in Witepsol H15 base containing 3% methyl cellulose gel (F2), and 2 mg salbutamol sulfate in Witepsol W25 base containing 3% methyl cellulose gel (F3). The formulations were administered via rectal route in six healthy male adult volunteers. The bioavailability of the three suppository formulations was compared with the oral bioavailability of salbutamol sulfate 2mg tablets (F4). Six volunteers participated in a four-way crossover study, where each study was separated from the other by an interval of 1 weak. Venous blood samples of 5 ml were taken immediately before dosing and after predetermined time intervals of 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6 and 8 h. The result showed that Cmax +/- S.D. observed were 12.96 +/- 2.11, 14.78 +/- 2.33, 10.02 +/- 1.42 and 11.51 +/- 1.22 ng ml(-1) for F1, F2, F3 and F4, respectively. The Tmax +/- S.D. were found to be 1.91 +/- 0.20, 1.83 +/- 0.26, 2.50 +/- 0.00 and 2.67 +/- 0.24 h for F1, F2, F3 and F4, respectively. AUC +/- S.D. values were 40.25 +/- 1.88, 42.16 +/- 1.55, 28.62 +/- 1.98 and 37.63 +/- 1.44 ng h per ml for F1, F2, F3 and F4, respectively. The relative bioavailabilities of the investigated formulations were 112.04, 106.96 and 76.06 for formula F2, F1 and F3, respectively, when compared with the oral preparation (F4). The finding indicates that the bioavailability of salbutamol sulfate can be enhanced by delivering it rectally with Suppocire NA base containing 6% Eudispert gel or with Witepsol W25 base containing 3% methyl cellulose to match that of oral tablets. Salbutamol sulfate can be rectally administered in patients who are less compliant with the oral administration.